>> go get him! go get him now! >> reporter: a neighbor with a gun and a grudge. >> i thought, "they better get to him before i do." >> reporter: but some said this couple was having trouble. that seth had a secret. >> did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: others said the real murderer was someone else, right under cops' noses. >> here's a legitimate suspect that should have been investigated. >> reporter: a case unfolding on camera, one that would test three juries, shatter two families. >> just like somebody hit me in the stomach. >> reporter: and take one final twist -- >> that was her biggest secret. >> i'm lester holt and this is "dateline." here's dennis murphy with "before dawn." >> reporter: the cornfields of iowa are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yep, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. >> once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. >> bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children, all the while he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters. this time, he was getting lots of help from lisa. she was the twins' default babysitter. >> she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> they had a very close relationship? >> uh-huh. very. i would get into bed with her. we'd watch old episodes of "the golden girls." >> that's a sweet relationship. >> yeah. and she always says that i was dorothy, because i'm such a grouch all the time. but -- yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. i was the one that they had to pass the test with. >> reporter: the boyfriend who passed with flying colors was a kid named seth techel. he came from a longtime local family. his grandfather had been the umpteen terms mayor of ottumwa. mom was a social worker. dad owned a local bowling alley. and the bowling alley was where seth, as a young teen, began noticing lisa. his dad was her high-school coach and seth bowled almost -- but not quite -- as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend-girlfriend and that was fine with both their families. >> so you liked this young girl? >> oh, a lot. yeah. >> she was a part of our family. >> yeah. >> reporter: the techels were a church-going family and seth's mom lorraine remembers how the boy's compassion for others shone on a relief mission to mississippi after hurricane katrina. >> he just stood and talked to these folks for hours and hours. and they just became very good friends. and i have a lot of memories like that of seth. >> helping people? >> yup. >> reporter: and lisa wanted to help people, too. she followed her father into law enforcement. first as a reserve deputy in todd's sheriff's department and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop, because i didn't wanna have to worry about, you know, her inefficiencies maybe endangering her life. >> reporter: after years of hearing patrons at the bowling alley joke about when the two of them were going to get married, seth and lisa made the inevitable official. >> how do you find out they're gonna get hitched? >> seth actually came to our house and met with us and asked us our permission to marry lisa. >> old school? >> old school. >> reporter: after dating for seven-years, seth and lisa got married in october, 2011. she was 22; he was 21. >> i just told him that no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> reporter: lisa's sister -- another elvis namesake -- presley -- got much more than a brother-in-law with seth. >> he was my best friend. he was just kind of that other person that i could always go to. >> he called me, "dad." we told each other we loved each other. we hugged every time we left each other. i mean i felt as close to him as i did my son. >> reporter: for lisa it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> so how did lisa put up with you guys? >> she was kind of interested in the same things that all of us were. like, she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> better than seth. >> it sounds like you guys all would have been happy if she were your girlfriend. >> seth was lucky. >> reporter: lucky, for sure. but seth knew it was time to settle down and get a real job. like lisa he was drawn to uniformed service. he'd signed on as a volunteer firefighter and drew a paycheck as a security guard. but his father-in-law todd was helping him get a higher rung on the ladder with a soon-to-start job as a jailer for the sheriff's. >> reporter: they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> reporter: a new job, a young marriage and now more changes for seth. he was going to be a father. they'd picked a name for the unborn girl -- zoey maria. in may 2012 they were halfway through the pregnancy. seth and lisa, a baby on the way, were starting out their married life in this humble little trailer. it was a gift from his dad, perched on just a beautiful piece of property. it was a kind of starter home while they saved some money for the future. the only apparent cloud in the picture was an escalating feud with an across the fence neighbor here. there was bad blood. it happened at 5:00 in the morning. a sudden, horrifying sound that shattered two young lives. >> wapello county 911. what's your emergency? >> reporter: saturday, may 26, 2012. memorial day weekend. >> she's not breathing. >> does she have any medical problems? >> no, she's been shot. >> reporter: a shotgun blast had ended all the plans of mr. and mrs. seth techel. newlywed, mom-to-be, and now -- out of the blue -- victim of a violent attack. who would want to hurt lisa? when we return -- deputies race to the scene, where the shooter could be lurking anywhere. >> you didn't know if somebody coulda winged a shot at you? >> yeah, that was possible the whole time. applebee's let the fans put their favorite dishes on the famous 2 for $20 menu. i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. morning hank.icks qlearquil what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. ♪ [music] jackie's heart attack didn't come with a warning. today her doctor has her on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before you begin an aspirin regimen. so did you hear the new iphone is out? i'm getting one! sprint is offering this exclusive new plan with unlimited data. the plan is only $50 a month! $50? unlimited iphone! [glass shattering] so should we eat? the new sprint simply unlimited plan, exclusively for iphone 6. unlimited data, talk and text for just $50 a month. switch to sprint and we'll buy out your contract. it's the best value in wireless. reporter: it was the end of a long overnight shift for sheriff's deputy marty wonderlin -- the only deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday morning, marty relaxed and turned up the music in his cruiser. >> the ragged end of the shift for you, huh? >> yeah. i'm takin' my last little loop around the county and gonna watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 am, when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. >> i have now been advised this lady's just been shot. >> is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing ninety, marty raced to the house in under 10 minutes. he slowed along the rise of the gravel country road and stopped in the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just-- bent over, you know? >> what's he doing? >> sounds like he's crying. just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch considered him a friend, knew his wife lisa too, and her father todd was a respected fellow deputy. the unfolding tragedy had just become very personal. >> deputy, how do you set your brain in compartments, where you gotta be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> you didn't know if somebody coulda winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene -- the possibility of a live shooter still on the grounds -- marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn'ta done that. i wish i would -- >> why do you say that? >> well, 'cause i saw a lotta things that morning and now because of me, because of askin' him to, you know, come out there, he's gonna have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep but his cell phone was plugged in next to the bed always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter -- her best friend -- needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 mile an hour, you know? i'm an e.r. nurse. i'm thinkin' -- >> you're sort of in nurse mode there too? >> yeah. i was - i -- i'm thinkin', "well, you know, maybe if i get there fast enough, that --" >> minutes matter? >> there'll be something i can do. >> reporter: todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh, my god, oh, my god, oh, my god." i just remember that's all i could think and say is, "oh, my god, oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was gettin', like, a defibullator ready. it felt like forever. you know, and i'm askin' him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone along with her unborn daughter. lisa marie techel was just 23 years-old. >> i ran in there and -- you could tell that she was gone. >> so you went into the bedroom? you saw her? did you tend to her? >> yeah. i hold her -- i held her hand and -- i rubbed her belly and -- and i just said, "my lisa, my lisa." >> todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her layin' there. and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe -- but i don't even remember doin' that. "what happened?" >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> gotta start workin' it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ] go get him. go get him. now. >> reporter: coming up who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. >> reporter: when dateline continues. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. [ siri] hello. wh[cortana] name? hello siri. i'm cortana. we've already met. i'm sorry. i don't remember. that's ok. i can remember lots of things. like your favorite kinds of restaurants. i cannot remember that. i can remember appointments and help you get there on time. or that. or remember favorite news topics. or that either. siri, what can you remember? i remember when i was the only phone that talked. ♪ reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside -- shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. >> he punched his truck, and i said, "don't do that, seth, you know, let me see your hand. >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> was just bad. i mean, it-- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. >> how's that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's [bleep] laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the [bleep] shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the f--- did this. >> there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. >> we'll figure it out, brother. >> i can't [bleep] tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out . and already had a suspect. >> go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire. a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. >> this is this culmination of bad blood's been goin' on for a month's time or more now? >> uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yep. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. >> okay. >> and i'll tell - - i just - - they're good people. they really are. >> now this guy, brian tate, does he know that you're the father-in-law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to effect maybe what he does or doesn't do. >> and he thinks that's the source of his trouble? >> right. >> those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of -- a bell goes off like, "terrorism's kind of-- a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i s -- i notice -- a shotgun layin' on the ground, you know? and i'm like goin'-- that makes me feel a little -- >> does that make you a little twitchy? yeah. yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out okay, if you go out there, be careful. tate might be 1096 which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker, used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and uhm but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism - the "terrorism" - was getting worse. todd responded again. this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. oh, me too. but no i'm good i know where i'm headed. how about music? nah i don't really feel like- ♪ just the two of us ♪ we can make it if we-- what a fun drive. we always have so much fun. remember that one time we- okay. sure you loved your old iphone. but you'll love your free new iphone you trade it for even more. you are loved a lot. and in so many ways. and when you're wrapped in the comfort of pampers swaddlers with blanket-like softness and up to 12 hours of protection, all you feel is love. wishing you love, sleep and play. pampers. while a body in motion tends to stay in motion. staying active can ease arthritis symptoms but if you have arthritis, this can be difficult. prescription celebrex can help relieve arthritis pain, so your body can stay in motion. because just one 200mg celebrex a day can provide 24 hour relief for many with arthritis pain and inflammation. plus, in clinical studies, celebrex is proven to improve daily physical function so moving is easier. and it's not a narcotic. you and your doctor should balance the benefits with the risks. all prescription nsaids, like celebrex, ibuprofen, naproxen and meloxicam have the same cardiovascular warning. they all may increase the chance of heart attack or stroke, which can lead to death. this chance increases if you have heart disease or risk factors such as high blood pressure or when nsaids are taken for long periods. nsaids, like celebrex, increase the chance of serious skin or allergic reactions, or stomach and intestine problems, such as bleeding and ulcers, which can occur without warning and may cause death. patients also taking aspirin and the elderly are at increased risk for stomach bleeding and ulcers. don't take celebrex if you have bleeding in the stomach or intestine, or had an asthma attack, hives, other allergies to aspirin, nsaids or sulfonamides. get help right away if you have swelling of the face or throat, or trouble breathing. tell your doctor your medical history. and ask your doctor about celebrex. for a body in motion. and now celebrex may be available for as little as $4 a month. terms and conditions apply. to learn more, go to celebrex.com. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was 5 months pregnant. >> reporter: lisa's murder was the first in the farm town in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. >> todd and i began the same year at the sheriff's office together. i'd watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> so, whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriff's office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators were ready to confront the neighbor. >> so, the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car while deputy phillips and a partner drew line-of-fire detail, approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my -- my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming. everyone was poised for battle. everyone but, it turned out, brian tate. he wasn't armed or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so, the cops turned on a recorder and started asking questions. >> so, you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up until 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15 hour sleep alibi. though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this [ bleep ] that happened. but i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line. vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11 days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you -- you'd sit outside here. >> at night? >> at night. yeah. when's the last time you did that? >> oh. it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm, quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me so i'm kinda taking a different approach to life right now. >> i mean, when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. >> so, what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for later that day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i -- i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so, he went downtown and instructed his parents -- no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator and the tone of the investigation was about to change. coming up -- deputies learn that seth may be hiding something. >> i told 'em that seth had a trac phone. >> some kind of secret phone, huh? >> yeah. >> reporter: when "dateline" continues. us 2 for $20 menu. why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. dowlower... that's more like it! petsmart's prices on your favorite food brands just got lower! shop a wide assortment of food and save $7 on select nutro® natural choice® dry dog food, and save $20 when you buy 2 bags! petsmart®. all around the world the dedicated people of united airlines ♪ are there to support you. ♪ that's got your back friendly. ♪ reporter: todd and amy returned home. destroyed. and the longest day of their lives, wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that -- that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight-hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got underway. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. >> his story begins somewhere around 5:00 am. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't [ bleep ] protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete [ bleep ] jackass to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy-ass neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning: >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> -- to shoot a cop." and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay? >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. >> what was the story you told 'em, colton? >> i told 'em that seth had a trac phone. >> some kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair but he could walk at any moment. coming up -- more about seth's secret phone. seems it wasn't just for talking. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes and better than ever, starting at just $9.99. say yes to bowl after never ending bowl of your favorite pasta and more yes to savory new sauces like velvety roasted mushroom alfredo and spicy three meat, plus toppings like crispy chicken fritta. never ending pasta bowl, your favorite pasta, garden salad, and fresh baked breadsticks. it's all unlimited starting at $9.99, but just for a limited time. only at olive garden, we're all family here. enjoy unlimited soup, salad and breadsticks lunch just $6.99. and we're new to the pacific northwest. the rain, the mud -- babam! it's there. the outside comes in. it's kinda nasty so you start the towel-mop shuffle. where are you sun?! [ doorbell rings ] oh, wow, it's a swiffer wetjet. this puts my towel mopping to shame. whoa! ewww. sunshine is overrated, now we can get messy. [ laughs ] now we can get messy. could save you fifteen percent or more on car insurance. everybody knows that. well, did you know you that former pro football player ickey woods will celebrate almost anything? unh-uh. number 44... whoooo! forty-four, that's me! get some cold cuts... get some cold cuts... get some cold cuts! whooo! gimme some! geico. fifteen minutes could save you fifteen percent or more on car insurance. whoo! forty-four ladies, that's me! whoo...gonna get some cold cuts today! and this is the iphone 6 plus. they come with a thing called health, so they can help you track a lot of stuff. like today, i walked 3.8 miles. well, i ran 4.2 miles. well, i climbed 11 flights of stairs. well, i drank a smoothie that had 362 calories in it. well, i had a funnel cake that had 1230 calories in it. ♪ you know that's not good, right? it was good. it was delicious.♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ reporter: seth techel had gone downtown voluntarily but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room, seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> and this person had told him a story about a girl named rachel. >> reporter: but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair -- then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland. but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, hey, how was your day type of thing. >> would it be considered sexting? >> no. no. none of that. >> "what are you wearing?" >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking. you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no. everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes -- or? >> i never had sexual, sex with her. no, nothing oral, nothing like that. uh -- i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop -- >> they -- >> -- they didn't come out. >> -- didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so, thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was -- that was that. >> reporter: meanwhile, both dci agents, birmingham and thomas, had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special trac phone as a steamy hotline. >> i know they were exchanging photos. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton know about you texting rachel? >> uh-huh. >> did you tell him about it? >> yeah. >> this is an on-going investigation. and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night. today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on for close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> be confrontational, because the clock is ticking. and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us -- you're responsible for killing your wife. >> no, no, i'm not. no, i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel, i would get a divorce. i would not [ bleep ] kill my wife over something that small. you know what? right now, i guess i don't give a [ bleep ] what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> thank you, sir. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex. but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. >> you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure in some regards. >> why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100 percent certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at -- at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and maybe a crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? coming up -- one piece of the puzzle falls into place. >> boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. >> this has gotta be more than your brain can absorb. >> definitely. >> reporter: when "dateline" continues. health can change in a minute. so cvs health is changing healthcare. making it more accessible and affordable, with over 900 locations for walk-in medical care. and more on the way. minuteclinic. another innovation from cvs health. because health is everything. do you have something for pain? i have bayer aspirin. i'm not having a heart attack, it's my back. i mean bayer back & body. it works great for pain. bayer back & body provides effective relief for your tough pain. better? yeah...thanks for the tip! i read most of the book.. having a baby isn't gonna be that hard. you didn't read the book. i read some of the book. it's all about being prepared. proper nutrition... keeping the romance alive. level 7! and setting a good example. daddy's trying. we are so ready for this. life can surprise you. so can an allstate agent. from savings on a new car, to discounts on a great car seat. the good hands are doing more than ever before. that there's the guy who gets his salsa from new york city. new york city?! [ male announcer ] only pace has that big, bold kick. anything else just ain't right. pace. grab the southwest by the bottle. okay patrick, one more stop. anything else just ain't right. lets go base, shark, blitz. base, shark, blitz, break! when the game's on the line... okay, this is for the game. the nfl trusts duracell quantum to power their game day communication. flag nineteen, set hut! abort! abort! he's keeping it. hut! duracell quantum. lasts up to 35% longer than the competition. lisa pregnant with her first child has been killed by a shotgun blast. investigators have quickly zeroed in on two suspects. lisa's husband who may have been involved with another woman, and a neighbor who had an ongoing beef with the couple. starting with a bombshell arrest and leading up to an explosive secret revealed from beyond the grave. here again, dennis murphy. reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. >> one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer was not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." >> we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode -- and -- tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon -- and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa, and had just moved out. we showed lucas this photograph, taken of seth at his home. >> if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes. it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa -- but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. >> reporter: too long into this sunday morning search, over here by this big old tree, what do you hear? >> "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20-yards from the back door of the trailer. >> reporter: that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives: was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's "work" friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here -- someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: sounds like they were making out rather than having sex. >> yes, that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> reporter: would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect -- and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know? did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. >> reporter: so you only had one suspect at this point. >> yeah. one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. >> reporter: your fellow officers are there as they would be, you know, they, you know, want to show respect. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained -- still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. >> i said, "is this --a personal visit or a professional -- >> reporter: this condolences or somethin' else, huh? >> and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we -- we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders; he arrested his friend seth techel. a fellow deputy put the cuffs on him -- they were lisa's cuffs, the ones she'd used as a reserve deputy. >> reporter: this has gotta be just -- more than your brain can absorb. >> yeah. >> little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sherifff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife.3 f2 a continuación, seth techels even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. you want it ... until boom, it's bedtime! your mattress is a battleground of thwarted desire. enter the sleep number bed. designed to let couples sleep together in individualized comfort. he's the softy. his sleep number setting is 35. you're the rock, at 60. and snoring? sleep number's even got an adjustment for that. you can only find sleep number at a sleep number store. right now, save $400 on our most popular mattress. know better sleep with sleep number. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. to visibly reduce fine lines and wrinkles in just one week. .... any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now he'd returned to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pall bearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me?" i was so proud. >> i should've been able to be there and watch her become a mom. she was just a joy. >> mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. >> the coroner would think it was heart. >> yes. >> what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown, from the state's attorney general's office, worried that a jury might think the deranged, deceased neighbor did it. their plan had been to call tate as a witness. >> on the theory that the -- the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> february 2013, can you see yourself going into the courthouse? >> yeah. i remember. >> what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in-laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first-degree murder and nonconsensual termination of a pregnan pregnancy. >> what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> how were you gonna mess with him? >> fill five gallon buckets full of dog manure. and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law and the state agent who interviewed him the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dash-cam video, it became evidence for the prosecution. >> we feed the squirrels, birds birds, and deer. >> we were hopeful that the injury woujury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man, certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland, the other woman, to show up and tell her story. >> did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december 2011, which was two months after seth got married. >> it became more sexual. asking me to send pictures. or, i don't know, just showing off my body, i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common. and that he had tried working things out with lisa and they just weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th, when he learned that you were communicating with brandon, he said what? >> just give me two more weeks >> did you ask him what he meant, just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element, sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him? >> no. >> never had your clothes off? >> no, sir. >> and you kissed a few times? >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel? >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. >> you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter and jelly sandwich in a baggie left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. coming up -- in the jury room, deliberations and drama. >> he started pounding on the door saying that he wanted out of there. and we were in tears. >> reporter: when dateline continues. of what they're looking for. somebody who has sensitivity, they want relief from their sensitivity pain, but they also want the other things that are available in toothpaste. new sensodyne complete protection is designed specifically for sensitivity sufferers, but then, on the other side of the coin, it's also delivering on the other attributes that patients want out of a sensitivity toothpaste, delivering a complete package. i think dentists are going to want to recommend sensodyne complete protection. it's going to be a breath of fresh air for them. sensodyne complete protection. take and... exhale.in... aflac! and a gentle wavelike motion... aahhh- ahhhhhh. liberate your spine, ahhh-ahhhhhh aflac! and reach, toes blossoming... not that great at yoga. yeah, but when i slipped a disk he paid my claim in just four days. ahh! four days? yep. find out how fast aflac can pay you, at aflac.com. applebee's let the fans put thefamous 2 for $20 menu.the why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. (carter) making a mess.alent for but it's ok...our new kitchen is zoe proof. (announcer) the time saving frigidaire gallery smudgeproof appliances resist fingerprints. and clean easily. so now you have more time to savor all those "sweet" family moments. frigidaire gallery. our time-saving legend continues. find more of the brands you love at kohl's grand opening sale. find new styles from nike for girls and boys great savings on athletic shoes for the family. levi's for him - buy one get one half off! the latest looks from rock & republic. cute playwear from carter's. and introducing the new kuerig 2.0 brewer for cup or carafe. save even more when you shop late friday and early saturday. plus, everyone gets kohl's cash starting friday find your yes. kohl's. reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. >> they stay out and they stay out and they say out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and 3-full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is hereby granted. >> reporter: the judge declared a mistrial because of a hung jury. >> hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to re-try the case. the vote had been 10 to 2 for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven month ts --s later, october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells the daily treks to court. lives disrupted the new courtoom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," vs. seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his -- his own smiling face saying, "miss you bella." >> um-huh. >> is that a term of endearment that he called you, his bella? >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck." i love you. at 10:51 p.m. on may 24th of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her; i felt like she destroyed my sister's marriage and her life. >> rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth, but i think she's kinda been a victim as well. >> he's manic, he's up all the time. he could become volatile and agitated. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> the judge wasn't ready to give up. he told the jurors to keep trying. the emotions in the courtroom were raw. >> presley and i weren't crying, but you could hear us sniffling a little. >> i do not desire a jury to be influenced by the public. >> now it was the prosecutors turn to see. >> the defense is making a speech about the caldwell family to try to influence the jury, which i thought was ludicrous. i'll take this. >> to stand up here and suggest that anyone in the courtroom is making an attempt to intenti intentionally influence the jury is nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here." >> reporter: for more than a minute glaring, burning a hole in seth's back. if looks could kill -- >> there's just kind of an urge to move forward. >> to jump the rail? >> yeah. god please don't make me do that. just let me stand. >> what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. a mistrial is declared. unbelieveable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction -- this time 9 to 3 -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like, he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings but a brand-new defense team. >> i heard it about a week before the trial and it just like somebody hit me in the stomach. >> reporter: coming up the defense comes out swinging. >> we chose to focus on the sloppy work done by the law enforcement. there was no dna, fingerprint, confession. watch: when hair loses protein, it splits and fails the needle test. but with pantene, the advanced pro-v formula helps prevent protein loss and stop split ends before they start. so your hair passes the test with ease. put pantene to the test. for hair so healthy you shine. all around the world the dedicated people of united airlines ♪ are there to support you. ♪ that's got your back friendly. ♪ dos familias, 2 juicios. to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in -- in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement, there was absolutely no dna, fingerprint, confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? >> no, we forgot, or we didn't do it. >> whoops. >> whoops. >> reporter: the new defense team had a new story to tell. it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the bogeyman of the first two trials, brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> we were going to stay on our path, doing that, we made the decision to drop out the brian tate video interviews that we'd put in in the first two cases. >> reporter: the caldwells and techels had been put through the ringer for more than two years. their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person. >> did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing of you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july, 2014, -- for the third time, the state of iowa vs. seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three-hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, forever? >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well we talked, i told her i wasn't happy, she got mad, then sad, then i slept on the couch, so hello mrs. resuscitator. >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mister resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had, and that included explosive new evidence. this time, it was about lisa. coming up -- >> you found out the story that there was this guy, co-worker? >> yeah. >> was there another man in lisa's life, when "dateline" continues. depression, or unusual changes in mood or behavior. or swelling, trouble breathing, rash, hives, blisters, changes in eyesight including blurry vision, muscle pain with fever, tired feeling, or skin sores from diabetes. common side effects are dizziness, sleepiness, weight gain and swelling of hands, legs and feet. don't drink alcohol while taking lyrica. don't drive or use machinery until you know how lyrica affects you. those who have had a drug or alcohol problem may be more likely to misuse lyrica. having reduced pain is great, and i'm grateful for it. ask your doctor about lyrica and visit lyrica.com to learn about our $25 co-pay offer. ♪ ♪ ♪ ♪ ♪ we have a saying... mi coffee es su coffee. our way of inviting you to share what's ours. so between september 16th and the 29th, we want to treat you to a rich, smooth mccafé coffee for free. why would we do that? when you have something this delicious, you just have to share it. ...on the casa. ♪ coube a breakthrough wayrip to get immediate and long lasting sensitivity relief instead of sensitivity toothpaste? find out, with new crest sensi-stop strips. just apply to the gumline of sensitive teeth for a quick 10 minutes. the special ingredient forms a lasting barrier that provides immediate relief and up to one month of protection. crest sensi-stop strips. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. ♪ here's a good one seattle... what did geico say to the mariner? we could save you a boatload! ♪ foghorn sounds loudly ♪ what's seattle's favorite noise? the puget sound! ♪ foghorn sounds loudly ♪ all right, never mind doesn't matter. this is a classic. what does an alien seamstress sew with? a space needle! ♪ foghorn sounds loudly continuously ♪ oh come off it captain! geico. fifteen minutes could save you fifteen percent or more on car insurance. reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. go get him, now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel -- offered as seth's motive for murder in earlier trials -- was also minimized this time. >> good afternoon miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. >> tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man, right? >> correct. >> and the only time you'd actually seen him in person in your whole entire life was outside of work four or five times? >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the i's have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it? >> yeah, exactly. we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel? >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we, we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. >> you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. lisa's lover was a married man, a father of four. >> and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes, i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes, at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse, correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter has a lover was the cruellest blow yet. >> the first emotion i had is, "why? why, lisa," you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all? >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26th, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. >> cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? coming up --ed to and just about everyone else are in for a surprise. introducing vicks qlearquil allergy morning hank. what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. this is holly. her long day of outdoor adventure starts with knee pain. and a choice. take 6 tylenol in a day or just 2 aleve for all day relief. onward! applebee's let the fans put thefamous 2 for $20 menu.the i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. but do you know what's ine your skincare?- neutrogena naturals. a line of nutrient-rich skincare with pure, naturally derived ingredients, carefully chosen and clinically proven to cleanse, purify and moisturize... and you'll never find any harsh chemical sulfates, parabens or unnecessary additives. healthy skin-starts from within. neutrogena naturals. learn more at neutrogenanaturals.com. ♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ this time things were different. as seth techel walked into the courtroom and sat down, his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family. and certainly not at todd, his former father-in-law. >> this is the young guy you used to clap on the back and say, "i love you." >> "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one, we the jury find the defendant seth andrew techel guilty of murder in the first degree. count the, nonconsensual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. >> reporter: and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin. not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26th, and then, there's seth from may 26th on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. >> we know this family. i know it's not doug and lorraine's fault. it's not their family's fault -- that any of this happened. >> reporter: todd searched out doug. only three years before, they were all celebrating their kids' wedding together. >> reporter: doug and lorraine still support their son and say he didn't do what he's now convicted of doing. >> reporter: do you have a whisper of doubt, either of you? >> no, sir. >> none. whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment too. >> i started cryin'. it wasn't tears of sorrow. it was tears of joy. they had finally gotten this s-o-b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're going to have the last word on brian tate. this was an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held on september 10th. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley -- lisa's sister -- walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister and i no longer love you. >> reporter: and then the judge handed down the sentence. >> thank you, ms. caldwell. >> reporter: life in prison with no possibility of parole. ♪ >> reporter: when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. >> what are the figures in it, todd? >> reporter: first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook" movie and it's -- we've always said, if you're a bird, i'm a bird. you know, i mean, whatev-- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, this is part of lisa now." >> that's all for this edition of "dateline." we'll see you next friday at 9:00, 8:00 central. tomorrow music for change the global citizen festival, the concert headlined by jay-z and featuring carrie underwood and no doubt, plus lots of surprises all celebrating citizens who care. that's tomorrow at 9:00, 8:00 central. i'm lester holt. next -- we investigate bird and airplane collisions. workers are shooting the bird instead of using new humane technology. plus, flash flooding. wild weather that swept through the north day. the news is next. right now. rain, lightning and hail. parts of the bay area get pounded with dangerous weather. good friday evening. thank you for joining us. i'men i'men -- i'm jessica aguirre. >> the impact of unusual weather that slammed the bay area. in
go get him now! >> reporter: a neighbor with a gun and a grudge. >> i thought, "they better get to him before i do." >> reporter: but some said this couple was having trouble. that seth had a secret. >> did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: others said the real murderer was someone else, right under cops' noses. >> here's a legitimate suspect that should have been investigated. >> reporter: a case unfolding on camera, one that would test three juries, shatter two families. >> just like somebody hit me in the stomach. >> reporter: and take one final twist -- >> that was her biggest secret. >> i'm lester holt and this is "dateline." here's dennis murphy with "before dawn." >> reporter: the cornfields of iowa are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yep, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. >> once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. >> bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children, all the while he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters. this time, he was getting lots of help from lisa. she was the twins' default babysitter. >> she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> they had a very close relationship? >> uh-huh. very. i would get into bed with her. we'd watch old episodes of "the golden girls." >> that's a sweet relationship. >> yeah. and she always says that i was dorothy, because i'm such a grouch all the time. but -- yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. i was the one that they had to pass the test with. >> reporter: the boyfriend who passed with flying colors was a kid named seth techel. he came from a longtime local family. his grandfather had been the umpteen terms mayor of ottumwa. mom was a social worker. dad owned a local bowling alley. and the bowling alley was where seth, as a young teen, began noticing lisa. his dad was her high-school coach and seth bowled almost -- but not quite -- as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend-girlfriend and that was fine with both their families. >> so you liked this young girl? >> oh, a lot. yeah. >> she was a part of our family. >> yeah. >> reporter: the techels were a church-going family and seth's mom lorraine remembers how the boy's compassion for others shone on a relief mission to mississippi after hurricane katrina. >> he just stood and talked to these folks for hours and hours. and they just became very good friends. and i have a lot of memories like that of seth. >> helping people? >> yup. >> reporter: and lisa wanted to help people, too. she followed her father into law enforcement. first as a reserve deputy in todd's sheriff's department and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop, because i didn't wanna have to worry about, you know, her inefficiencies maybe endangering her life. >> reporter: after years of hearing patrons at the bowling alley joke about when the two of them were going to get married, seth and lisa made the inevitable official. >> how do you find out they're gonna get hitched? >> seth actually came to our house and met with us and asked us our permission to marry lisa. >> old school? >> old school. >> reporter: after dating for seven-years, seth and lisa got married in october, 2011. she was 22; he was 21. >> i just told him that no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> reporter: lisa's sister -- another elvis namesake -- presley -- got much more than a brother-in-law with seth. >> he was my best friend. he was just kind of that other person that i could always go to. >> he called me, "dad." we told each other we loved each other. we hugged every time we left each other. i mean i felt as close to him as i did my son. >> reporter: for lisa it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> so how did lisa put up with you guys? >> she was kind of interested in the same things that all of us were. like, she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> better than seth. >> it sounds like you guys all would have been happy if she were your girlfriend. >> seth was lucky. >> reporter: lucky, for sure. but seth knew it was time to settle down and get a real job. like lisa he was drawn to uniformed service. he'd signed on as a volunteer firefighter and drew a paycheck as a security guard. but his father-in-law todd was helping him get a higher rung on the ladder with a soon-to-start job as a jailer for the sheriff's. >> reporter: they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> reporter: a new job, a young marriage and now more changes for seth. he was going to be a father. they'd picked a name for the unborn girl -- zoey maria. in may 2012 they were halfway through the pregnancy. seth and lisa, a baby on the way, were starting out their married life in this humble little trailer. it was a gift from his dad, perched on just a beautiful piece of property. it was a kind of starter home while they saved some money for the future. the only apparent cloud in the picture was an escalating feud with an across the fence neighbor here. there was bad blood. it happened at 5:00 in the morning. a sudden, horrifying sound that shattered two young lives. >> wapello county 911. what's your emergency? >> reporter: saturday, may 26, 2012. memorial day weekend. >> she's not breathing. >> does she have any medical problems? >> no, she's been shot. >> reporter: a shotgun blast had ended all the plans of mr. and mrs. seth techel. newlywed, mom-to-be, and now -- out of the blue -- victim of a violent attack. who would want to hurt lisa? when we return -- deputies race to the scene, where the shooter could be lurking anywhere. >> you didn't know if somebody coulda winged a shot at you? >> yeah, that was possible the whole time. applebee's let the fans put their favorite dishes on the famous 2 for $20 menu. i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. morning hank.icks qlearquil what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. ♪ [music] jackie's heart attack didn't come with a warning. today her doctor has her on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before you begin an aspirin regimen. so did you hear the new iphone is out? i'm getting one! sprint is offering this exclusive new plan with unlimited data. the plan is only $50 a month! $50? unlimited iphone! [glass shattering] so should we eat? the new sprint simply unlimited plan, exclusively for iphone 6. unlimited data, talk and text for just $50 a month. switch to sprint and we'll buy out your contract. it's the best value in wireless. reporter: it was the end of a long overnight shift for sheriff's deputy marty wonderlin -- the only deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday morning, marty relaxed and turned up the music in his cruiser. >> the ragged end of the shift for you, huh? >> yeah. i'm takin' my last little loop around the county and gonna watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 am, when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. >> i have now been advised this lady's just been shot. >> is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing ninety, marty raced to the house in under 10 minutes. he slowed along the rise of the gravel country road and stopped in the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just-- bent over, you know? >> what's he doing? >> sounds like he's crying. just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch considered him a friend, knew his wife lisa too, and her father todd was a respected fellow deputy. the unfolding tragedy had just become very personal. >> deputy, how do you set your brain in compartments, where you gotta be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> you didn't know if somebody coulda winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene -- the possibility of a live shooter still on the grounds -- marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn'ta done that. i wish i would -- >> why do you say that? >> well, 'cause i saw a lotta things that morning and now because of me, because of askin' him to, you know, come out there, he's gonna have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep but his cell phone was plugged in next to the bed always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter -- her best friend -- needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 mile an hour, you know? i'm an e.r. nurse. i'm thinkin' -- >> you're sort of in nurse mode there too? >> yeah. i was - i -- i'm thinkin', "well, you know, maybe if i get there fast enough, that --" >> minutes matter? >> there'll be something i can do. >> reporter: todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh, my god, oh, my god, oh, my god." i just remember that's all i could think and say is, "oh, my god, oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was gettin', like, a defibullator ready. it felt like forever. you know, and i'm askin' him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone along with her unborn daughter. lisa marie techel was just 23 years-old. >> i ran in there and -- you could tell that she was gone. >> so you went into the bedroom? you saw her? did you tend to her? >> yeah. i hold her -- i held her hand and -- i rubbed her belly and -- and i just said, "my lisa, my lisa." >> todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her layin' there. and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe -- but i don't even remember doin' that. "what happened?" >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> gotta start workin' it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ] go get him. go get him. now. >> reporter: coming up who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. >> reporter: when dateline continues. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. [ siri] hello. wh[cortana] name? hello siri. i'm cortana. we've already met. i'm sorry. i don't remember. that's ok. i can remember lots of things. like your favorite kinds of restaurants. i cannot remember that. i can remember appointments and help you get there on time. or that. or remember favorite news topics. or that either. siri, what can you remember? i remember when i was the only phone that talked. ♪ exactly the way you want it... until boom, it's bedtime! your mattress is a battleground of thwarted desire. enter the sleep number bed. designed to let couples sleep together in individualized comfort. he's the softy. his sleep number setting is 35. you're the rock, at 60. and snoring? sleep number's even got an adjustment for that. you can only find sleep number at a sleep number store. right now, save $400 on our most popular mattress. know better sleep with sleep number. reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside -- shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. >> he punched his truck, and i said, "don't do that, seth, you know, let me see your hand. >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> was just bad. i mean, it-- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. >> how's that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's [bleep] laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the [bleep] shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the f--- did this. >> there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. >> we'll figure it out, brother. >> i can't [bleep] tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out . and already had a suspect. >> go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire. a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. >> this is this culmination of bad blood's been goin' on for a month's time or more now? >> uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yep. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. >> okay. >> and i'll tell - - i just - - they're good people. they really are. >> now this guy, brian tate, does he know that you're the father-in-law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to effect maybe what he does or doesn't do. >> and he thinks that's the source of his trouble? >> right. >> those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of -- a bell goes off like, "terrorism's kind of-- a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i s -- i notice -- a shotgun layin' on the ground, you know? and i'm like goin'-- that makes me feel a little -- >> does that make you a little twitchy? yeah. yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out okay, if you go out there, be careful. tate might be 1096 which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker, used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and uhm but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism - the "terrorism" - was getting worse. todd responded again. this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. oh, me too. but no i'm good i know where i'm headed. how about music? nah i don't really feel like- ♪ just the two of us ♪ we can make it if we-- what a fun drive. we always have so much fun. remember that one time we- okay. sure you loved your old iphone. but you'll love your free new iphone you trade it for even more. you are loved a lot. and in so many ways. and when you're wrapped in the comfort of pampers swaddlers with blanket-like softness and up to 12 hours of protection, all you feel is love. wishing you love, sleep and play. pampers. while a body in motion tends to stay in motion. staying active can ease arthritis symptoms but if you have arthritis, this can be difficult. prescription celebrex can help relieve arthritis pain, so your body can stay in motion. because just one 200mg celebrex a day can provide 24 hour relief for many with arthritis pain and inflammation. plus, in clinical studies, celebrex is proven to improve daily physical function so moving is easier. and it's not a narcotic. you and your doctor should balance the benefits with the risks. all prescription nsaids, like celebrex, ibuprofen, naproxen and meloxicam have the same cardiovascular warning. they all may increase the chance of heart attack or stroke, which can lead to death. this chance increases if you have heart disease or risk factors such as high blood pressure or when nsaids are taken for long periods. nsaids, like celebrex, increase the chance of serious skin or allergic reactions, or stomach and intestine problems, such as bleeding and ulcers, which can occur without warning and may cause death. patients also taking aspirin and the elderly are at increased risk for stomach bleeding and ulcers. don't take celebrex if you have bleeding in the stomach or intestine, or had an asthma attack, hives, other allergies to aspirin, nsaids or sulfonamides. get help right away if you have swelling of the face or throat, or trouble breathing. tell your doctor your medical history. and ask your doctor about celebrex. for a body in motion. and now celebrex may be available for as little as $4 a month. terms and conditions apply. to learn more, go to celebrex.com. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was 5 months pregnant. >> reporter: lisa's murder was the first in the farm town in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. >> todd and i began the same year at the sheriff's office together. i'd watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> so, whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriff's office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators were ready to confront the neighbor. >> so, the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car while deputy phillips and a partner drew line-of-fire detail, approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my -- my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming. everyone was poised for battle. everyone but, it turned out, brian tate. he wasn't armed or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so, the cops turned on a recorder and started asking questions. >> so, you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up until 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15 hour sleep alibi. though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this [ bleep ] that happened. but i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line. vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11 days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you -- you'd sit outside here. >> at night? >> at night. yeah. when's the last time you did that? >> oh. it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm, quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me so i'm kinda taking a different approach to life right now. >> i mean, when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. >> so, what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for later that day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i -- i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so, he went downtown and instructed his parents -- no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator and the tone of the investigation was about to change. coming up -- deputies learn that seth may be hiding something. >> i told 'em that seth had a trac phone. >> some kind of secret phone, huh? >> yeah. >> reporter: when "dateline" continues. us 2 for $20 menu. why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. dowlower... that's more like it! petsmart's prices on your favorite food brands just got lower! shop a wide assortment of food and save $7 on select nutro® natural choice® dry dog food, and save $20 when you buy 2 bags! petsmart®. and sneaking in without lifemoving the bed.sounds. and sneaking in without lifemoving the bed.sounds. reporter: todd and amy returned home. destroyed. and the longest day of their lives, wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that -- that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight-hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got underway. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. >> his story begins somewhere around 5:00 am. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't [ bleep ] protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete [ bleep ] jackass to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy-ass neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning: >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> -- to shoot a cop." and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay? >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. >> what was the story you told 'em, colton? >> i told 'em that seth had a trac phone. >> some kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair but he could walk at any moment. coming up -- more about seth's secret phone. seems it wasn't just for talking. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes and better than ever, starting at just $9.99. say yes to bowl after never ending bowl of your favorite pasta and more yes to savory new sauces like velvety roasted mushroom alfredo and spicy three meat, plus toppings like crispy chicken fritta. never ending pasta bowl, your favorite pasta, garden salad, and fresh baked breadsticks. it's all unlimited starting at $9.99, but just for a limited time. only at olive garden, we're all family here. enjoy unlimited soup, salad and breadsticks lunch just $6.99. and we're new to the pacific northwest. the rain, the mud -- babam! it's there. the outside comes in. it's kinda nasty so you start the towel-mop shuffle. where are you sun?! [ doorbell rings ] oh, wow, it's a swiffer wetjet. this puts my towel mopping to shame. whoa! ewww. sunshine is overrated, now we can get messy. [ laughs ] now we can get messy. could save you fifteen percent or more on car insurance. everybody knows that. well, did you know you that former pro football player ickey woods will celebrate almost anything? unh-uh. number 44... whoooo! forty-four, that's me! get some cold cuts... get some cold cuts... get some cold cuts! whooo! gimme some! geico. fifteen minutes could save you fifteen percent or more on car insurance. whoo! forty-four ladies, that's me! whoo...gonna get some cold cuts today! and this is the iphone 6 plus. they come with a thing called health, so they can help you track a lot of stuff. like today, i walked 3.8 miles. well, i ran 4.2 miles. well, i climbed 11 flights of stairs. well, i drank a smoothie that had 362 calories in it. well, i had a funnel cake that had 1230 calories in it. ♪ you know that's not good, right? it was good. it was delicious.♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ reporter: seth techel had gone downtown voluntarily but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room, seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> and this person had told him a story about a girl named rachel. >> reporter: but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair -- then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland. but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, hey, how was your day type of thing. >> would it be considered sexting? >> no. no. none of that. >> "what are you wearing?" >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking. you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no. everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes -- or? >> i never had sexual, sex with her. no, nothing oral, nothing like that. uh -- i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop -- >> they -- >> -- they didn't come out. >> -- didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so, thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was -- that was that. >> reporter: meanwhile, both dci agents, birmingham and thomas, had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special trac phone as a steamy hotline. >> i know they were exchanging photos. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton know about you texting rachel? >> uh-huh. >> did you tell him about it? >> yeah. >> this is an on-going investigation. and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night. today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on for close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> be confrontational, because the clock is ticking. and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us -- you're responsible for killing your wife. >> no, no, i'm not. no, i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel, i would get a divorce. i would not [ bleep ] kill my wife over something that small. you know what? right now, i guess i don't give a [ bleep ] what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> thank you, sir. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex. but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. >> you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure in some regards. >> why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100 percent certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at -- at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and maybe a crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? coming up -- one piece of the puzzle falls into place. >> boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. >> this has gotta be more than your brain can absorb. >> definitely. >> reporter: when "dateline" continues. health can change in a minute. so cvs health is changing healthcare. making it more accessible and affordable, with over 900 locations for walk-in medical care. and more on the way. minuteclinic. another innovation from cvs health. because health is everything. do you have something for pain? i have bayer aspirin. i'm not having a heart attack, it's my back. i mean bayer back & body. it works great for pain. bayer back & body provides effective relief for your tough pain. better? yeah...thanks for the tip! i read most of the book.. having a baby isn't gonna be that hard. you didn't read the book. i read some of the book. it's all about being prepared. proper nutrition... keeping the romance alive. level 7! and setting a good example. daddy's trying. we are so ready for this. life can surprise you. so can an allstate agent. from savings on a new car, to discounts on a great car seat. the good hands are doing more than ever before. that there's the guy who gets his salsa from new york city. new york city?! [ male announcer ] only pace has that big, bold kick. anything else just ain't right. pace. grab the southwest by the bottle. okay patrick, one more stop. anything else just ain't right. lets go base, shark, blitz. base, shark, blitz, break! when the game's on the line... okay, this is for the game. the nfl trusts duracell quantum to power their game day communication. flag nineteen, set hut! abort! abort! he's keeping it. hut! duracell quantum. lasts up to 35% longer than the competition. lisa pregnant with her first child has been killed by a shotgun blast. investigators have quickly zeroed in on two suspects. lisa's husband who may have been involved with another woman, and a neighbor who had an ongoing beef with the couple. starting with a bombshell arrest and leading up to an explosive secret revealed from beyond the grave. here again, dennis murphy. reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. >> one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer was not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." >> we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode -- and -- tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon -- and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa, and had just moved out. we showed lucas this photograph, taken of seth at his home. >> if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes. it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa -- but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. >> reporter: too long into this sunday morning search, over here by this big old tree, what do you hear? >> "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20-yards from the back door of the trailer. >> reporter: that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives: was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's "work" friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here -- someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: sounds like they were making out rather than having sex. >> yes, that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> reporter: would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect -- and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know? did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. >> reporter: so you only had one suspect at this point. >> yeah. one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. >> reporter: your fellow officers are there as they would be, you know, they, you know, want to show respect. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained -- still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. >> i said, "is this --a personal visit or a professional -- >> reporter: this condolences or somethin' else, huh? >> and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we -- we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders; he arrested his friend seth techel. a fellow deputy put the cuffs on him -- they were lisa's cuffs, the ones she'd used as a reserve deputy. >> reporter: this has gotta be just -- more than your brain can absorb. >> yeah. >> little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sherifff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife.3 f2 a continuación, seth techels even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. you want it ... until boom, it's bedtime! your mattress is a battleground of thwarted desire. enter the sleep number bed. designed to let couples sleep together in individualized comfort. he's the softy. his sleep number setting is 35. you're the rock, at 60. and snoring? sleep number's even got an adjustment for that. you can only find sleep number at a sleep number store. right now, save $400 on our most popular mattress. know better sleep with sleep number. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. to visibly reduce fine lines and wrinkles in just one week. .... any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now he'd returned to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pall bearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me?" i was so proud. >> i should've been able to be there and watch her become a mom. she was just a joy. >> mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. >> the coroner would think it was heart. >> yes. >> what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown, from the state's attorney general's office, worried that a jury might think the deranged, deceased neighbor did it. their plan had been to call tate as a witness. >> on the theory that the -- the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> february 2013, can you see yourself going into the courthouse? >> yeah. i remember. >> what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in-laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first-degree murder and nonconsensual termination of a pregnan pregnancy. >> what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> how were you gonna mess with him? >> fill five gallon buckets full of dog manure. and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law and the state agent who interviewed him the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dash-cam video, it became evidence for the prosecution. >> we feed the squirrels, birds birds, and deer. >> we were hopeful that the injury woujury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man, certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland, the other woman, to show up and tell her story. >> did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december 2011, which was two months after seth got married. >> it became more sexual. asking me to send pictures. or, i don't know, just showing off my body, i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common. and that he had tried working things out with lisa and they just weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th, when he learned that you were communicating with brandon, he said what? >> just give me two more weeks >> did you ask him what he meant, just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element, sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him? >> no. >> never had your clothes off? >> no, sir. >> and you kissed a few times? >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel? >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. >> you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter and jelly sandwich in a baggie left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. coming up -- in the jury room, deliberations and drama. >> he started pounding on the door saying that he wanted out of there. and we were in tears. >> reporter: when dateline continues. of what they're looking for. somebody who has sensitivity, they want relief from their sensitivity pain, but they also want the other things that are available in toothpaste. new sensodyne complete protection is designed specifically for sensitivity sufferers, but then, on the other side of the coin, it's also delivering on the other attributes that patients want out of a sensitivity toothpaste, delivering a complete package. i think dentists are going to want to recommend sensodyne complete protection. it's going to be a breath of fresh air for them. sensodyne complete protection. take and... exhale.in... aflac! and a gentle wavelike motion... aahhh- ahhhhhh. liberate your spine, ahhh-ahhhhhh aflac! and reach, toes blossoming... not that great at yoga. yeah, but when i slipped a disk he paid my claim in just four days. ahh! four days? yep. find out how fast aflac can pay you, at aflac.com. applebee's let the fans put thefamous 2 for $20 menu.the why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. (carter) making a mess.alent for but it's ok...our new kitchen is zoe proof. (announcer) the time saving frigidaire gallery smudgeproof appliances resist fingerprints. and clean easily. so now you have more time to savor all those "sweet" family moments. frigidaire gallery. our time-saving legend continues. find more of the brands you love at kohl's grand opening sale. find new styles from nike for girls and boys great savings on athletic shoes for the family. levi's for him - buy one get one half off! the latest looks from rock & republic. cute playwear from carter's. and introducing the new kuerig 2.0 brewer for cup or carafe. save even more when you shop late friday and early saturday. plus, everyone gets kohl's cash starting friday find your yes. kohl's. reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. >> they stay out and they stay out and they say out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and 3-full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is hereby granted. >> reporter: the judge declared a mistrial because of a hung jury. >> hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to re-try the case. the vote had been 10 to 2 for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven month ts --s later, october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells the daily treks to court. lives disrupted the new courtoom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," vs. seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his -- his own smiling face saying, "miss you bella." >> um-huh. >> is that a term of endearment that he called you, his bella? >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck." i love you. at 10:51 p.m. on may 24th of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her; i felt like she destroyed my sister's marriage and her life. >> rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth, but i think she's kinda been a victim as well. >> he's manic, he's up all the time. he could become volatile and agitated. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> the judge wasn't ready to give up. he told the jurors to keep trying. the emotions in the courtroom were raw. >> presley and i weren't crying, but you could hear us sniffling a little. >> i do not desire a jury to be influenced by the public. >> now it was the prosecutors turn to see. >> the defense is making a speech about the caldwell family to try to influence the jury, which i thought was ludicrous. i'll take this. >> to stand up here and suggest that anyone in the courtroom is making an attempt to intenti intentionally influence the jury is nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here." >> reporter: for more than a minute glaring, burning a hole in seth's back. if looks could kill -- >> there's just kind of an urge to move forward. >> to jump the rail? >> yeah. god please don't make me do that. just let me stand. >> what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. a mistrial is declared. unbelieveable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction -- this time 9 to 3 -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like, he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings but a brand-new defense team. >> i heard it about a week before the trial and it just like somebody hit me in the stomach. >> reporter: coming up the defense comes out swinging. >> we chose to focus on the sloppy work done by the law enforcement. there was no dna, fingerprint, confession. watch: when hair loses protein, it splits and fails the needle test. but with pantene, the advanced pro-v formula helps prevent protein loss and stop split ends before they start. so your hair passes the test with ease. put pantene to the test. for hair so healthy you shine. dos familias, 2 juicios. to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in -- in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement, there was absolutely no dna, fingerprint, confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? >> no, we forgot, or we didn't do it. >> whoops. >> whoops. >> reporter: the new defense team had a new story to tell. it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the bogeyman of the first two trials, brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> we were going to stay on our path, doing that, we made the decision to drop out the brian tate video interviews that we'd put in in the first two cases. >> reporter: the caldwells and techels had been put through the ringer for more than two years. their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person. >> did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing of you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july, 2014, -- for the third time, the state of iowa vs. seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three-hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, forever? >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well we talked, i told her i wasn't happy, she got mad, then sad, then i slept on the couch, so hello mrs. resuscitator. >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mister resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had, and that included explosive new evidence. this time, it was about lisa. coming up -- >> you found out the story that there was this guy, co-worker? >> yeah. >> was there another man in lisa's life, when "dateline" continues. depression, or unusual changes in mood or behavior. or swelling, trouble breathing, rash, hives, blisters, changes in eyesight including blurry vision, muscle pain with fever, tired feeling, or skin sores from diabetes. common side effects are dizziness, sleepiness, weight gain and swelling of hands, legs and feet. don't drink alcohol while taking lyrica. don't drive or use machinery until you know how lyrica affects you. those who have had a drug or alcohol problem may be more likely to misuse lyrica. having reduced pain is great, and i'm grateful for it. ask your doctor about lyrica and visit lyrica.com to learn about our $25 co-pay offer. ♪ ♪ ♪ ♪ ♪ we have a saying... mi coffee es su coffee. our way of inviting you to share what's ours. so between september 16th and the 29th, we want to treat you to a rich, smooth mccafé coffee for free. why would we do that? when you have something this delicious, you just have to share it. ...on the casa. ♪ coube a breakthrough wayrip to get immediate and long lasting sensitivity relief instead of sensitivity toothpaste? find out, with new crest sensi-stop strips. just apply to the gumline of sensitive teeth for a quick 10 minutes. the special ingredient forms a lasting barrier that provides immediate relief and up to one month of protection. crest sensi-stop strips. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. ♪ here's a good one seattle... what did geico say to the mariner? we could save you a boatload! ♪ foghorn sounds loudly ♪ what's seattle's favorite noise? the puget sound! ♪ foghorn sounds loudly ♪ all right, never mind doesn't matter. this is a classic. what does an alien seamstress sew with? a space needle! ♪ foghorn sounds loudly continuously ♪ oh come off it captain! geico. fifteen minutes could save you fifteen percent or more on car insurance. reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. go get him, now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel -- offered as seth's motive for murder in earlier trials -- was also minimized this time. >> good afternoon miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. >> tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man, right? >> correct. >> and the only time you'd actually seen him in person in your whole entire life was outside of work four or five times? >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the i's have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it? >> yeah, exactly. we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel? >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we, we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. >> you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. lisa's lover was a married man, a father of four. >> and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes, i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes, at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse, correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter has a lover was the cruellest blow yet. >> the first emotion i had is, "why? why, lisa," you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all? >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26th, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. >> cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? coming up --ed to and just about everyone else are in for a surprise. allergy morning hank. what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. this is holly. her long day of outdoor adventure starts with knee pain. and a choice. take 6 tylenol in a day or just 2 aleve for all day relief. onward! applebee's let the fans put thefamous 2 for $20 menu.the i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. but do you know what's ine your skincare?- neutrogena naturals. a line of nutrient-rich skincare with pure, naturally derived ingredients, carefully chosen and clinically proven to cleanse, purify and moisturize... and you'll never find any harsh chemical sulfates, parabens or unnecessary additives. healthy skin-starts from within. neutrogena naturals. learn more at neutrogenanaturals.com. ♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ this time things were different. as seth techel walked into the courtroom and sat down, his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family. and certainly not at todd, his former father-in-law. >> this is the young guy you used to clap on the back and say, "i love you." >> "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one, we the jury find the defendant seth andrew techel guilty of murder in the first degree. count the, nonconsensual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. >> reporter: and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin. not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26th, and then, there's seth from may 26th on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. >> we know this family. i know it's not doug and lorraine's fault. it's not their family's fault -- that any of this happened. >> reporter: todd searched out doug. only three years before, they were all celebrating their kids' wedding together. >> reporter: doug and lorraine still support their son and say he didn't do what he's now convicted of doing. >> reporter: do you have a whisper of doubt, either of you? >> no, sir. >> none. whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment too. >> i started cryin'. it wasn't tears of sorrow. it was tears of joy. they had finally gotten this s-o-b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're going to have the last word on brian tate. this was an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held on september 10th. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley -- lisa's sister -- walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister and i no longer love you. >> reporter: and then the judge handed down the sentence. >> thank you, ms. caldwell. >> reporter: life in prison with no possibility of parole. ♪ >> reporter: when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. >> what are the figures in it, todd? >> reporter: first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook" movie and it's -- we've always said, if you're a bird, i'm a bird. you know, i mean, whatev-- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, this is part of lisa now." >> that's all for this edition of "dateline." we'll see you next friday at 9:00, 8:00 central. tomorrow music for change the global citizen festival, the concert headlined by jay-z and featuring carrie underwood and no doubt, plus lots of surprises all celebrating citizens who care. that's tomorrow at 9:00, 8:00 central. i'm lester holt.
of the fence. a husband's lust -- >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: then, a wife's double life exposed. >> that was her biggest secret. a case that would test three juries and shatter two families. before uncovering one terrifying truth -- >> reporter: this has gotta be just more than your brain can absorb. >> definitely. >> it's heartbreaking. >> just like somebody hit me in the stomach. >> reporter: the cornfields of iowa. ♪ are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yup, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> lisa, look over here. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children. all the while, he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters this time, he was getting lots of help from lisa. she was the twins' default babysitter. she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> reporter: you had a very close relationship? >> uh-huh, very. i would get into bed with her. we'd watch old episodes of the golden girls. [ laughter ] >> reporter: that's a sweet relationship. >> yeah, and she always says that i was dorothy because i'm such a grouch all the time. [ laughter ] but yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. [ laughter ] i was the one that they had to pass the test with. the boyfriend who passed with flying colors was seth. he came from a long time local family. his grandfather was the mayor. the dad owned a local bowling alley. the bowling alley was where seth as a young teen began noticing lisa. his dad was her high school coach and seth bold almost but not quite as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend/girlfriend and that was fine with both families. >> you liked this young girl? >> a lot. >> she was a part of our family. >> they were a church going family and seth's mom remembers how the compassion shown on a relief mission to mississippi after hurricane katrina. >> he just would talk to the folks for hours and hours. they became very good friends. i have a lot of memories like that of seth. >> helping people. >> yeah. she followed her father into law enforcement and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop because i didn't want to have to worry about her inefficiencies maybe endangering her life. >> after years of hearing patrons at the bowling alley when they would get married, they made the inevitable official. >> how did you find out they were getting hitched? >> seth came to our house and met with us and asked us our permission to marry lisa. old school. >> old school. >> after dating for seven years, seth and lisa got married in october 2011. she was 22, he was 21. >> i just told him that, no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> she got much more than a brother-in-law with seth. >> he was my best friend and he was that other person that i could always go to. >> he called me dad. we told each other we loved each other. we hugged every time we left each other. i felt as close to him as i did my son. >> for lisa, it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> how did she put up with you guys? >> she was interested in the same things that all of us were. she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> sounds like you would have been happy if she were your girlfriend? >> seth was lucky. >> lucky for sure. but seth knew it was time to settle down and get a real job. like lisa, he was draund drawn to service. he drew a paycheck as a security guard. his father-in-law todd was helping him get a higher rung in the ladder. the soon to start job as a jailer for the sheriffs. >> >> they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> now more changes for seth. he was going to be a father. they picked a name for the unborn girl, zoe maria. in may 2012, they were halfway through the pregnancy. >> seth and lisa, a baby on the way were starting out their married life in this humble little trailer. it was a gift from his dad purchased on a beautiful piece of property. a starter home to save money for the future. the only apparent cloud in the with an across the fence neighbor. a sudden horrifying sound that shattered two young lives. >> 911. >> saturday, may 26, 2012, memorial day weekend. >> not breathing. >> does she have any medical problems? >> she's been shot. >> a shotgun blast that ended all the plans of mr. and mrs. seth. deputies raced to the scene where the shooter could be lurking anywhere. >> even though somebody could have winged a shot at you. >> that was possible the whole time. we did it charlie. at&t's network now has the nation's strongest lte signal. let's go tell everybody. we're doing things like putting lte radio's at the top of our towers. to maximize power. and give you the strong signal you deserve. that's awesome! isn't is awesome?! so ya'll optimizied it? we optimized it! people of earth... oh boy... ...america's strongest lte signal is here! ♪ by 1914 the dodge brothers quit the ford motor company and set out on their own. they believed in more, than the assembly line. they believed driving was a holy endeavor. a hundred years later, the dodge brothers spirit lives on. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. (kids laughing) you know i tried one of those bargain paper towels but i had to use so many sheets per spill the roll just disappeared. i knew i should've bought bounty bounty is 2x more absorbent and strong when wet. just look how much longer bounty lasts versus one of those bargain brand towels. and that's a good deal. bounty. the long lasting picker upper and now try new bounty nfl prints. available at walmart. when you ache and haven't slept... you're not you. tylenol® pm relieves pain and helps you fall fast asleep and stay asleep. we give you a better night. you're a better you all day. tylenol®. introducing light & fit protein shakes the new way to help make temptations shrink away on the go. a deliciously fresh and satisfying taste with 12 grams of protein 5 grams of fiber and 0% fat. new light & fit protein shakes. taste the power of satisfaction. ♪ dannon ♪ long overnight shift for sheriff's deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday >> reporter: it's the ragged end of the shift for you, huh? >> yeah, i'm taking my last little loop around the county and going to watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 a.m. when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. i have now been advised this lady's just been shot. >> reporter: is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing 90, marty raced to the house in under ten minutes. he slowed along the rise of the gravel country road and stopped at the end of the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> reporter: here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just bent over, you know? >> reporter: what's he doing? >> sounds like he's crying, just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch, considered him a friend, knew his wife lisa too. and her father, todd, was a respected, fellow deputy. the unfolding tragedy had just become very personal. >> reporter: deputy, how do you set your brain in compartments, where you got to be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> reporter: were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> reporter: you didn't know if somebody could have winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene, the possibility of a live shooter still on the grounds, marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her, but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." >> call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn't have done that. i wish i would -- >> reporter: why do you say that? >> well, because i saw a lot of things that morning and now because of me, because of asking him to, you know, come out there, he's going to have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep, but his cell phone was plugged in next to the bed, always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter, her best friend, needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 miles per hour, you know? i'm an e.r. nurse. i'm thinking -- >> reporter: you're sort of in nurse mode there too? >> yeah, i'm thinking, "well, you know, maybe if i get there fast enough -- >> minutes matter. >> there will be something i could do. todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh my god. oh my god, oh, my god." i just remember that's all i could think and say is, "oh, my god. oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was getting, like, a defibrillator ready. it felt like forever. you know, and i'm asking him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone. along with her unborn daughter. lisa marie techel was just 23 years old. >> i ran in there and you could tell that she was gone. >> reporter: so you went into the bedroom? you saw her? did you tend to her? >> yeah, i held her hand and i rubbed her belly and i just said, "my -- my lisa, my lisa." >> reporter: todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her laying there and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe, but i don't even remember doing that. >> what happened? >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> got to start working it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ]. go get him. go get him, now. >> reporter: who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. welcome to the most social car we've ever designed. the all-new nissan murano. nissan. innovation that excites. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. we live in a pick and choose world. choose, choose, choose. but at bedtime? ...why settle for this? enter sleep number, and the ultimate sleep number event, going on now. sleepiq technology tells you how well you slept and what adjustments you can make. you like the bed soft. he's more hardcore. so your sleep goes from good to great to wow! now we can all choose amazing sleep only at a sleep number store. right now save 50% on the ultimate limited edition bed. know better sleep with sleep number. >> reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside, shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. he punched his truck, and i said, "don't do that, seth, you know, let me see your hand." >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> it was just bad. i mean, it -- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. how'd that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the -- shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the -- did this. >> reporter: there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. we'll figure it out, brother. >> i can't -- tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out and already had a suspect. >> that -- go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire, a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. this is this culmination of bad blood's been goin' on for a month's time or more now? >> right. uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yup. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. okay. >> and i'll tell -- i just -- they're good people. they really are. >> reporter: now this guy, brian tate, does he know that you're the father-in- law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to affect maybe what he does or doesn't do. >> reporter: and he thinks that's the source of his trouble? >> right. >> reporter: those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of - - a bell goes off like, "terrorism's kind of a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i notice a shotgun layin' on the ground, you know? and i'm like goin' "that makes me feel a little --" >> reporter: does that make you a little twitchy? >> yeah, yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out there and gets hurt." okay, if you go out there, be careful. tate might be 1096, which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and um -- but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism -- the terrorism -- was getting worse. todd responded again, this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well, i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. >> reporter: did you think he was a risk, that this was -- >> yeah. yeah. >> reporter: a guy who was capable of flipping out? >> i -- i did. i did. >> reporter: and now, lisa was dead, and the trailer was a crime scene. marty wonderlin, the first deputy at the scene, already knew all about brian tate and had zeroed in on him as his candidate for prime suspect. all the direction is heading across the fence to this guy whose name is brian tate. >> it is. >> reporter: and police decided it was time to pay a visit to tate. they armored up and got out their long guns, not knowing what their suspect might do. >> if you're ballsy enough to break into a house, shoot lisa and make it back out, you're ballsy enough to do just about anything. >> reporter: coming up -- cops confront their man. >> i had my rifle out, locked and loaded. each year 17 billion toilet paper tubes are thrown away in the us alone. that's enough to fill the empire state building...twice. now there's scott naturals® tube-free bath tissue. get the premium softness you need... ...without the wasteful tube. toss the tube for good with scott naturals® tube-free. (coughing) coughing disrupts everyone's life. that's why there's delsym. delsym's advanced time release formula helps silence coughs for a full 12 hours. all night... or all day. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. my tempur-pedic made me fall in love with mornings again. i love how it conforms to my body. with tempur-pedic the whole bed is comfortable. it's the best thing we ever did for ourselves. it's helping to keep us young. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. ♪ ♪ ♪ ♪ ♪ we all want to leave our mark on the world. why not make yours in the classroom? teachers open young minds and inspire future leaders. if you truly want to be great, be a great teacher, the more you know. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was five months pregnant. >> reporter: lisa's murder was the first in the farmtown in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. todd and i began the same year at the sheriff's office together. i watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> reporter: whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriffs office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators, were ready to confront the neighbor. >> reporter: so the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> reporter: did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car, while deputy phillips and a partner drew line-of-fire detail -- approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my, my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming, everyone was poised for battle, everyone but, it turned out, brian tate. he wasn't armed, or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> reporter: this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so the cops turned on a recorder and started asking questions. you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up till 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15-hour sleep alibi, though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this that happened. but, i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line, vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11-days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you, you'd sit outside here. >> at night? >> at night, yeah. when's the last time you did that? >> oh, it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me, so i'm kinda taking a different approach to life right now. >> i mean when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. so what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for that same day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so he went downtown and instructed his parents no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator, and the tone of the investigation was about to change. deputies learn that seth may be hiding something. >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. it. but the more you learn about your coverage, the more gaps you might find. like how you thought you were covered for this. [boy] check it out,mom! [prof. burke]when you're really only covered for this. or how you figured you were covered for this. when you're actually paying for this. you might be surprised at what's hiding in your coverage. talk to farmers and get smarter about your insurance. ♪ we are farmers bum-pa-dum bum-bum-bum-bum ♪ these are our cats, wolf and bear. the cat hair is so constant, it's like it's growing out of the floor. it drives me crazy. can we do something about this? (doorbell) woah. it's a swiffer sweeper. it's working like a magnet. ohhh! shed all you like, wolf. jack's heart attack didn't come with a warning. today, his doctor has him on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before your begin an aspirin regimen. >> reporter: todd and amy returned home, destroyed. and the longest day of their lives wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got under way. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security, but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. his story begins somewhere around 5:00 a.m. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound, coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete -- to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning. >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> to shoot a cop." >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay. >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. what was the story you told 'em, colton? >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair, but he could walk at any moment. more about seth's secret phone. seems it wasn't just for talking. did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. i discovered a convenient way to moisturize every day. new nivea in-shower body lotion. first i wash... then i apply it to my wet skin. it moisturizes instantly. and lasts for more than 24 hours. then i quickly rinse off. my skin feels amazingly smooth with no sticky feel. so, i get dressed... ..and go. now i enjoy smooth skin every day. new nivea in-shower body lotion in the body lotion aisle. "...the levian family have been masters of jewelry design for centuries." this levian collection is amazing. maybe it's time to start your own. kay jewelers presents today's levian collection... featuring exclusive levian chocolate diamonds. including incredible limited edition styles like these. one more reason kay is the number-one jewelry store in america. it's... a work of art? ♪ every kiss begins with kay. ♪ to unlock the possibilities of tomorrow......"lift tab." behold the beauty of balance. crisp flakes of fiber-rich bran. answered by the perfect quantity of sun sweetened raisins. and with the sublime addition of ice-cold milk, the day begins. ♪sun'll come out, tomorrow♪ tomorrow is waiting. own it, with kellogg's® raisin bran see you at breakfast™. and delight in temptingly tart and sweet new kellogg's® raisin bran with cranberries. >> reporter: seth techel had gone downtown voluntarily, but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer, who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> reporter: and this person had told him a story about a girl named rachel. but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair, then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland, but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, "hey, how was your day type of thing." >> would it be considered sexting? >> no, no. none of that. >> what are you wearing? >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking, you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no, everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes or? >> i never had sexual -- sex with her. no, nothing oral, nothing like that. um, i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop. >> they -- >> they didn't come out. >> didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> reporter: which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was, that was that. >> reporter: meanwhile, both dci agents birmingham and thomas had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special track phone as a steamy hotline. >> i know they were exchanging photos. >> reporter: did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton, uh, know about you texting rachel? >> mm-hmm. >> did you tell him about it? >> yeah. >> this is an ongoing investigation, and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night, today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before, at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> reporter: be confrontational, because the clock is ticking. >> and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us you're responsible for killing your wife. >> no, no. i'm not, no. i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel i would get a divorce. i would not kill my wife over something that small. you know what? right now i guess i don't give a -- what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex, but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure, in some regards. >> reporter: why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100% certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and a maybe crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? one piece of the puzzle, falls into place. boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. this has gotta be more than your brain can absorb. >> definitely. if you have moderate to severe rheumatoid arthritis like me and you're talking to your rheumatologist about a biologic... this is humira. this is humira helping to relieve my pain and protect my joints from further damage. this is humira giving me new perspective. doctors have been prescribing humira for ten years. humira works for many adults. it targets and helps to block a specific source of inflammation that contributes to ra symptoms. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers including lymphoma have happened, as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment get tested for tb. tell your doctor if you've been to areas where certain fungal infections are common, and if you've had tb hepatitis b, are prone to infections, or have flu-like symptoms or sores. don't start humira if you have an infection. talk to your doctor and visit humira.com this is humira at work ♪ ♪ [ male announcer ] cats will do anything for the irresistible taste of temptations treats. what are you doing? oh, here check this out. ♪ ♪ [ meows ] temptations. cats can't resist. in a world full of dictates and conventions, could there be another way? ♪ ♪ la vie est belle la vie est belle, the eau de parfum, lancôme. receive a free gift. only at macy's your fragrance destination. >> reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> reporter: crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode and tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon, and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa and had just moved out. we showed lucas this photograph taken of seth at his home. if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes, it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> i told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa, but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. not too long into this sunday morning search, over here by this big old tree, what do you hear? >> i hear, "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20 yards from the back door of the trailer. boy, that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives -- was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's work friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here, someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: it sounds like they were making out rather than having sex. >> yeah, yes. that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby, and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect, and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know. did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. so you only had one suspect at this point. >> yeah, one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. your fellow officers are there as they would be, you know, they-- you know, want to show respect. >> right. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained, still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. i said, "is this a personal visit or professional --" >> reporter: is this condolences or somethin' else, huh? >> yeah, and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders, he arrested his friend seth techel. a fellow deputy put the cuffs on him. they were lisa's cuffs, the ones she'd used as a reserve deputy. so this has gotta be just more than your brain can absorb. >> definitely, yeah. >> reporter: little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sheriff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife. seth techel goes on trial. but before it even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> reporter: and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. toenail fungus? don't hide it... tackle it with new fda-approved jublia! jublia is a prescription medicine proven to treat toenail fungus. use jublia as instructed by your doctor. once applied jublia gets to the site of infection by going under, around and through the nail. most common side effects include ingrown toenail, application-site redness itching, swelling, burning or stinging, blisters, and pain. tackle it! ask your doctor now if new jublia is right for you. here at quicken loans, we like to go the extra mile for our clients. with the wassman family, it was 2,500 extra miles. we're the wassman family from skagway, alaska... livin' so far out i was runnin' into dead ends... happened to come across quicken loans online... walked over to the computer... i was able to see all the paperwork... while i was on the phone i was able to go through the checklist. they were quick and efficient. quicken loans is definitely engineered to amaze. they were just really there for us. is there an elk in your bed? with sleep number, now there's an adjustment for that. you can only find sleep number at a sleep number store. right now save 50% on the ultimate limited edition bed. know better sleep with sleep number. don't wait for awesome... totino's pizza rolls... ...gets you there in just 60 seconds. go bold with flavors that kick. release a devastating avalanche of taste on your tongue. bury yourself in the flavor full of sweet icing and filling. call off the hounds! rescue is unnecessary. pillsbury toaster strudel, the snow day of breakfasts. >> reporter: for lisa techel's family, it had been a heartbreaking, relentless week. thursday didn't promise to be any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now, he'd return to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pallbearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me? i was so proud. >> i should've been able to be there and -- and watch her become a mom. she was just a joy. >> reporter: mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. the coroner would think it was heart. >> yes. >> reporter: what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown -- from the state's attorney general's office -- worried that a jury might think the deranged, deceased, neighbor did it. their plan had been to call tate as a witness. >> on the theory that the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> reporter: february 2013, can you see yourself going into the courthouse? >> yeah, i remember. >> reporter: what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in- laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike, and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first degree murder and nonconsensual termination of a pregnancy. what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> reporter: how were you gonna mess with him? >> fill five gallon buckets full of dog manure and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law -- and the state agent who interviewed him -- the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dashcam video it became evidence for the prosecution. >> we feed the squirrels, birds and deer. >> we were hopeful that the jury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man. certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland -- the other woman -- to show up and tell her story. did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december, 2011, which was two months after seth got married. >> it became more sexual, asking me to send pictures. or, i don't know just showing off my body i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common and that he had tried working things out with lisa and things weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th when he learned that you were communicating with brandon, he said what? >> just give me two more weeks. >> did you ask him what he meant just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element -- sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him. >> no. >> never had your clothes off. >> no. >> and you kissed a few times. >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel. >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter- and-jelly sandwich, in a baggie, left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. in the jury room, deliberations -- and drama. >> he started pounding on the door saying that he wanted out of there. >> and we were in tears. all vegetarians, foodies and gastronauts kindly avert your eyes. you can't get juiciness like this from soy or quinoa. this is not greek yogurt. nor will that ever be kale! in its lifetime it won't be de-constructed or in-fused. and while it is massive... its ego is not. and therefore needs no introduction. ba da ba ba ba [ narrator ] mama sherman and the legion of super fans. wow! [ narrator ] on a mission to get richard to his campbell's chunky soup. it's new chunky beer-n-cheese with beef and bacon soup. i love it. and mama loves you. ♪ ♪ [coughing] dave, i'm sorry to interrupt... i gotta take a sick day tomorrow. dads don't take sick days, dads take nyquil. the nighttime, sniffling sneezing, coughing aching, fever, best sleep with a cold medicine. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. we come by almost every day to deliver your mail so if you have any packages you want to return you should just give them to us i mean, we're going to be there anyway why don't you just leave it for us to pick up? or you could always get in your car and take it back yourself yeah, us picking it up is probably your easiest option it's kind of a no brainer ok, well, good talk some cool things to pass onto your kids: your super heroes. your fashion sense. your love of reading. your uncanny ability to find parking spots. your fear of people who are different? not so much, the more you know. >> reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. they stay out and they stay out and they stay out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there. and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and three full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is granted. >> reporter: the judge declared a mistrial because of a hung jury. hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to retry the case. the vote had been ten to two for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven months later october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells, the daily treks to court, lives disrupted. the new courtroom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. >> reporter: other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," versus seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his, his own smiling face saying, "miss you bella." >> mm-hmm. >> is that a term of endearment that he called you, his bella. >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck. i love you" at 10:51 p.m. on may 24 of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her. i felt like she destroyed my sister's marriage and her life. >> reporter: todd, rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth but i think she's kinda been a victim as well. >> he's manic, he's up all the time. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> we're not going to reach a verdict. what's next? >> reporter todd, it's happening again. >> yep. and i'm thinking, "this is two months wortha trials and we're right back to the beginning." >> reporter: but the judge wasn't ready to give up. he told the jurors to keep trying. emotions in the open courtroom were raw, especially on the caldwell side. the jury couldn't help but hear it. >> presley and i were crying. we weren't crying uncontrollably or anything. but you could hear us sniffling a little. >> reporter: as the jury filed out, defense attorney steve gardner rose, to scold the spectators. stop the over-the-top outbursts, he said, or he'd demand a mistrial in fairness to his client. >> i do not desire this jury to be influenced by the public. >> reporter: now, it was the prosecutors turn to seethe. >> the defense is making this speech about the caldwell family trying to somehow influence the jury, which we thought was ludicrous, i squeezed andy's arm, and i said "i'll take this." >> to stand up here and suggest that anyone in the courtroom is trying or attempting to intentionally influence the jury is absolute nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here. >> reporter: for more than a minute, glaring, burning a hole in seth's back. if looks could kill. >> there's just kind of an urge to move forward. >> reporter: to jump the rail? >> yeah. god, please don't make me do that. just let me stand. >> reporter: what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was -- i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. >> a mistrial is declared. >> reporter: unbelievable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction, this time nine to three -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like -- he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings by a brand new defense team. >> i heard it about a week before the trial and it -- just like somebody hit me in the stomach. the defense comes out swinging, >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint, confession. [goat screams] ♪ elevator music ♪ [goat screams] ♪ elevator music ♪ [donkey braying] ♪ upbeat music ♪ bring in your verizon or at&t bill, turn in your old phone and we'll cut your rate plan in half. visit us online or visit a sprint store today man (sternly): where do you think you're going? mr. mucus: to work, with you. it's taco tuesday. man: you're not coming. i took mucinex to help get rid of my mucusy congestion. i'm go od all day. [announcer:] mucinex keeps working. not 4, not 6 but 12 hours. let's end this >> reporter: two families. two trials. and so far, no winners. but trial number three promised to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint -- confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? no, we forgot, or we didn't do it. >> reporter: whoops. >> whoops. >> reporter: the new defense team had a new story to tell -- it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the boogeyman of the first two trials -- brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> the caldwells and techels had been put through the wringer for more than two years, their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person." >> reporter: did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing with you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july 2014, for the third time, the state of iowa versus seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, "forever." >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well, we talked. i told her i wasn't happy, she got mad then sad, then i slept on the couch, so hello, mrs. resuscitator." >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mr. resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had and that included explosive new evidence. this time, it was about lisa. you've had this story. there was this guy, a co-worker. >> was there another man in lisa's life? when used at the first sign. without it the virus spreads from cell to cell. only abreva penetrates deep and starts to work immediately to block the virus and protect healthy cells. you could heal your cold sore, fast, as fast as two and a half days when used at the first sign. learn how abreva starts to work immediately at abreva.com don't tough it out knock it out, fast. with abreva. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. [announcer:] what if one stalk of broccoli could protect you from cancer? what if one push up could prevent heart disease? [man grunts] one wishful thinking, right? but there is one step you can take to help prevent another serious disease- pneumococcal pneumonia. one dose of the prevnar 13® vaccine can help protect you ... from pneumococcal pneumonia, an illness that can cause coughing, chest pain difficulty breathing and may even put you in the hospital. prevnar 13 ® is used in adults 50 and older to help prevent infections from 13 strains of the bacteria that cause pneumococcal pneumonia. you should not receive prevnar 13 ® if you've had a severe allergic reaction to the vaccine or its ingredients if you have a weakened immune system, you may have a lower response to the vaccine. common side effects were pain, redness, or swelling at the injection site. limited arm movement, fatigue, head ache muscle or joint pain less appetite, chills, or rash. even if you've already been vaccinated with another pneumonia vaccine, prevnar 13® may help provide additional protection. get this one done. ask your healthcare professional about prevnar 13® today. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. the bed reacts to your body. it hugs you. i don't have to think about how to get comfortable anymore. this zips off so i can wash it-yes, please. dude, tempur-pedic is killing it. no more tossin' and turnin', trying to find a comfortable spot in bed. it's really cool to the touch. my tempur-pedic... cuddles better than my husband does. but that's just between you and me. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. >> reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. get him. now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel, offered as seth's motive for murder in earlier trials, was also minimized this time. >> good afternoon, miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man right? >> correct. >> and the only time you'd actually seen him in person, in your whole entire life, outside of work, was four or five times. >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the ayes have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it. >> yeah exactly, we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel. >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we -- we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. >> lisa's lover was a married man, a father of four. >> reporter: and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter had a lover was the cruelest blow yet. >> the first emotion i had is, "why? why, lisa?" you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> reporter: does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all. >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. 'cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? todd, and just about everyone else, are in for a surprise. >> has this jury reached a verdict? i don't know what it is... the food, stress or running around but sometimes i feel bloated or gassy, with rumbling, uncomfortable. i feel sluggish and cranky. grrrr! (dog wimpers) you're right, bailey! i need a change! i'm taking the activia challenge! enjoying activia twice a day for four weeks may help reduce the frequency of minor digestive issues like bloating, gas discomfort and rumbling. and if your tummy smiles you can feel like you. try the activia challenge! it works or it's free! ♪ dannon ♪ start the interview with a firm handshake. firm, but not too firm. make eye contact...smile. ay,no! don't do that! try new head & shoulders instant relief. it has tea tree and peppermint that cools on contact. and also keeps you 100% flake free. i use it for cooling scalp relief in a snap. mi bebé ha crecido tanto. try new head & shoulders instant relief. for cooling relief in a snap. [ julie ] the wrinkle cream graveyard. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. ♪ miranda: ♪ i got red dirt stains on my boots and jeans. ♪ ♪ calloused fingers from my guitar strings. ♪ ♪ wild like the wind in the tall pine trees. ♪ ♪ i got roots and i got wings. ♪ ♪ with rollover data, the data you don't use this month rolls over to the next month. and i don't have to do anything? not a thing, mobile share value customers get it automatically. it's how we show appreciatn. you know i really appreciate that you appreciate me as a customer. and we appreciate how much you appreciate us appreciating our customers. and i appreciate that you appreciate that. and i appreciate you appreciating that. i appreciate that. aaaahhhh. introducing at&t rollover data. the data you don't use rolls over to the next month. all on the network with the nation's strongest lte signal. >> reporter: july 24, 2014. after two agonizing stalemates, this time things were different. as seth techel walked into the courtroom and sat down his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family, and certainly not at todd, his former father- in-law. this is the young guy you used to clap on the back and say, "i love you." >> yep. "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now, the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one -- we the jury find the defendant seth andrew techel guilty of murder in the first degree. signed by the head juror. count two -- non-consenual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin', not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26, and then, there's seth from may 26 on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent-up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. we know this family. i know it's not doug and lorraine's fault. it's not their family's fault that any of this happened. todd searched out doug. only three years before, they were all celebrating their kids' wedding together. doug and lorraine still support their son and say he didn't do what he's now convicted of doing. do you have a whisper of doubt, either of you? >> no, sir. >> none whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment, too. >> i started cryin'. it wasn't tears of sorrow, it was tears of joy. they had finally gotten this s.o.b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're gonna have last word on brian tate. this is an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held in september 2014. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley, lisa's sister, walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister, and i no longer love you. >> reporter: and then the judge handed down the sentence. life in prison, with no possibility of parole. when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. what are the figures in it, todd? >> the first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook," movie and it's -- we've always said, "if you're a bird, i'm a bird." you know, i mean, whatev -- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, is ipart of lisa now." >> 10 seconds! [ laughter ] >> ♪ now promenade your sweet, little maid ♪ ♪ take that girl and give 'er a whirl ♪ all right! give yourselves a big hand now! [ cheers and applause ] [ dramatic music plays ] >> johnny! >> johnny, i thought they fired you. >> well, they did, pete. but i gotta ask one last favor. can you call this?
a husband's lust -- >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: then, a wife's double life exposed. >> that was her biggest secret. a case that would test three juries and shatter two families. before uncovering one terrifying truth -- >> reporter: this has gotta be just more than your brain can absorb. >> definitely. >> it's heartbreaking. >> just like somebody hit me in the stomach. >> reporter: the cornfields of iowa. ♪ are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yup, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> lisa, look over here. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children. all the while, he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters this time, he was getting lots of help from lisa. she was the twins' default babysitter. she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> reporter: you had a very close relationship? >> uh-huh, very. i would get into bed with her. we'd watch old episodes of the golden girls. [ laughter ] >> reporter: that's a sweet relationship. >> yeah, and she always says that i was dorothy because i'm such a grouch all the time. [ laughter ] but yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. [ laughter ] i was the one that they had to pass the test with. the boyfriend who passed with flying colors was seth. he came from a long time local family. his grandfather was the mayor. the dad owned a local bowling alley. the bowling alley was where seth as a young teen began noticing lisa. his dad was her high school coach and seth bold almost but not quite as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend/girlfriend and that was fine with both families. >> you liked this young girl? >> a lot. >> she was a part of our family. >> they were a church going family and seth's mom remembers how the compassion shown on a relief mission to mississippi after hurricane katrina. >> he just would talk to the folks for hours and hours. they became very good friends. i have a lot of memories like that of seth. >> helping people. >> yeah. she followed her father into law enforcement and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop because i didn't want to have to worry about her inefficiencies maybe endangering her life. >> after years of hearing patrons at the bowling alley when they would get married, they made the inevitable official. >> how did you find out they were getting hitched? >> seth came to our house and met with us and asked us our permission to marry lisa. old school. >> old school. >> after dating for seven years, seth and lisa got married in october 2011. she was 22, he was 21. >> i just told him that, no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> she got much more than a brother-in-law with seth. >> he was my best friend and he was that other person that i could always go to. >> he called me dad. we told each other we loved each other. we hugged every time we left each other. i felt as close to him as i did my son. >> for lisa, it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> how did she put up with you guys? >> she was interested in the same things that all of us were. she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> sounds like you would have been happy if she were your girlfriend? >> seth was lucky. >> lucky for sure. but seth knew it was time to settle down and get a real job. like lisa, he was draund drawn to service. he drew a paycheck as a security guard. his father-in-law todd was helping him get a higher rung in the ladder. the soon to start job as a jailer for the sheriffs. >> >> they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> now more changes for seth. he was going to be a father. they picked a name for the unborn girl, zoe maria. in may 2012, they were halfway through the pregnancy. >> seth and lisa, a baby on the way were starting out their married life in this humble little trailer. it was a gift from his dad purchased on a beautiful piece of property. a starter home to save money for the future. the only apparent cloud in the with an across the fence neighbor. a sudden horrifying sound that shattered two young lives. >> 911. >> saturday, may 26, 2012, memorial day weekend. >> not breathing. >> does she have any medical problems? >> she's been shot. >> a shotgun blast that ended all the plans of mr. and mrs. seth. deputies raced to the scene where the shooter could be lurking anywhere. >> even though somebody could have winged a shot at you. >> that was possible the whole time. we did it charlie. at&t's network now has the nation's strongest lte signal. let's go tell everybody. we're doing things like putting lte radio's at the top of our towers. to maximize power. and give you the strong signal you deserve. that's awesome! isn't is awesome?! so ya'll optimizied it? we optimized it! people of earth... oh boy... ...america's strongest lte signal is here! ♪ by 1914 the dodge brothers quit the ford motor company and set out on their own. they believed in more, than the assembly line. they believed driving was a holy endeavor. a hundred years later, the dodge brothers spirit lives on. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. (kids laughing) you know i tried one of those bargain paper towels but i had to use so many sheets per spill the roll just disappeared. i knew i should've bought bounty bounty is 2x more absorbent and strong when wet. just look how much longer bounty lasts versus one of those bargain brand towels. and that's a good deal. bounty. the long lasting picker upper and now try new bounty nfl prints. available at walmart. when you ache and haven't slept... you're not you. tylenol® pm relieves pain and helps you fall fast asleep and stay asleep. we give you a better night. you're a better you all day. tylenol®. introducing light & fit protein shakes the new way to help make temptations shrink away on the go. a deliciously fresh and satisfying taste with 12 grams of protein 5 grams of fiber and 0% fat. new light & fit protein shakes. taste the power of satisfaction. ♪ dannon ♪ long overnight shift for sheriff's deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday >> reporter: it's the ragged end of the shift for you, huh? >> yeah, i'm taking my last little loop around the county and going to watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 a.m. when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. i have now been advised this lady's just been shot. >> reporter: is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing 90, marty raced to the house in under ten minutes. he slowed along the rise of the gravel country road and stopped at the end of the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> reporter: here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just bent over, you know? >> reporter: what's he doing? >> sounds like he's crying, just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch, considered him a friend, knew his wife lisa too. and her father, todd, was a respected, fellow deputy. the unfolding tragedy had just become very personal. >> reporter: deputy, how do you set your brain in compartments, where you got to be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> reporter: were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> reporter: you didn't know if somebody could have winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene, the possibility of a live shooter still on the grounds, marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her, but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." >> call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn't have done that. i wish i would -- >> reporter: why do you say that? >> well, because i saw a lot of things that morning and now because of me, because of asking him to, you know, come out there, he's going to have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep, but his cell phone was plugged in next to the bed, always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter, her best friend, needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 miles per hour, you know? i'm an e.r. nurse. i'm thinking -- >> reporter: you're sort of in nurse mode there too? >> yeah, i'm thinking, "well, you know, maybe if i get there fast enough -- >> minutes matter. >> there will be something i could do. todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh my god. oh my god, oh, my god." i just remember that's all i could think and say is, "oh, my god. oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was getting, like, a defibrillator ready. it felt like forever. you know, and i'm asking him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone. along with her unborn daughter. lisa marie techel was just 23 years old. >> i ran in there and you could tell that she was gone. >> reporter: so you went into the bedroom? you saw her? did you tend to her? >> yeah, i held her hand and i rubbed her belly and i just said, "my -- my lisa, my lisa." >> reporter: todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her laying there and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe, but i don't even remember doing that. >> what happened? >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> got to start working it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ]. go get him. go get him, now. >> reporter: who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. welcome to the most social car we've ever designed. the all-new nissan murano. nissan. innovation that excites. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. >> reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside, shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. he punched his truck, and i said, "don't do that, seth, you know, let me see your hand." >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> it was just bad. i mean, it -- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. how'd that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the -- shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the -- did this. >> reporter: there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. we'll figure it out, brother. >> i can't -- tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out and already had a suspect. >> that -- go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire, a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. this is this culmination of bad blood's been goin' on for a month's time or more now? >> right. uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yup. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. okay. >> and i'll tell -- i just -- they're good people. they really are. >> reporter: now this guy, brian tate, does he know that you're the father-in- law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to affect maybe what he does or doesn't do. >> reporter: and he thinks that's the source of his trouble? >> right. >> reporter: those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of - - a bell goes off like, "terrorism's kind of a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i notice a shotgun layin' on the ground, you know? and i'm like goin' "that makes me feel a little --" >> reporter: does that make you a little twitchy? >> yeah, yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out there and gets hurt." okay, if you go out there, be careful. tate might be 1096, which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and um -- but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism -- the terrorism -- was getting worse. todd responded again, this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well, i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. >> reporter: did you think he was a risk, that this was -- >> yeah. yeah. >> reporter: a guy who was capable of flipping out? >> i -- i did. i did. >> reporter: and now, lisa was dead, and the trailer was a crime scene. marty wonderlin, the first deputy at the scene, already knew all about brian tate and had zeroed in on him as his candidate for prime suspect. all the direction is heading across the fence to this guy whose name is brian tate. >> it is. >> reporter: and police decided it was time to pay a visit to tate. they armored up and got out their long guns, not knowing what their suspect might do. >> if you're ballsy enough to break into a house, shoot lisa and make it back out, you're ballsy enough to do just about anything. >> reporter: coming up -- cops confront their man. >> i had my rifle out, locked and loaded. each year 17 billion toilet paper tubes are thrown away in the us alone. that's enough to fill the empire state building...twice. now there's scott naturals® tube-free bath tissue. get the premium softness you need... ...without the wasteful tube. toss the tube for good with scott naturals® tube-free. (coughing) coughing disrupts everyone's life. that's why there's delsym. delsym's advanced time release formula helps silence coughs for a full 12 hours. all night... or all day. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. my tempur-pedic made me fall in love with mornings again. i love how it conforms to my body. with tempur-pedic the whole bed is comfortable. it's the best thing we ever did for ourselves. it's helping to keep us young. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. ♪ ♪ ♪ ♪ ♪ we all want to leave our mark on the world. why not make yours in the classroom? teachers open young minds and inspire future leaders. if you truly want to be great, be a great teacher, the more you know. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was five months pregnant. >> reporter: lisa's murder was the first in the farmtown in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. todd and i began the same year at the sheriff's office together. i watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> reporter: whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriffs office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators, were ready to confront the neighbor. >> reporter: so the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> reporter: did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car, while deputy phillips and a partner drew line-of-fire detail -- approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my, my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming, everyone was poised for battle, everyone but, it turned out, brian tate. he wasn't armed, or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> reporter: this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so the cops turned on a recorder and started asking questions. you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up till 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15-hour sleep alibi, though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this that happened. but, i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line, vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11-days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you, you'd sit outside here. >> at night? >> at night, yeah. when's the last time you did that? >> oh, it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me, so i'm kinda taking a different approach to life right now. >> i mean when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. so what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for that same day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so he went downtown and instructed his parents no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator, and the tone of the investigation was about to change. deputies learn that seth may be hiding something. >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. it. but the more you learn about your coverage, the more gaps you might find. like how you thought you were covered for this. [boy] check it out,mom! [prof. burke]when you're really only covered for this. or how you figured you were covered for this. when you're actually paying for this. you might be surprised at what's hiding in your coverage. talk to farmers and get smarter about your insurance. ♪ we are farmers bum-pa-dum bum-bum-bum-bum ♪ these are our cats, wolf and bear. the cat hair is so constant, it's like it's growing out of the floor. it drives me crazy. can we do something about this? (doorbell) woah. it's a swiffer sweeper. it's working like a magnet. ohhh! shed all you like, wolf. jack's heart attack didn't come with a warning. today, his doctor has him on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before your begin an aspirin regimen. thank you, cable for the slower internet upload speeds. for making me wait longer to share my photo albums. thank you cable, because if we never had you... ...we wouldn't know the incredible difference verizon fios makes. in customer satisfaction studies, fios is rated #1 in internet speed and reliability - 8 years running. plus, fios has the fastest wi-fi available from any provider. for a limited time, get a fios triple play online at an amazing $79.99 a month guaranteed for two years. plus, a $400 bonus with a two-year agreement hurry, deal ends february 21st. call the verizon center for customers with disabilities at 800.974.6006 tty/v >> reporter: todd and amy returned home, destroyed. and the longest day of their lives wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got under way. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security, but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. his story begins somewhere around 5:00 a.m. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound, coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete -- to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning. >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> to shoot a cop." >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay. >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. what was the story you told 'em, colton? >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair, but he could walk at any moment. more about seth's secret phone. seems it wasn't just for talking. did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. i discovered a convenient way to moisturize every day. new nivea in-shower body lotion. first i wash... then i apply it to my wet skin. it moisturizes instantly. and lasts for more than 24 hours. then i quickly rinse off. my skin feels amazingly smooth with no sticky feel. so, i get dressed... ..and go. now i enjoy smooth skin every day. new nivea in-shower body lotion in the body lotion aisle. "...the levian family have been masters of jewelry design for centuries." this levian collection is amazing. maybe it's time to start your own. kay jewelers presents today's levian collection... featuring exclusive levian chocolate diamonds. including incredible limited edition styles like these. one more reason kay is the number-one jewelry store in america. it's... a work of art? ♪ every kiss begins with kay. ♪ to unlock the possibilities of tomorrow......"lift tab." behold the beauty of balance. crisp flakes of fiber-rich bran. answered by the perfect quantity of sun sweetened raisins. and with the sublime addition of ice-cold milk, the day begins. ♪sun'll come out, tomorrow♪ tomorrow is waiting. own it, with kellogg's® raisin bran see you at breakfast™. and delight in temptingly tart and sweet new kellogg's® raisin bran with cranberries. >> reporter: seth techel had gone downtown voluntarily, but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer, who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> reporter: and this person had told him a story about a girl named rachel. but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair, then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland, but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, "hey, how was your day type of thing." >> would it be considered sexting? >> no, no. none of that. >> what are you wearing? >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking, you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no, everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes or? >> i never had sexual -- sex with her. no, nothing oral, nothing like that. um, i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop. >> they -- >> they didn't come out. >> didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> reporter: which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was, that was that. >> reporter: meanwhile, both dci agents birmingham and thomas had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special track phone as a steamy hotline. >> i know they were exchanging photos. >> reporter: did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton, uh, know about you texting rachel? >> mm-hmm. >> did you tell him about it? >> yeah. >> this is an ongoing investigation, and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night, today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before, at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> reporter: be confrontational, because the clock is ticking. >> and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us you're responsible for killing your wife. >> no, no. i'm not, no. i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel i would get a divorce. i would not kill my wife over something that small. you know what? right now i guess i don't give a -- what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex, but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure, in some regards. >> reporter: why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100% certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and a maybe crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? one piece of the puzzle, falls into place. boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. this has gotta be more than your brain can absorb. >> definitely. if you have moderate to severe rheumatoid arthritis like me and you're talking to your rheumatologist about a biologic... this is humira. this is humira helping to relieve my pain and protect my joints from further damage. this is humira giving me new perspective. doctors have been prescribing humira for ten years. humira works for many adults. it targets and helps to block a specific source of inflammation that contributes to ra symptoms. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers including lymphoma have happened, as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment get tested for tb. tell your doctor if you've been to areas where certain fungal infections are common, and if you've had tb hepatitis b, are prone to infections, or have flu-like symptoms or sores. don't start humira if you have an infection. talk to your doctor and visit humira.com this is humira at work ♪ ♪ [ male announcer ] cats will do anything for the irresistible taste of temptations treats. what are you doing? oh, here check this out. ♪ ♪ [ meows ] temptations. cats can't resist. in a world full of dictates and conventions, could there be another way? ♪ ♪ la vie est belle la vie est belle, the eau de parfum, lancôme. receive a free gift. only at macy's your fragrance destination. >> reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> reporter: crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode and tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon, and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa and had just moved out. we showed lucas this photograph taken of seth at his home. if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes, it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> i told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa, but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. not too long into this sunday morning search, over here by this big old tree, what do you hear? >> i hear, "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20 yards from the back door of the trailer. boy, that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives -- was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's work friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here, someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: it sounds like they were making out rather than having sex. >> yeah, yes. that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby, and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect, and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know. did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. so you only had one suspect at this point. >> yeah, one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. your fellow officers are there as they would be, you know, they-- you know, want to show respect. >> right. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained, still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. i said, "is this a personal visit or professional --" >> reporter: is this condolences or somethin' else, huh? >> yeah, and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders, he arrested his friend seth techel. a fellow deputy put the cuffs on him. they were lisa's cuffs, the ones she'd used as a reserve deputy. so this has gotta be just more than your brain can absorb. >> definitely, yeah. >> reporter: little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sheriff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife. seth techel goes on trial. but before it even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> reporter: and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. toenail fungus? don't hide it... tackle it with new fda-approved jublia! jublia is a prescription medicine proven to treat toenail fungus. use jublia as instructed by your doctor. once applied jublia gets to the site of infection by going under, around and through the nail. most common side effects include ingrown toenail, application-site redness itching, swelling, burning or stinging, blisters, and pain. tackle it! ask your doctor now if new jublia is right for you. here at quicken loans, we like to go the extra mile for our clients. with the wassman family, it was 2,500 extra miles. we're the wassman family from skagway, alaska... livin' so far out i was runnin' into dead ends... happened to come across quicken loans online... walked over to the computer... i was able to see all the paperwork... while i was on the phone i was able to go through the checklist. they were quick and efficient. quicken loans is definitely engineered to amaze. they were just really there for us. others. now, americans everywhere are discovering that... spoon after spoon... dish after dish... time, after time, after time again... deliciously creamy galbani ricotta inspires meals, and moments, that are simply better. mmm, galbani (sfx: kiss). italy's favorite cheese brand. now, america's number one ricotta. >> reporter: for lisa techel's family, it had been a heartbreaking, relentless week. thursday didn't promise to be any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now, he'd return to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pallbearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me? i was so proud. >> i should've been able to be there and -- and watch her become a mom. she was just a joy. >> reporter: mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. the coroner would think it was heart. >> yes. >> reporter: what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown -- from the state's attorney general's office -- worried that a jury might think the deranged, deceased, neighbor did it. their plan had been to call tate as a witness. >> on the theory that the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> reporter: february 2013, can you see yourself going into the courthouse? >> yeah, i remember. >> reporter: what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in- laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike, and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first degree murder and nonconsensual termination of a pregnancy. what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> reporter: how were you gonna mess with him? >> fill five gallon buckets full of dog manure and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law -- and the state agent who interviewed him -- the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dashcam video it became evidence for the prosecution. >> we feed the squirrels, birds and deer. >> we were hopeful that the jury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man. certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland -- the other woman -- to show up and tell her story. did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december, 2011, which was two months after seth got married. >> it became more sexual, asking me to send pictures. or, i don't know just showing off my body i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common and that he had tried working things out with lisa and things weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th when he learned that you were communicating with brandon, he said what? >> just give me two more weeks. >> did you ask him what he meant just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element -- sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him. >> no. >> never had your clothes off. >> no. >> and you kissed a few times. >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel. >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter- and-jelly sandwich, in a baggie, left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. in the jury room, deliberations -- and drama. >> he started pounding on the door saying that he wanted out of there. >> and we were in tears. all vegetarians, foodies and gastronauts kindly avert your eyes. you can't get juiciness like this from soy or quinoa. this is not greek yogurt. nor will that ever be kale! in its lifetime it won't be de-constructed or in-fused. and while it is massive... its ego is not. and therefore needs no introduction. ba da ba ba ba [ narrator ] mama sherman and the legion of super fans. wow! [ narrator ] on a mission to get richard to his campbell's chunky soup. it's new chunky beer-n-cheese with beef and bacon soup. i love it. and mama loves you. ♪ ♪ [coughing] dave, i'm sorry to interrupt... i gotta take a sick day tomorrow. dads don't take sick days, dads take nyquil. the nighttime, sniffling sneezing, coughing aching, fever, best sleep with a cold medicine. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. we come by almost every day to deliver your mail so if you have any packages you want to return you should just give them to us i mean, we're going to be there anyway why don't you just leave it for us to pick up? or you could always get in your car and take it back yourself yeah, us picking it up is probably your easiest option it's kind of a no brainer ok, well, good talk some cool things to pass onto your kids: your super heroes. your fashion sense. your love of reading. your uncanny ability to find parking spots. your fear of people who are different? not so much, the more you know. >> reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. they stay out and they stay out and they stay out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there. and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and three full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is granted. >> reporter: the judge declared a mistrial because of a hung jury. hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to retry the case. the vote had been ten to two for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven months later october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells, the daily treks to court, lives disrupted. the new courtroom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. >> reporter: other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," versus seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his, his own smiling face saying, "miss you bella." >> mm-hmm. >> is that a term of endearment that he called you, his bella. >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck. i love you" at 10:51 p.m. on may 24 of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her. i felt like she destroyed my sister's marriage and her life. >> reporter: todd, rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth but i think she's kinda been a victim as well. >> he's manic, he's up all the time. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> we're not going to reach a verdict. what's next? >> reporter todd, it's happening again. >> yep. and i'm thinking, "this is two months wortha trials and we're right back to the beginning." >> reporter: but the judge wasn't ready to give up. he told the jurors to keep trying. emotions in the open courtroom were raw, especially on the caldwell side. the jury couldn't help but hear it. >> presley and i were crying. we weren't crying uncontrollably or anything. but you could hear us sniffling a little. >> reporter: as the jury filed out, defense attorney steve gardner rose, to scold the spectators. stop the over-the-top outbursts, he said, or he'd demand a mistrial in fairness to his client. >> i do not desire this jury to be influenced by the public. >> reporter: now, it was the prosecutors turn to seethe. >> the defense is making this speech about the caldwell family trying to somehow influence the jury, which we thought was ludicrous, i squeezed andy's arm, and i said "i'll take this." >> to stand up here and suggest that anyone in the courtroom is trying or attempting to intentionally influence the jury is absolute nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here. >> reporter: for more than a minute, glaring, burning a hole in seth's back. if looks could kill. >> there's just kind of an urge to move forward. >> reporter: to jump the rail? >> yeah. god, please don't make me do that. just let me stand. >> reporter: what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was -- i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. >> a mistrial is declared. >> reporter: unbelievable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction, this time nine to three -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like -- he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings by a brand new defense team. >> i heard it about a week before the trial and it -- just like somebody hit me in the stomach. the defense comes out swinging, >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint, confession. [goat screams] ♪ elevator music ♪ [goat screams] ♪ elevator music ♪ [donkey braying] ♪ upbeat music ♪ bring in your verizon or at&t bill, turn in your old phone and we'll cut your rate plan in half. visit us online or visit a sprint store today man (sternly): where do you think you're going? mr. mucus: to work, with you. it's taco tuesday. man: you're not coming. i took mucinex to help get rid of my mucusy congestion. i'm go od all day. [announcer:] mucinex keeps working. not 4, not 6 but 12 hours. let's end this >> reporter: two families. two trials. and so far, no winners. but trial number three promised to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint -- confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? no, we forgot, or we didn't do it. >> reporter: whoops. >> whoops. >> reporter: the new defense team had a new story to tell -- it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the boogeyman of the first two trials -- brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> the caldwells and techels had been put through the wringer for more than two years, their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person." >> reporter: did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing with you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july 2014, for the third time, the state of iowa versus seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, "forever." >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well, we talked. i told her i wasn't happy, she got mad then sad, then i slept on the couch, so hello, mrs. resuscitator." >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mr. resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had and that included explosive new evidence. this time, it was about lisa. you've had this story. there was this guy, a co-worker. >> was there another man in lisa's life? when used at the first sign. without it the virus spreads from cell to cell. only abreva penetrates deep and starts to work immediately to block the virus and protect healthy cells. you could heal your cold sore, fast, as fast as two and a half days when used at the first sign. learn how abreva starts to work immediately at abreva.com don't tough it out knock it out, fast. with abreva. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. [announcer:] what if one stalk of broccoli could protect you from cancer? what if one push up could prevent heart disease? [man grunts] one wishful thinking, right? but there is one step you can take to help prevent another serious disease- pneumococcal pneumonia. one dose of the prevnar 13® vaccine can help protect you ... from pneumococcal pneumonia, an illness that can cause coughing, chest pain difficulty breathing and may even put you in the hospital. prevnar 13 ® is used in adults 50 and older to help prevent infections from 13 strains of the bacteria that cause pneumococcal pneumonia. you should not receive prevnar 13 ® if you've had a severe allergic reaction to the vaccine or its ingredients if you have a weakened immune system, you may have a lower response to the vaccine. common side effects were pain, redness, or swelling at the injection site. limited arm movement, fatigue, head ache muscle or joint pain less appetite, chills, or rash. even if you've already been vaccinated with another pneumonia vaccine, prevnar 13® may help provide additional protection. get this one done. ask your healthcare professional about prevnar 13® today. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. the bed reacts to your body. it hugs you. i don't have to think about how to get comfortable anymore. this zips off so i can wash it-yes, please. dude, tempur-pedic is killing it. no more tossin' and turnin', trying to find a comfortable spot in bed. it's really cool to the touch. my tempur-pedic... cuddles better than my husband does. but that's just between you and me. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. >> reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. get him. now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel, offered as seth's motive for murder in earlier trials, was also minimized this time. >> good afternoon, miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man right? >> correct. >> and the only time you'd actually seen him in person, in your whole entire life, outside of work, was four or five times. >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the ayes have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it. >> yeah exactly, we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel. >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we -- we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. >> lisa's lover was a married man, a father of four. >> reporter: and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter had a lover was the cruelest blow yet. >> the first emotion i had is, "why? why, lisa?" you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> reporter: does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all. >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. 'cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? todd, and just about everyone else, are in for a surprise. >> has this jury reached a verdict? i don't know what it is... the food, stress or running around but sometimes i feel bloated or gassy, with rumbling, uncomfortable. i feel sluggish and cranky. grrrr! (dog wimpers) you're right, bailey! i need a change! i'm taking the activia challenge! enjoying activia twice a day for four weeks may help reduce the frequency of minor digestive issues like bloating, gas discomfort and rumbling. and if your tummy smiles you can feel like you. try the activia challenge! it works or it's free! ♪ dannon ♪ start the interview with a firm handshake. firm, but not too firm. make eye contact...smile. ay,no! don't do that! try new head & shoulders instant relief. it has tea tree and peppermint that cools on contact. and also keeps you 100% flake free. i use it for cooling scalp relief in a snap. mi bebé ha crecido tanto. try new head & shoulders instant relief. for cooling relief in a snap. [ julie ] the wrinkle cream graveyard. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. ♪ miranda: ♪ i got red dirt stains on my boots and jeans. ♪ ♪ calloused fingers from my guitar strings. ♪ ♪ wild like the wind in the tall pine trees. ♪ ♪ i got roots and i got wings. ♪ ♪ with rollover data, the data you don't use this month rolls over to the next month. and i don't have to do anything? not a thing, mobile share value customers get it automatically. it's how we show appreciation. you know i really appreciate that you appreciate me as a customer. and we appreciate how much you appreciate us appreciating our customers. and i appreciate that you appreciate that. and i appreciate you appreciating that. i appreciate that. aaaahhhh. introducing at&t rollover data. the data you don't use rolls over to the next month. all on the network with the nation's strongest lte signal. >> reporter: july 24, 2014. after two agonizing stalemates, this time things were different. as seth techel walked into the courtroom and sat down his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family, and certainly not at todd, his former father- in-law. this is the young guy you used to clap on the back and say, "i love you." >> yep. "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now, the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one -- we the jury find the defendant seth andrew techel guilty of murder in the first degree. signed by the head juror. count two -- non-consenual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin', not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26, and then, there's seth from may 26 on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent-up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. we know this family. i know it's not doug and lorraine's fault. it's not their family's fault that any of this happened. todd searched out doug. only three years before, they were all celebrating their kids' wedding together. doug and lorraine still support their son and say he didn't do what he's now convicted of doing. do you have a whisper of doubt, either of you? >> no, sir. >> none whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment, too. >> i started cryin'. it wasn't tears of sorrow, it was tears of joy. they had finally gotten this s.o.b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're gonna have last word on brian tate. this is an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held in september 2014. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley, lisa's sister, walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister, and i no longer love you. >> reporter: and then the judge handed down the sentence. life in prison, with no possibility of parole. when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. what are the figures in it, todd? >> the first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook," movie and it's -- we've always said, "if you're a bird, i'm a bird." you know, i mean, whatev -- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, this is part of lisa now." >> 10 seconds! [ laughter ] >> ♪ now promenade your sweet, little maid ♪ ♪ake that girl and give 'er a whirl ♪ all right! give yourselves a big hand now! [ cheers and applause ] [ dramatic music plays ] >> johnny! >> johnny, i thought they fired you. >> well, they did, pete. but i gotta ask one last favor. can you call this? >>
go get him now! >> reporter: a neighbor with a gun and a grudge. >> i thought, "they better get to him before i do." >> reporter: but some said this couple was having trouble. that seth had a secret. >> did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: others said the real murderer was someone else, right under cops' noses. >> here's a legitimate suspect that should have been investigated. >> reporter: a case unfolding on camera, one that would test three juries, shatter two families. >> just like somebody hit me in the stomach. >> reporter: and take one final twist -- >> that was her biggest secret. >> i'm lester holt and this is "dateline." here's dennis murphy with "before dawn." >> reporter: the cornfields of iowa are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yep, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. >> once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. >> bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children, all the while he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters. this time, he was getting lots of help from lisa. she was the twins' default babysitter. >> she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> they had a very close relationship? >> uh-huh. very. i would get into bed with her. we'd watch old episodes of "the golden girls." >> that's a sweet relationship. >> yeah. and she always says that i was dorothy, because i'm such a grouch all the time. but -- yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. i was the one that they had to pass the test with. >> reporter: the boyfriend who passed with flying colors was a kid named seth techel. he came from a longtime local family. his grandfather had been the umpteen terms mayor of ottumwa. mom was a social worker. dad owned a local bowling alley. and the bowling alley was where seth, as a young teen, began noticing lisa. his dad was her high-school coach and seth bowled almost -- but not quite -- as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend-girlfriend and that was fine with both their families. >> so you liked this young girl? >> oh, a lot. yeah. >> she was a part of our family. >> yeah. >> reporter: the techels were a church-going family and seth's mom lorraine remembers how the boy's compassion for others shone on a relief mission to mississippi after hurricane katrina. >> he just stood and talked to these folks for hours and hours. and they just became very good friends. and i have a lot of memories like that of seth. >> helping people? >> yup. >> reporter: and lisa wanted to help people, too. she followed her father into law enforcement. first as a reserve deputy in todd's sheriff's department and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop, because i didn't wanna have to worry about, you know, her inefficiencies maybe endangering her life. >> reporter: after years of hearing patrons at the bowling alley joke about when the two of them were going to get married, seth and lisa made the inevitable official. >> how do you find out they're gonna get hitched? >> seth actually came to our house and met with us and asked us our permission to marry lisa. >> old school? >> old school. >> reporter: after dating for seven-years, seth and lisa got married in october, 2011. she was 22; he was 21. >> i just told him that no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> reporter: lisa's sister -- another elvis namesake -- presley -- got much more than a brother-in-law with seth. >> he was my best friend. he was just kind of that other person that i could always go to. >> he called me, "dad." we told each other we loved each other. we hugged every time we left each other. i mean i felt as close to him as i did my son. >> reporter: for lisa it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> so how did lisa put up with you guys? >> she was kind of interested in the same things that all of us were. like, she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> better than seth. >> it sounds like you guys all would have been happy if she were your girlfriend. >> seth was lucky. >> reporter: lucky, for sure. but seth knew it was time to settle down and get a real job. like lisa he was drawn to uniformed service. he'd signed on as a volunteer firefighter and drew a paycheck as a security guard. but his father-in-law todd was helping him get a higher rung on the ladder with a soon-to-start job as a jailer for the sheriff's. >> reporter: they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> reporter: a new job, a young marriage and now more changes for seth. he was going to be a father. they'd picked a name for the unborn girl -- zoey maria. in may 2012 they were halfway through the pregnancy. seth and lisa, a baby on the way, were starting out their married life in this humble little trailer. it was a gift from his dad, perched on just a beautiful piece of property. it was a kind of starter home while they saved some money for the future. the only apparent cloud in the picture was an escalating feud with an across the fence neighbor here. there was bad blood. it happened at 5:00 in the morning. a sudden, horrifying sound that shattered two young lives. >> wapello county 911. what's your emergency? >> reporter: saturday, may 26, 2012. memorial day weekend. >> she's not breathing. >> does she have any medical problems? >> no, she's been shot. >> reporter: a shotgun blast had ended all the plans of mr. and mrs. seth techel. newlywed, mom-to-be, and now -- out of the blue -- victim of a violent attack. who would want to hurt lisa? when we return -- deputies race to the scene, where the shooter could be lurking anywhere. >> you didn't know if somebody coulda winged a shot at you? >> yeah, that was possible the whole time. applebee's let the fans put their favorite dishes on the famous 2 for $20 menu. i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. morning hank.icks qlearquil what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. ♪ [music] jackie's heart attack didn't come with a warning. today her doctor has her on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before you begin an aspirin regimen. so did you hear the new iphone is out? i'm getting one! sprint is offering this exclusive new plan with unlimited data. the plan is only $50 a month! $50? unlimited iphone! [glass shattering] so should we eat? the new sprint simply unlimited plan, exclusively for iphone 6. unlimited data, talk and text for just $50 a month. switch to sprint and we'll buy out your contract. it's the best value in wireless. reporter: it was the end of a long overnight shift for sheriff's deputy marty wonderlin -- the only deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday morning, marty relaxed and turned up the music in his cruiser. >> the ragged end of the shift for you, huh? >> yeah. i'm takin' my last little loop around the county and gonna watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 am, when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. >> i have now been advised this lady's just been shot. >> is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing ninety, marty raced to the house in under 10 minutes. he slowed along the rise of the gravel country road and stopped in the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just-- bent over, you know? >> what's he doing? >> sounds like he's crying. just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch considered him a friend, knew his wife lisa too, and her father todd was a respected fellow deputy. the unfolding tragedy had just become very personal. >> deputy, how do you set your brain in compartments, where you gotta be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> you didn't know if somebody coulda winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene -- the possibility of a live shooter still on the grounds -- marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn'ta done that. i wish i would -- >> why do you say that? >> well, 'cause i saw a lotta things that morning and now because of me, because of askin' him to, you know, come out there, he's gonna have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep but his cell phone was plugged in next to the bed always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter -- her best friend -- needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 mile an hour, you know? i'm an e.r. nurse. i'm thinkin' -- >> you're sort of in nurse mode there too? >> yeah. i was - i -- i'm thinkin', "well, you know, maybe if i get there fast enough, that --" >> minutes matter? >> there'll be something i can do. >> reporter: todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh, my god, oh, my god, oh, my god." i just remember that's all i could think and say is, "oh, my god, oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was gettin', like, a defibullator ready. it felt like forever. you know, and i'm askin' him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone along with her unborn daughter. lisa marie techel was just 23 years-old. >> i ran in there and -- you could tell that she was gone. >> so you went into the bedroom? you saw her? did you tend to her? >> yeah. i hold her -- i held her hand and -- i rubbed her belly and -- and i just said, "my lisa, my lisa." >> todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her layin' there. and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe -- but i don't even remember doin' that. "what happened?" >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> gotta start workin' it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ] go get him. go get him. now. >> reporter: coming up who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. >> reporter: when dateline continues. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. [ siri] hello. wh[cortana] name? hello siri. i'm cortana. we've already met. i'm sorry. i don't remember. that's ok. i can remember lots of things. like your favorite kinds of restaurants. i cannot remember that. i can remember appointments and help you get there on time. or that. or remember favorite news topics. or that either. siri, what can you remember? i remember when i was the only phone that talked. ♪ looking for one of these? yoplait. smooth, creamy, and craved by the whole family. reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside -- shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. >> he punched his truck, and i said, "don't do that, seth, you know, let me see your hand. >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> was just bad. i mean, it-- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. >> how's that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's [bleep] laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the [bleep] shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the f--- did this. >> there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. >> we'll figure it out, brother. >> i can't [bleep] tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out . and already had a suspect. >> go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire. a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. >> this is this culmination of bad blood's been goin' on for a month's time or more now? >> uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yep. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. >> okay. >> and i'll tell - - i just - - they're good people. they really are. >> now this guy, brian tate, does he know that you're the father-in-law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to effect maybe what he does or doesn't do. >> and he thinks that's the source of his trouble? >> right. >> those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of -- a bell goes off like, "terrorism's kind of-- a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i s -- i notice -- a shotgun layin' on the ground, you know? and i'm like goin'-- that makes me feel a little -- >> does that make you a little twitchy? yeah. yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out okay, if you go out there, be careful. tate might be 1096 which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker, used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle wtever. and uhm but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism - the "terrorism" - was getting worse. todd responded again. this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. oh, me too. but no i'm good i know where i'm headed. how about music? nah i don't really feel like- ♪ just the two of us ♪ we can make it if we-- what a fun drive. we always have so much fun. remember that one time we- okay. sure you loved your old iphone. but you'll love your free new iphone you trade it for even more. you are loved a lot. and in so many ways. and when you're wrapped in the comfort of pampers swaddlers with blanket-like softness and up to 12 hours of protection, all you feel is love. wishing you love, sleep and play. pampers. while a body in motion tends to stay in motion. staying active can ease arthritis symptoms but if you have arthritis, this can be difficult. prescription celebrex can help relieve arthritis pain, so your body can stay in motion. because just one 200mg celebrex a day can provide 24 hour relief for many with arthritis pain and inflammation. plus, in clinical studies, celebrex is proven to improve daily physical function so moving is easier. and it's not a narcotic. you and your doctor should balance the benefits with the risks. all prescription nsaids, like celebrex, ibuprofen, naproxen and meloxicam have the same cardiovascular warning. they all may increase the chance of heart attack or stroke, which can lead to death. this chance increases if you have heart disease or risk factors such as high blood pressure or when nsaids are taken for long periods. nsaids, like celebrex, increase the chance of serious skin or allergic reactions, or stomach and intestine problems, such as bleeding and ulcers, which can occur without warning and may cause death. patients also taking aspirin and the elderly are at increased risk for stomach bleeding and ulcers. don't take celebrex if you have bleeding in the stomach or intestine, or had an asthma attack, hives, other allergies to aspirin, nsaids or sulfonamides. get help right away if you have swelling of the face or throat, or trouble breathing. tell your doctor your medical history. and ask your doctor about celebrex. for a body in motion. and now celebrex may be available for as little as $4 a month. terms and conditions apply. to learn more, go to celebrex.com. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was 5 months pregnant. >> reporter: lisa's murder was the first in the farm town in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. >> todd and i began the same year at the sheriff's office together. i'd watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> so, whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriff's office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators were ready to confront the neighbor. >> so, the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car while deputy phillips and a partner drew line-of-fire detail, approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my -- my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming. everyone was poised for battle. everyone but, it turned out, brian tate. he wasn't armed or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so, the cops turned on a recorder and started asking questions. >> so, you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up until 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15 hour sleep alibi. though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this [ bleep ] that happened. but i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line. vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11 days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you -- you'd sit outside here. >> at night? >> at night. yeah. when's the last time you did that? >> oh. it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm, quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me so i'm kinda taking a different approach to life right now. >> i mean, when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. >> so, what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for later that day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i -- i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so, he went downtown and instructed his parents -- no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator and the tone of the investigation was about to change. coming up -- deputies learn that seth may be hiding something. >> i told 'em that seth had a trac phone. >> some kind of secret phone, huh? >> yeah. >> reporter: when "dateline" continues. us 2 for $20 menu. why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. dowlower... that's more like it! petsmart's prices on your favorite food brands just got lower! shop a wide assortment of food and save $7 on select nutro® natural choice® dry dog food, and save $20 when you buy 2 bags! petsmart®. reporter: todd and amy returned home. destroyed. and the longest day of their lives, wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that -- that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight-hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got underway. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. >> his story begins somewhere around 5:00 am. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't [ bleep ] protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete [ bleep ] jackass to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy-ass neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning: >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> -- to shoot a cop." and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay? >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. >> what was the story you told 'em, colton? >> i told 'em that seth had a trac phone. >> some kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair but he could walk at any moment. coming up -- more about seth's secret phone. seems it wasn't just for talking. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes and better than ever, starting at just $9.99. say yes to bowl after never ending bowl of your favorite pasta and more yes to savory new sauces like velvety roasted mushroom alfredo and spicy three meat, plus toppings like crispy chicken fritta. never ending pasta bowl, your favorite pasta, garden salad, and fresh baked breadsticks. it's all unlimited starting at $9.99, but just for a limited time. only at olive garden, we're all family here. enjoy unlimited soup, salad and breadsticks lunch just $6.99. and we're new to the pacific northwest. the rain, the mud -- babam! it's there. the outside comes in. it's kinda nasty so you start the towel-mop shuffle. where are you sun?! [ doorbell rings ] oh, wow, it's a swiffer wetjet. this puts my towel mopping to shame. whoa! ewww. sunshine is overrated, now we can get messy. [ laughs ] now we can get messy. could save you fifteen percent or more on car insurance. everybody knows that. well, did you know you that former pro football player ickey woods will celebrate almost anything? unh-uh. number 44... whoooo! forty-four, that's me! get some cold cuts... get some cold cuts... get some cold cuts! whooo! gimme some! geico. fifteen minutes could save you fifteen percent or more on car insurance. whoo! forty-four ladies, that's me! whoo...gonna get some cold cuts today! and this ithe iphone 6 plus. they come with a thing called health, so they can help you track a lot of stuff. like today, i walked 3.8 miles. well, i ran 4.2 miles. well, i climbed 11 flights of stairs. well, i drank a smoothie that had 362 calories in it. well, i had a funnel cake that had 1230 calories in it. ♪ you know that's not good, right? it was good. it was delicious.♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ reporter: seth techel had gone downtown voluntarily but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room, seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> and this person had told him a story about a girl named rachel. >> reporter: but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair -- then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland. but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, hey, how was your day type of thing. >> would it be considered sexting? >> no. no. none of that. >> "what are you wearing?" >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking. you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no. everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes -- or? >> i never had sexual, sex with her. no, nothing oral, nothing like that. uh -- i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop -- >> they -- >> -- they didn't come out. >> -- didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so, thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was -- that was that. >> reporter: meanwhile, both dci agents, birmingham and thomas, had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special trac phone as a steamy hotline. >> i know they were exchanging photos. >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton know about you texting rachel? >> uh-huh. >> did you tell him about it? >> yeah. >> this is an on-going investigation. and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night. today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on for close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> be confrontational, because the clock is ticking. and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us -- you're responsible for killing your wife. >> no, no, i'm not. no, i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel, i would get a divorce. i would not [ bleep ] kill my wife over something that small. you know what? right now, i guess i don't give a [ bleep ] what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> thank you, sir. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex. but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. >> you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure in some regards. >> why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100 percent certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at -- at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and maybe a crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? coming up -- one piece of the puzzle falls into place. >> boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. >> this has gotta be more than your brain can absorb. >> definitely. >> reporter: when "dateline" continues. health can change in a minute. so cvs health is changing healthcare. making it more accessible and affordable, with over 900 locations for walk-in medical care. and more on the way. minuteclinic. another innovation from cvs health. because health is everything. do you have something for pain? i have bayer aspirin. i'm not having a heart attack, it's my back. i mean bayer back & body. it works great for pain. bayer back & body provides effective relief for your tough pain. better? yeah...thanks for the tip! i read most of the book.. having a baby isn't gonna be that hard. you didn't read the book. i read some of the book. it's all about being prepared. proper nutrition... keeping the romance alive. level 7! and setting a good example. daddy's trying. we are so ready for this. life can surprise you. so can an allstate agent. from savings on a new car, to discounts on a great car seat. the good hands are doing more than ever before. that there's the guy who gets his salsa from new york city. new york city?! [ male announcer ] only pace has that big, bold kick. anything else just ain't right. pace. grab the southwest by the bottle. okay patrick, one more stop. anything else just ain't right. lets go base, shark, blitz. base, shark, blitz, break! when the game's on the line... okay, this is for the game. the nfl trusts duracell quantum to power their game day communication. flag nineteen, set hut! abort! abort! he's keeping it. hut! duracell quantum. lasts up to 35% longer than the competition. lisa pregnant with her first child has been killed by a shotgun blast. investigators have quickly zeroed in on two suspects. lisa's husband who may have been involved with another woman, and a neighbor who had an ongoing beef with the couple. starting with a bombshell arrest and leading up to an explosive secret revealed from beyond the grave. here again, dennis murphy. reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. >> one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer was not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." >> we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode -- and -- tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon -- and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa, and had just moved out. we showed lucas this photograph, taken of seth at his home. >> if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes. it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa -- but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. >> reporter: too long into this sunday morning search, over here by this big old tree, what do you hear? >> "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20-yards from the back door of the trailer. >> reporter: that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives: was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's "work" friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here -- someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: sounds like they were making out rather than having sex. >> yes, that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> reporter: would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect -- and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know? did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. >> reporter: so you only had one suspect at this point. >> yeah. one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. >> reporter: your fellow officers are there as they would be, you know, they, you know, want to show respect. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained -- still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. >> i said, "is this --a personal visit or a professional -- >> reporter: this condolences or somethin' else, huh? >> and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we -- we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders; he arrested his friend seth techel. a fellow deputy put the cuffs on him -- they were lisa's cuffs, the ones she'd used as a reserve deputy. >> reporter: this has gotta be just -- more than your brain can absorb. >> yeah. >> little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sherifff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife.3 f2 a continuación, seth techels even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. you want it ... until boom, it's bedtime! your mattress is a battleground of thwarted desire. enter the sleep number bed. designed to let couples sleep together in individualized comfort. he's the softy. his sleep number setting is 35. you're the rock, at 60. and snoring? sleep number's even got an adjustment for that. you can only find sleep number at a sleep number store. right now, save $400 on our most popular mattress. know better sleep with sleep number. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. .... any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now he'd returned to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pall bearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me?" i was so proud. >> i should've been able to be there and watch her become a mom. she was just a joy. >> mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. >> the coroner would think it was heart. >> yes. >> what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown, from the state's attorney general's office, worried that a jury might think the deranged, deceased neighbor did it. their plan had been to call tate as a witness. >> on the theory that the -- the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> february 2013, can you see yourself going into the courthouse? >> yeah. i remember. >> what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in-laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first-degree murder and nonconsensual termination of a pregnan pregnancy. >> what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> how were you gonna mess with him? >> fill five gallon buckets full of dog manure. and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law and the state agent who interviewed him the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dash-cam video, it became evidence for the prosecution. >> we feed the squirrels, birds birds, and deer. >> we were hopeful that the injury woujury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man, certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland, the other woman, to show up and tell her story. >> did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december 2011, which was two months after seth got married. >> it became more sexual. asking me to send pictures. or, i don't know, just showing off my body, i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common. and that he had tried working things out with lisa and they just weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th, when he learned that you were communicating with brandon, he said what? >> just give me two more weeks >> did you ask him what he meant, just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element, sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him? >> no. >> never had your clothes off? >> no, sir. >> and you kissed a few times? >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel? >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. >> you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter and jelly sandwich in a baggie left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. coming up -- in the jury room, deliberations and drama. >> he started pounding on the door saying that he wanted out of there. and we were in tears. >> reporter: when dateline continues. of what they're looking for. somebody who has sensitivity, they want relief from their sensitivity pain, but they also want the other things that are available in toothpaste. new sensodyne complete protection is designed specifically for sensitivity sufferers, but then, on the other side of the coin, it's also delivering on the other attributes that patients want out of a sensitivity toothpaste, delivering a complete package. i think dentists are going to want to recommend sensodyne complete protection. it's going to be a breath of fresh air for them. sensodyne complete protection. take and... exhale.in... aflac! and a gentle wavelike motion... aahhh- ahhhhhh. liberate your spine, ahhh-ahhhhhh aflac! and reach, toes blossoming... not that great at yoga. yeah, but when i slipped a disk he paid my claim in just four days. ahh! four days? yep. find out how fast aflac can pay you, at aflac.com. applebee's let the fans put thefamous 2 for $20 menu.the why did i put the bourbon street chicken and shrimp on applebee's 2 for $20 menu? because it's the most beautiful thing i've ever seen. hi. oh, happy birthday. applebee's. where fans know best. (carter) making a mess.alent for but it's ok...our new kitchen is zoe proof. (announcer) the time saving frigidaire gallery smudgeproof appliances resist fingerprints. and clean easily. so now you have more time to savor all those "sweet" family moments. frigidaire gallery. our time-saving legend continues. find more of the brands you love at kohl's grand opening sale. find new styles from nike for girls and boys great savings on athletic shoes for the family. levi's for him - buy one get one half off! the latest looks from rock & republic. cute playwear from carter's. and introducing the new kuerig 2.0 brewer for cup or carafe. save even more when you shop late friday and early saturday. plus, everyone gets kohl's cash starting friday find your yes. kohl's. reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. >> they stay out and they stay out and they say out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and 3-full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is hereby granted. >> reporter: the judge declared a mistrial because of a hung jury. >> hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to re-try the case. the vote had been 10 to 2 for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven month ts --s later, october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells the daily treks to court. lives disrupted the new courtoom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," vs. seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his -- his own smiling face saying, "miss you bella." >> um-huh. >> is that a term of endearment that he called you, his bella? >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck." i love you. at 10:51 p.m. on may 24th of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her; i felt like she destroyed my sister's marriage and her life. >> rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth, but i think she's kinda been a victim as well. >> he's manic, he's up all the time. he could become volatile and agitated. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> the judge wasn't ready to give up. he told the jurors to keep trying. the emotions in the courtroom were raw. >> presley and i weren't crying, but you could hear us sniffling a little. >> i do not desire a jury to be influenced by the public. >> now it was the prosecutors turn to see. >> the defense is making a speech about the caldwell family to try to influence the jury, which i thought was ludicrous. i'll take this. >> to stand up here and suggest that anyone in the courtroom is making an attempt to intenti intentionally influence the jury is nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here." >> reporter: for more than a minute glaring, burning a hole in seth's back. if looks could kill -- >> there's just kind of an urge to move forward. >> to jump the rail? >> yeah. god please don't make me do that. just let me stand. >> what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. a mistrial is declared. unbelieveable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction -- this time 9 to 3 -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like, he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings but a brand-new defense team. >> i heard it about a week before the trial and it just like somebody hit me in the stomach. >> reporter: coming up the defense comes out swinging. >> we chose to focus on the sloppy work done by the law enforcement. there was no dna, fingerprint, confession. watch: when hair loses protein, it splits and fails the needle test. but with pantene, the advanced pro-v formula helps prevent protein loss and stop split ends before they start. so your hair passes the test with ease. put pantene to the test. for hair so healthy you shine. well, not that kind of fresh. on the freshness of our chicken. but i can guarantee the freshness of our chicken because we go beyond what the usda requires... with extra inspections in american family owned farms, refrigerated trucks that deliver daily and everywhere in between. that's what it takes to bring your family a fresh tasting chicken. perdue. we believe in a better chicken. dos familias, 2 juicios. to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in -- in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement, there was absolutely no dna, fingerprint, confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? >> no, we forgot, or we didn't do it. >> whoops. >> whoops. >> reporter: the new defense team had a new story to tell. it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the bogeyman of the first two trials, brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> we were going to stay on our path, doing that, we made the decision to drop out the brian tate video interviews that we'd put in in the first two cases. >> reporter: the caldwells and techels had been put through the ringer for more than two years. their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person. >> did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing of you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july, 2014, -- for the third time, the state of iowa vs. seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three-hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, forever? >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well we talked, i told her i wasn't happy, she got mad, then sad, then i slept on the couch, so hello mrs. resuscitator. >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mister resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had, and that included explosive new evidence. this time, it was about lisa. coming up -- >> you found out the story that there was this guy, co-worker? >> yeah. >> was there another man in lisa's life, when "dateline" continues. depression, or unusual changes in mood or behavior. or swelling, trouble breathing, rash, hives, blisters, changes in eyesight including blurry vision, muscle pain with fever, tired feeling, or skin sores from diabetes. common side effects are dizziness, sleepiness, weight gain and swelling of hands, legs and feet. don't drink alcohol while taking lyrica. don't drive or use machinery until you know how lyrica affects you. those who have had a drug or alcohol problem may be more likely to misuse lyrica. having reduced pain is great, and i'm grateful for it. ask your doctor about lyrica and visit lyrica.com to learn about our $25 co-pay offer. ♪ ♪ ♪ ♪ ♪ we have a saying... mi coffee es su coffee. our way of inviting you to share what's ours. so between september 16th and the 29th, we want to treat you to a rich, smooth mccafé coffee for free. why would we do that? when you have something this delicious, you just have to share it. ...on the casa. ♪ coube a breakthrough wayrip to get immediate and long lasting sensitivity relief instead of sensitivity toothpaste? find out, with new crest sensi-stop strips. just apply to the gumline of sensitive teeth for a quick 10 minutes. the special ingredient forms a lasting barrier that provides immediate relief and up to one month of protection. crest sensi-stop strips. a whole new way to treat sensitivity. that's 1 strip. 10 minutes. and up to 1 month of protection. satisfaction guaranteed. life opens up when you relieve sensitivity. ♪ here's a good one seattle... what did geico say the mariner? we could save you a boatload! ♪ foghorn sounds loudly ♪ what's seattle's favorite noise? the puget sound! ♪ foghorn sounds loudly ♪ all right, never mind doesn't matter. this is a classic. what does an alien seamstress sew with? a space needle! ♪ foghorn sounds loudly continuously ♪ oh come off it captain! geico. fifteen minutes could save you fifteen percent or more on car insurance. reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. go get him, now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel -- offered as seth's motive for murder in earlier trials -- was also minimized this time. >> good afternoon miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. >> tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man, right? >> correct. >> and the only time you'd actually seen him in person in your whole entire life was outside of work four or five times? >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the i's have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it? >> yeah, exactly. we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel? >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we, we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. >> you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. lisa's lover was a married man, a father of four. >> and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes, i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes, at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse, correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter has a lover was the cruellest blow yet. >> the first emotion i had is, "why? why, lisa," you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all? >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26th, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. >> cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? coming up --ed to and just about everyone else are in for a surprise. introducing vicks qlearquil allergy morning hank. what a day, huh? hey! morning hank. for people who don't have allergies every day, just on allergy days. (sneeze) new qlearquil. the powerfully effective, take it only when you need it, so you can be you again, allergy medicine. boo! haha. all right, see you buddy! and introducing qlearquil nighttime, the new allergy medicine for night. qlearquil, powerful sinus and allergy medicine from the makers of vicks nyquil and dayquil. this is holly. her long day of outdoor adventure starts with knee pain. and a choice. take 6 tylenol in a day or just 2 aleve for all day relief. onward! applebee's let the fans put thefamous 2 for $20 menu.the i put the wonton tacos on applebee's 2 for $20 menu because i love them. and, i am old enough to know what love is! we're still talking about tacos... right? applebee's. where fans know best. but do you know what's ine your skincare?- neutrogena naturals. a line of nutrient-rich skincare with pure, naturally derived ingredients, carefully chosen and clinically proven to cleanse, purify and moisturize... and you'll never find any harsh chemical sulfates, parabens or unnecessary additives. healthy skin-starts from within. neutrogena naturals. learn more at neutrogenanaturals.com. ♪ only sears brings you more selection with all top ten appliance brands. like kenmore, the most awarded brand in the industry. ♪ and when life happens, more peace of mind with service that's number one nationwide. ♪ that's more performance, from the #1 appliance store. sears. ♪ this time things were different. as seth techel walked into the courtroom and sat down, his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family. and certainly not at todd, his former father-in-law. >> this is the young guy you used to clap on the back and say, "i love you." >> "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one, we the jury find the defendant seth andrew techel guilty of murder in the first degree. count the, nonconsensual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. >> reporter: and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin. not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26th, and then, there's seth from may 26th on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. >> we know this family. i know it's not doug and lorraine's fault. it's not their family's fault -- that any of this happened. >> reporter: todd searched out doug. only three years before, they were all celebrating their kids' wedding together. >> reporter: doug and lorraine still support their son and say he didn't do what he's now convicted of doing. >> reporter: do you have a whisper of doubt, either of you? >> no, sir. >> none. whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment too. >> i started cryin'. it wasn't tears of sorrow. it was tears of joy. they had finally gotten this s-o-b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're going to have the last word on brian tate. this was an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held on september 10th. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley -- lisa's sister -- walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister and i no longer love you. >> reporter: and then the judge handed down the sentence. >> thank you, ms. caldwell. >> reporter: life in prison with no possibility of parole. ♪ >> reporter: when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. >> what are the figures in it, todd? >> reporter: first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook" movie and it's -- we've always said, if you're a bird, i'm a bird. you know, i mean, whatev-- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, this is part of lisa now." >> that's all for this edition of "dateline." we'll see you next friday at 9:00, 8:00 central. tomorrow music for change the global citizen festival, the concert headlined by jay-z and featuring carrie underwood and no doubt, plus lots of surprises all celebrating citizens who care. that's tomorrow at 9:00, 8:00 central. i'm lester holt. >> now at 11:00, the suspect in hannah graham's disappearance es courted. chaos in the skies. thousands of flits
a husband's lust -- >> did he tell you, "she sent me some topless pictures?" >> yes. >> did you see them? >> yes. >> reporter: then, a wife's double life exposed. >> that was her biggest secret. a case that would test three juries and shatter two families. before uncovering one terrifying truth -- >> reporter: this has gotta be just more than your brain can absorb. >> definitely. >> it's heartbreaking. >> just like somebody hit me in the stomach. >> reporter: the cornfields of iowa. ♪ are a far piece from memphis. but it was here, in ottumwa, iowa, a baby girl was named after a princess. lisa marie. yup, that one. >> as a kid, i was pretty big into elvis. i knew that my first daughter was gonna be lisa marie because of elvis, of course. >> reporter: just as todd caldwell hoped, his little lisa lived up to her big name. >> she was just the life of the party. once she started talking, she hadn't shut up. >> reporter: they're divorced now but tracy and todd caldwell watched their girl grow up all but unstoppable. a vivacious, winning teen. bowling, todd, we're not just talking recreational saturday night now and then? >> no, we're talkin' about a state champion bowler. anything she did, she had to be the best at it. >> lisa, look over here. >> reporter: lisa was a teenager when her parents divorced. todd remained an active father to lisa and his three other children. all the while, he was working a stressful and dangerous job as a deputy in the wapello county sheriff's department. he found comfort in several ways. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters this time, he was getting lots of help from lisa. she was the twins' default babysitter. she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> reporter: you had a very close relationship? >> uh-huh, very. i would get into bed with her. we'd watch old episodes of the golden girls. [ laughter ] >> reporter: that's a sweet relationship. >> yeah, and she always says that i was dorothy because i'm such a grouch all the time. [ laughter ] but yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. [ laughter ] i was the one that they had to pass the test with. the boyfriend who passed with flying colors was seth. he came from a long time local family. his grandfather was the mayor. the dad owned a local bowling alley. the bowling alley was where seth as a young teen began noticing lisa. his dad was her high school coach and seth bold almost but not quite as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend/girlfriend and that was fine with both families. >> you liked this young girl? >> a lot. >> she was a part of our family. >> they were a church going family and seth's mom remembers how the compassion shown on a relief mission to mississippi after hurricane katrina. >> he just would talk to the folks for hours and hours. they became very good friends. i have a lot of memories like that of seth. >> helping people. >> yeah. she followed her father into law enforcement and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop because i didn't want to have to worry about her inefficiencies maybe endangering her life. >> after years of hearing patrons at the bowling alley when they would get married, they made the inevitable official. >> how did you find out they were getting hitched? >> seth came to our house and met with us and asked us our permission to marry lisa. old school. >> old school. >> after dating for seven years, seth and lisa got married in october 2011. she was 22, he was 21. >> i just told him that, no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> she got much more than a brother-in-law with seth. >> he was my best friend and he was that other person that i could always go to. >> he called me dad. we told each other we loved each other. we hugged every time we left each other. i felt as close to him as i did my son. >> for lisa, it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> how did she put up with you guys? >> she was interested in the same things that all of us were. she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> sounds like you would have been happy if she were your girlfriend? >> seth was lucky. >> lucky for sure. but seth knew it was time to settle down and get a real job. like lisa, he was draund drawn to service. he drew a paycheck as a security guard. his father-in-law todd was helping him get a higher rung in the ladder. the soon to start job as a jailer for the sheriffs. >> >> they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> now more changes for seth. he was going to be a father. they picked a name for the unborn girl, zoe maria. in may 2012, they were halfway through the pregnancy. >> seth and lisa, a baby on the way were starting out their married life in this humble little trailer. it was a gift from his dad purchased on a beautiful piece of property. a starter home to save money for the future. the only apparent cloud in the with an across the fence neighbor. a sudden horrifying sound that shattered two young lives. >> 911. >> saturday, may 26, 2012, memorial day weekend. >> not breathing. >> does she have any medical problems? >> she's been shot. >> a shotgun blast that ended all the plans of mr. and mrs. seth. deputies raced to the scene where the shooter could be lurking anywhere. >> even though somebody could have winged a shot at you. >> that was possible the whole time. we did it charlie. at&t's network now has the nation's strongest lte signal. let's go tell everybody. we're doing things like putting lte radio's at the top of our towers. to maximize power. and give you the strong signal you deserve. that's awesome! isn't is awesome?! so ya'll optimizied it? we optimized it! people of earth... oh boy... ...america's strongest lte signal is here! ♪ by 1914 the dodge brothers quit the ford motor company and set out on their own. they believed in more, than the assembly line. they believed driving was a holy endeavor. a hundred years later, the dodge brothers spirit lives on. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. (kids laughing) you know i tried one of those bargain paper towels but i had to use so many sheets per spill the roll just disappeared. i knew i should've bought bounty bounty is 2x more absorbent and strong when wet. just look how much longer bounty lasts versus one of those bargain brand towels. and that's a good deal. bounty. the long lasting picker upper and now try new bounty nfl prints. available at walmart. when you ache and haven't slept... you're not you. tylenol® pm relieves pain and helps you fall fast asleep and stay asleep. we give you a better night. you're a better you all day. tylenol®. introducing light & fit protein shakes the new way to help make temptations shrink away on the go. a deliciously fresh and satisfying taste with 12 grams of protein 5 grams of fiber and 0% fat. new light & fit protein shakes. taste the power of satisfaction. ♪ dannon ♪ long overnight shift for sheriff's deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday >> reporter: it's the ragged end of the shift for you, huh? >> yeah, i'm taking my last little loop around the county and going to watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 a.m. when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. i have now been advised this lady's just been shot. >> reporter: is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing 90, marty raced to the house in under ten minutes. he slowed along the rise of the gravel country road and stopped at the end of the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> reporter: here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just bent over, you know? >> reporter: what's he doing? >> sounds like he's crying, just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch, considered him a friend, knew his wife lisa too. and her father, todd, was a respected, fellow deputy. the unfolding tragedy had just become very personal. >> reporter: deputy, how do you set your brain in compartments, where you got to be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> reporter: were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> reporter: you didn't know if somebody could have winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene, the possibility of a live shooter still on the grounds, marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her, but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." >> call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn't have done that. i wish i would -- >> reporter: why do you say that? >> well, because i saw a lot of things that morning and now because of me, because of asking him to, you know, come out there, he's going to have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep, but his cell phone was plugged in next to the bed, always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter, her best friend, needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 miles per hour, you know? i'm an e.r. nurse. i'm thinking -- >> reporter: you're sort of in nurse mode there too? >> yeah, i'm thinking, "well, you know, maybe if i get there fast enough -- >> minutes matter. >> there will be something i could do. todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh my god. oh my god, oh, my god." i just remember that's all i could think and say is, "oh, my god. oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was getting, like, a defibrillator ready. it felt like forever. you know, and i'm asking him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone. along with her unborn daughter. lisa marie techel was just 23 years old. >> i ran in there and you could tell that she was gone. >> reporter: so you went into the bedroom? you saw her? did you tend to her? >> yeah, i held her hand and i rubbed her belly and i just said, "my -- my lisa, my lisa." >> reporter: todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her laying there and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe, but i don't even remember doing that. >> what happened? >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> got to start working it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ]. go get him. go get him, now. >> reporter: who was todd caldwell talking about? turns out there was someone in seth and lisa's life who had everybody worried. >> things were escalating. they were fearful. i was fearful. welcome to the most social car we've ever designed. the all-new nissan murano. nissan. innovation that excites. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. we live in a pick and choose world. choose, choose, choose. but at bedtime? ...why settle for this? enter sleep number, and the ultimate sleep number event, going on now. sleepiq technology tells you how well you slept and what adjustments you can make. you like the bed soft. he's more hardcore. so your sleep goes from good to great to wow! now we can all choose amazing sleep only at a sleep number store. right now save 50% on the ultimate limited edition bed. know better sleep with sleep number. >> reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside, shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. he punched his truck, and i said, "don't do that, seth, you know, let me see your hand." >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> it was just bad. i mean, it -- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. how'd that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the -- shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the -- did this. >> reporter: there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. we'll figure it out, brother. >> i can't -- tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out and already had a suspect. >> that -- go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire, a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. this is this culmination of bad blood's been goin' on for a month's time or more now? >> right. uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yup. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. okay. >> and i'll tell -- i just -- they're good people. they really are. >> reporter: now this guy, brian tate, does he know that you're the father-in- law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to affect maybe what he does or doesn't do. >> reporter: and he thinks that's the source of his trouble? >> right. >> reporter: those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of - - a bell goes off like, "terrorism's kind of a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i notice a shotgun layin' on the ground, you know? and i'm like goin' "that makes me feel a little --" >> reporter: does that make you a little twitchy? >> yeah, yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out there and gets hurt." okay, if you go out there, be careful. tate might be 1096, which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and um -- but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism -- the terrorism -- was getting worse. todd responded again, this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well, i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. >> reporter: did you think he was a risk, that this was -- >> yeah. yeah. >> reporter: a guy who was capable of flipping out? >> i -- i did. i did. >> reporter: and now, lisa was dead, and the trailer was a crime scene. marty wonderlin, the first deputy at the scene, already knew all about brian tate and had zeroed in on him as his candidate for prime suspect. all the direction is heading across the fence to this guy whose name is brian tate. >> it is. >> reporter: and police decided it was time to pay a visit to tate. they armored up and got out their long guns, not knowing what their suspect might do. >> if you're ballsy enough to break into a house, shoot lisa and make it back out, you're ballsy enough to do just about anything. >> reporter: coming up -- cops confront their man. >> i had my rifle out, locked and loaded. each year 17 billion toilet paper tubes are thrown away in the us alone. that's enough to fill the empire state building...twice. now there's scott naturals® tube-free bath tissue. get the premium softness you need... ...without the wasteful tube. toss the tube for good with scott naturals® tube-free. (coughing) coughing disrupts everyone's life. that's why there's delsym. delsym's advanced time release formula helps silence coughs for a full 12 hours. all night... or all day. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. my tempur-pedic made me fall in love with mornings again. i love how it conforms to my body. with tempur-pedic the whole bed is comfortable. it's the best thing we ever did for ourselves. it's helping to keep us young. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. ♪ ♪ ♪ ♪ ♪ we all want to leave our mark on the world. why not make yours in the classroom? teachers open young minds and inspire future leaders. if you truly want to be great, be a great teacher, the more you know. >> reporter: on the main street of tiny agency, iowa, bad news traveled fast. a pregnant woman was dead and a gunman was on the loose. just as quickly, fear took to roost. >> the 23-year-old reserve sheriff's deputy was shot and killed in her home in the town of agency. she was five months pregnant. >> reporter: lisa's murder was the first in the farmtown in 15 years. deputy don phillips, seen here unspooling crime scene tape, had a personal stake in cracking the case. lisa's dad is one of his best friends. todd and i began the same year at the sheriff's office together. i watched lisa grow up. i just reassured him that we'll figure this out. we'll find out who did this. >> reporter: whatever's happened here is really within your family, the law enforcement family -- the county? >> correct. we're a small sheriffs office. we know everybody. we know each other's kids and extended families. >> reporter: and they also knew something about that guy next door, brian tate. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? were they another shotgun blast away from finding out? at 1:00 that afternoon, eight hours after lisa was shot, deputy phillips and a team of investigators, were ready to confront the neighbor. >> reporter: so the decision is made. "we gotta talk to brian tate." >> yes. he was definitely a person of interest that we need to go talk to. >> reporter: did you put your body armor on? >> yes, i did. >> reporter: marty wonderlin did, too. he was preparing for anything, even a shootout. >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car, while deputy phillips and a partner drew line-of-fire detail -- approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my, my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming, everyone was poised for battle, everyone but, it turned out, brian tate. he wasn't armed, or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> reporter: this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so the cops turned on a recorder and started asking questions. you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up till 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15-hour sleep alibi, though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this that happened. but, i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line, vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11-days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you, you'd sit outside here. >> at night? >> at night, yeah. when's the last time you did that? >> oh, it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me, so i'm kinda taking a different approach to life right now. >> i mean when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. so what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for that same day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so he went downtown and instructed his parents no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator, and the tone of the investigation was about to change. deputies learn that seth may be hiding something. >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. it. but the more you learn about your coverage, the more gaps you might find. like how you thought you were covered for this. [boy] check it out,mom! [prof. burke]when you're really only covered for this. or how you figured you were covered for this. when you're actually paying for this. you might be surprised at what's hiding in your coverage. talk to farmers and get smarter about your insurance. ♪ we are farmers bum-pa-dum bum-bum-bum-bum ♪ these are our cats, wolf and bear. the cat hair is so constant, it's like it's growing out of the floor. it drives me crazy. can we do something about this? (doorbell) woah. it's a swiffer sweeper. it's working like a magnet. ohhh! shed all you like, wolf. jack's heart attack didn't come with a warning. today, his doctor has him on a bayer aspirin regimen to help reduce the risk of another one. if you've had a heart attack be sure to talk to your doctor before your begin an aspirin regimen. thank you, cable for the slower internet upload speeds. for making me wait longer to share my photo albums. thank you cable, because if we never had you... ...we wouldn't know the incredible difference verizon fios makes. in customer satisfaction studies, fios is rated #1 in internet speed and reliability - 8 years running. plus, fios has the fastest wi-fi available from any provider. for a limited time, get a fios triple play online at an amazing $79.99 a month guaranteed for two years. plus, a $400 bonus with a two-year agreement hurry, deal ends february 21st. call the verizon center for customers with disabilities at 800.974.6006 tty/v >> reporter: todd and amy returned home, destroyed. and the longest day of their lives wasn't even half over. >> my remaining kids, i know they're gonna be horrified and i don't even think about myself at that point. >> reporter: but todd was thinking about the son-in-law he loved like his own boy. seth had agreed to go downtown for a formal interview, without a lawyer. by now, the county deputies had called in state agents from the dci, iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got under way. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him, sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security, but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. his story begins somewhere around 5:00 a.m. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound, coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? >> reporter: the agent asked seth what he thought had happened. >> let's go with your theory here that it was an -- intruder, right? i mean, is that fair to call -- >> that's the only thing i can think of. >> what do you think this person's intent was? >> i don't know. you'd have to be a complete -- to walk into somebody's house and shoot them. >> reporter: seth then bolstered the cops' leading theory of the crime so far -- that the neighbor, brian tate, had shot lisa. >> who was the first person that came to your mind? >> tate. my crazy neighbor who thinks that we're terrorists. >> reporter: seth went into detail about that juvenile tit-for-tat dispute with tate that started over a deer hide. he suspected tate tossed it over the fence so he said he responded in kind. >> i did the immature thing, which i admit, i threw it back on his property. >> reporter: the dispute escalated for several weeks and intensified with the incident in which tate claimed dog feces and rocks were thrown onto his property. that brought seth's father-in-law, deputy todd caldwell, out to tate's house for that official visit over tate's vandalism complaint. >> todd said that tate, the whole time, was sitting on his front porch and he was rubbing a loaded shotgun. >> reporter: seth said he knew the tenor of the visit because todd had filled him in later. his father-in-law also gave him a strong warning. >> "hey, if you're doing anything to his yard, knock it off. if your buddies are doing anything to his yard, knock it off. do not mess with this guy. he's off his rocker. he's going to be the next person -- >> sure. >> to shoot a cop." >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: the murder weapon hadn't been found so the state agent asked seth about the firearms he kept in the trailer. maybe one of those had been used. >> do you have any uh guns that are missing at your house? >> i haven't looked. >> if one of those guns is used in the homicide, we wanna know where it's at. >> don't you agree? >> oh, yeah. >> so i just ask him to write down the guns that are in his house. and he writes 'em all down. >> reporter: inevitably, the agent turned to the sharp-edged, intrusive questions that all husbands with a murdered wife have to answer. wannabe cop that he was, seth knew very well what was coming. >> we're going to ask you some tough things, okay. >> that's fine. >> okay. >> i know i'm, obviously, probably number one right now. >> let's talk about, um, people that are in your lives, and lisa's lives, um, was there any extramarital affairs? >> no. >> reporter: seth didn't hesitate. there were no other women. but out at the trailer, quite unexpectedly, someone was about to put the lie to that rosy marital picture. a good friend of seth's named colton had walked up to the crime scene tape at the drive. he told the deputies and agents there that he was looking to pick up his puppy that seth had been boarding for him. the investigators began peppering the young friend for info about seth and lisa. a detail that tumbled out surprised them. what was the story you told 'em, colton? >> i told 'em that seth had a track phone. >> reporter: so kind of a secret phone, huh? >> yeah. and he had been talkin' to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair, but he could walk at any moment. more about seth's secret phone. seems it wasn't just for talking. did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. i discovered a convenient way to moisturize every day. new nivea in-shower body lotion. first i wash... then i apply it to my wet skin. it moisturizes instantly. and lasts for more than 24 hours. then i quickly rinse off. my skin feels amazingly smooth with no sticky feel. so, i get dressed... ..and go. now i enjoy smooth skin every day. new nivea in-shower body lotion in the body lotion aisle. "...the levian family have been masters of jewelry design for centuries." this levian collection is amazing. maybe it's time to start your own. kay jewelers presents today's levian collection... featuring exclusive levian chocolate diamonds. including incredible limited edition styles like these. one more reason kay is the number-one jewelry store in america. it's... a work of art? ♪ every kiss begins with kay. ♪ to unlock the possibilities of tomorrow......"lift tab." behold the beauty of balance. crisp flakes of fiber-rich bran. answered by the perfect quantity of sun sweetened raisins. and with the sublime addition of ice-cold milk, the day begins. ♪sun'll come out, tomorrow♪ tomorrow is waiting. own it, with kellogg's® raisin bran see you at breakfast™. and delight in temptingly tart and sweet new kellogg's® raisin bran with cranberries. >> reporter: seth techel had gone downtown voluntarily, but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer, who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> reporter: and this person had told him a story about a girl named rachel. but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair, then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland, but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, "hey, how was your day type of thing." >> would it be considered sexting? >> no, no. none of that. >> what are you wearing? >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking, you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no, everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes or? >> i never had sexual -- sex with her. no, nothing oral, nothing like that. um, i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop. >> they -- >> they didn't come out. >> didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> reporter: which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was, that was that. >> reporter: meanwhile, both dci agents birmingham and thomas had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special track phone as a steamy hotline. >> i know they were exchanging photos. >> reporter: did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton, uh, know about you texting rachel? >> mm-hmm. >> did you tell him about it? >> yeah. >> this is an ongoing investigation, and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night, today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before, at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> reporter: be confrontational, because the clock is ticking. >> and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us you're responsible for killing your wife. >> no, no. i'm not, no. i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel i would get a divorce. i would not kill my wife over something that small. you know what? right now i guess i don't give a -- what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex, but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure, in some regards. >> reporter: why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100% certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlith a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? one piece of the puzzle, falls into place. boy, that was a huge development in that case. >> it was. >> reporter: and then, another round of heartbreak for lisa's family. this has gotta be more than your brain can absorb. >> definitely. if you have moderate to severe rheumatoid arthritis like me and you're talking to your rheumatologist about a biologic... this is humira. this is humira helping to relieve my pain and protect my joints from further damage. this is humira giving me new perspective. doctors have been prescribing humira for ten years. humira works for many adults. it targets and helps to block a specific source of inflammation that contributes to ra symptoms. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers including lymphoma have happened, as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment get tested for tb. tell your doctor if you've been to areas where certain fungal infections are common, and if you've had tb hepatitis b, are prone to infections, or have flu-like symptoms or sores. don't start humira if you have an infection. talk to your doctor and visit humira.com this is humira at work ♪ ♪ [ male announcer ] cats will do anything for the irresistible taste of temptations treats. what are you doing? oh, here check this out. ♪ ♪ [ meows ] temptations. cats can't resist. in a world full of dictates and conventions, could there be another way? ♪ ♪ la vie est belle la vie est belle, the eau de parfum, lancôme. receive a free gift. only at macy's your fragrance destination. >> reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> reporter: crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode and tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon, and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa and had just moved out. we showed lucas this photograph taken of seth at his home. if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes, it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> i told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa, but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. not too long into this sunday morning search, over here by this big old tree, what do you hear? >> i hear, "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20 yards from the back door of the trailer. boy, that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives -- was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's work friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here, someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: it sounds like they were making out rather than having sex. >> yeah, yes. that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby, and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect, and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know. did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. so you only had one suspect at this point. >> yeah, one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. your fellow officers are there as they would be, you know, they-- you know, want to show respect. >> right. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained, still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. i said, "is this a personal visit or professional --" >> reporter: is this condolences or somethin' else, huh? >> yeah, and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders, he arrested his friend seth techel. a fellow deputy put the cuffs on him. they were lisa's cuffs, the ones she'd used as a reserve deputy. so this has gotta be just more than your brain can absorb. >> definitely, yeah. >> reporter: little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sheriff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife. seth techel goes on trial. but before it even starts, the prosecution suffers a major blow. >> bad for us. good for them. it's great for them. >> reporter: and then -- a clue you haven't heard about could change everything. >> i believe it to be the most compelling piece of evidence in the whole case. toenail fungus? don't hide it... tackle it with new fda-approved jublia! jublia is a prescription medicine proven to treat toenail fungus. use jublia as instructed by your doctor. once applied jublia gets to the site of infection by going under, around and through the nail. most common side effects include ingrown toenail, application-site redness itching, swelling, burning or stinging, blisters, and pain. tackle it! ask your doctor now if new jublia is right for you. here at quicken loans, we like to go the extra mile for our clients. with the wassman family, it was 2,500 extra miles. we're the wassman family from skagway, alaska... livin' so far out i was runnin' into dead ends... happened to come across quicken loans online... walked over to the computer... i was able to see all the paperwork... while i was on the phone i was able to go through the checklist. they were quick and efficient. quicken loans is definitely engineered to amaze. they were just really there for us. at perdue, we pride ourselves on the freshness of our chicken. well, not that kind of fresh. but i can guarantee the freshness of our chicken because we go beyond what the usda requires... with extra inspections in american family owned farms, refrigerated trucks that deliver daily and everywhere in between. that's what it takes to bring your family a fresh tasting chicken. perdue. we believe in a better chicken. is there an elk in your bed? with sleep number now there's an adjustment for that. you can only find sleep number at a sleep number store. right now save 50% on the ultimate limited edition bed. know better sleep with sleep number. >> reporter: for lisa techel's family, it had been a heartbreaking, relentless week. thursday didn't promise to be any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now, he'd return to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pallbearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me? i was so proud. >> i should've been able to be there and -- and watch her become a mom. she was just a joy. >> reporter: mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. the coroner would think it was heart. >> yes. >> reporter: what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown -- from the state's attorney general's office -- worried that a jury might think the deranged, deceased, neighbor did it. their plan had been to call tate as a witness. >> on the theory that the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> reporter: february 2013, can you see yourself going into the courthouse? >> yeah, i remember. >> reporter: what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in- laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike, and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first degree murder and nonconsensual termination of a pregnancy. what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> reporter: how were you gonna mess with him? >> fill five gallon buckets full of dog manure and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law -- and the state agent who interviewed him -- the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dashcam video it became evidence for the prosecution. >> we feed the squirrels, birds and deer. >> we were hopeful that the jury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man. certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland -- the other woman -- to show up and tell her story. did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december, 2011, which was two months after seth got married. >> it became more sexual, asking me to send pictures. or, i don't know just showing off my body i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common and that he had tried working things out with lisa and things weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th when he learned that you were communicating with brandon, he said what? >> just give me two more weeks. >> did you ask him what he meant just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element -- sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him. >> no. >> never had your clothes off. >> no. >> and you kissed a few times. >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel. >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter- and-jelly sandwich, in a baggie, left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. in the jury room, deliberations -- and drama. >> he started pounding on the door saying that he wanted out of there. >> and we were in tears. all vegetarians, foodies and gastronauts kindly avert your eyes. you can't get juiciness like this from soy or quinoa. this is not greek yogurt. nor will that ever be kale! in its lifetime it won't be de-constructed or in-fused. and while it is massive... its ego is not. and therefore needs no introduction. ba da ba ba ba [ narrator ] mama sherman and the legion of super fans. wow! [ narrator ] on a mission to get richard to his campbell's chunky soup. it's new chunky beer-n-cheese with beef and bacon soup. i love it. and mama loves you. ♪ ♪ [coughing] dave, i'm sorry to interrupt... i gotta take a sick day tomorrow. dads don't take sick days, dads take nyquil. the nighttime, sniffling sneezing, coughing aching, fever, best sleep with a cold medicine. it was hard enough finding the right girl... ...but the perfect ring? there's no pressure there. finding the ring is the first step. that's why i partnered with the diamond experts at zales... ...to create... the vera wang love collection. it's got to be special. modern interpretations of... ...timeless designs... bring out the beauty in every bride. it's got to say yes. the vera wang love collection... exclusively at zales the diamond store. we come by almost every day to deliver your mail so if you have any packages you want to return you should just give them to us i mean, we're going to be there anyway why don't you just leave it for us to pick up? or you could always get in your car and take it back yourself yeah, us picking it up is probably your easiest option it's kind of a no brainer ok, well, good talk some cool things to pass onto your kids: your super heroes. your fashion sense. your love of reading. your uncanny ability to find parking spots. your fear of people who are different? not so much, the more you know. >> reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. they stay out and they stay out and they stay out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there. and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and three full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is granted. >> reporter: the judge declared a mistrial because of a hung jury. hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to retry the case. the vote had been ten to two for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven months later october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells, the daily treks to court, lives disrupted. the new courtroom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. >> reporter: other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," versus seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his, his own smiling face saying, "miss you bella." >> mm-hmm. >> is that a term of endearment that he called you, his bella. >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck. i love you" at 10:51 p.m. on may 24 of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her. i felt like she destroyed my sister's marriage and her life. >> reporter: todd, rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth but i think she's kinda been a victim as well. >> he's manic, he's up all the time. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> we're not going to reach a verdict. what's next? >> reporter todd, it's happening again. >> yep. and i'm thinking, "this is two months wortha trials and we're right back to the beginning." >> reporter: but the judge wasn't ready to give up. he told the jurors to keep trying. emotions in the open courtroom were raw, especially on the caldwell side. the jury couldn't help but hear it. >> presley and i were crying. we weren't crying uncontrollably or anything. but you could hear us sniffling a little. >> reporter: as the jury filed out, defense attorney steve gardner rose, to scold the spectators. stop the over-the-top outbursts, he said, or he'd demand a mistrial in fairness to his client. >> i do not desire this jury to be influenced by the public. >> reporter: now, it was the prosecutors turn to seethe. >> the defense is making this speech about the caldwell family trying to somehow influence the jury, which we thought was ludicrous, i squeezed andy's arm, and i said "i'll take this." >> to stand up here and suggest that anyone in the courtroom is trying or attempting to intentionally influence the jury is absolute nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here. >> reporter: for more than a minute, glaring, burning a hole in seth's back. if looks could kill. >> there's just kind of an urge to move forward. >> reporter: to jump the rail? >> yeah. god, please don't make me do that. just let me stand. >> reporter: what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was -- i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. >> a mistrial is declared. >> reporter: unbelievable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction, this time nine to three -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like -- he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings by a brand new defense team. >> i heard it about a week before the trial and it -- just like somebody hit me in the stomach. the defense comes out swinging, >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint, confession. [goat screams] ♪ elevator music ♪ [goat screams] ♪ elevator music ♪ [donkey braying] ♪ upbeat music ♪ bring in your verizon or at&t bill, turn in your old phone and we'll cut your rate plan in half. visit us online or visit a sprint store today man (sternly): where do you think you're going? mr. mucus: to work, with you. it's taco tuesday. man: you're not coming. i took mucinex to help get rid of my mucusy congestion. i'm go od all day. [announcer:] mucinex keeps working. not 4, not 6 but 12 hours. let's end this thank you, cable for the slower internet upload speeds. for making me wait longer to share my photo albums. thank you cable, because if we never had you... ...we wouldn't know the incredible difference verizon fios makes. in customer satisfaction studies, fios is rated #1 in internet speed and reliability - 8 years running. plus, fios has the fastest wi-fi available from any provider. for a limited time, get a fios triple play online at an amazing $79.99 a month guaranteed for two years. plus, a $400 bonus with a two-year agreement hurry, deal ends february 21st. call the verizon center for customers with disabilities at 800.974.6006 tty/v >> reporter: two families. two trials. and so far, no winners. but trial number three promised to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint -- confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? no, we forgot, or we didn't do it. >> reporter: whoops. >> whoops. >> reporter: the new defense team had a new story to tell -- it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the boogeyman of the first two trials -- brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> the caldwells and techels had been put through the wringer for more than two years, their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person." >> reporter: did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing with you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july 2014, for the third time, the state of iowa versus seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, "forever." >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well, we talked. i told her i wasn't happy, she got mad then sad, then i slept on the couch, so hello, mrs. resuscitator." >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mr. resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had and that included explosive new evidence. this time, it was about lisa. you've had this story. there was this guy, a co-worker. >> was there another man in lisa's life? when used at the first sign. without it the virus spreads from cell to cell. only abreva penetrates deep and starts to work immediately to block the virus and protect healthy cells. you could heal your cold sore, fast, as fast as two and a half days when used at the first sign. learn how abreva starts to work immediately at abreva.com don't tough it out knock it out, fast. with abreva. hey nice game today. thanks. juicy fruit? sure i'll try a piec.... juicy fruit. so sweet you can't help but chew. [announcer:] what if one stalk of broccoli could protect you from cancer? what if one push up could prevent heart disease? [man grunts] one wishful thinking, right? but there is one step you can take to help prevent another serious disease- pneumococcal pneumonia. one dose of the prevnar 13® vaccine can help protect you ... from pneumococcal pneumonia, an illness that can cause coughing, chest pain difficulty breathing and may even put you in the hospital. prevnar 13 ® is used in adults 50 and older to help prevent infections from 13 strains of the bacteria that cause pneumococcal pneumonia. you should not receive prevnar 13 ® if you've had a severe allergic reaction to the vaccine or its ingredients if you have a weakened immune system, you may have a lower response to the vaccine. common side effects were pain, redness, or swelling at the injection site. limited arm movement, fatigue, head ache muscle or joint pain less appetite, chills, or rash. even if you've already been vaccinated with another pneumonia vaccine, prevnar 13® may help provide additional protection. get this one done. ask your healthcare professional about prevnar 13® today. look what i got with walmart's low prices. these are for the parent teacher conference. nice these are for when the kids do something good, i get that. and these are for when i want to come off totally laid-back. totally. with frames starting at $38, you don't have to choose just one. walmart. the bed reacts to your body. it hugs you. i don't have to think about how to get comfortable anymore. this zips off so i can wash it-yes, please. dude, tempur-pedic is killing it. no more tossin' and turnin', trying to find a comfortable spot in bed. it's really cool to the touch. my tempur-pedic... cuddles better than my husband does. but that's just between you and me. (vo) visit your local retailer and feel the tempur-pedic difference for yourself. >> reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. get him. now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel, offered as seth's motive for murder in earlier trials, was also minimized this time. >> good afternoon, miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man right? >> correct. >> and the only time you'd actually seen him in person, in your whole entire life, outside of work, was four or five times. >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the ayes have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it. >> yeah exactly, we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel. >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we -- we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. >> lisa's lover was a married man, a father of four. >> reporter: and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter had a lover was the cruelest blow yet. >> the first emotion i had is, "why? why, lisa?" you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> reporter: does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all. >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. 'cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kinda think, "okay. if i was on this side, that's kinda how i woulda handled it." "they're doin' a pretty good job." and i'm convinced it's gonna be another hung jury. why wouldn't it be? todd, and just about everyone else, are in for a surprise. >> has this jury reached a verdict? i don't know what it is... the food, stress or running around but sometimes i feel bloated or gassy, with rumbling, uncomfortable. i feel sluggish and cranky. grrrr! (dog wimpers) you're right, bailey! i need a change! i'm taking the activia challenge! enjoying activia twice a day for four weeks may help reduce the frequency of minor digestive issues like bloating, gas discomfort and rumbling. and if your tummy smiles you can feel like you. try the activia challenge! it works or it's free! ♪ dannon ♪ start the interview with a firm handshake. firm, but not too firm. make eye contact...smile. ay,no! don't do that! try new head & shoulders instant relief. it has tea tree and peppermint that cools on contact. and also keeps you 100% flake free. i use it for cooling scalp relief in a snap. mi bebé ha crecido tanto. try new head & shoulders instant relief. for cooling relief in a snap. [ julie ] the wrinkle cream graveyard. if it doesn't work fast... you're on to the next thing. neutrogena® rapid wrinkle repair has the fastest retinol formula to visibly reduce fine lines and wrinkles in just one week. neutrogena®. kmart has great deals so you can get more this valentine's day. like this 1/5ct diamond heart pendant with free chocolate truffles for $99.99 and 25% off plush toys. kmart. where members always get more. ♪ miranda: ♪ i got red dirt stains on my boots and jeans. ♪ ♪ calloused fingers from my guitar strings. ♪ ♪ wild like the wind in the tall pine trees. ♪ ♪ i got roots and i got wings. ♪ ♪ with rollover data, the data you don't use this month rolls over to the next month. and i don't have to do anything? not a thing, mobile share value customers get it automatically. it's how we show appreciation. you know i really appreciate that you appreciate me as a customer. and we appreciate how much you appreciate us appreciating our customers. and i appreciate that you appreciate that. and i appreciate you appreciating that. i appreciate that. aaaahhhh. introducing at&t rollover data. the data you don't use rolls over to the next month. all on the network with the nation's strongest lte signal. >> reporter: july 24, 2014. after two agonizing stalemates, this time things were different. as seth techel walked into the courtroom and sat down his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family, and certainly not at todd, his former father- in-law. this is the young guy you used to clap on the back and say, "i love you." >> yep. "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now, the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one -- we the jury find the defendant seth andrew techel guilty of murder in the first degree. signed by the head juror. count two -- non-consenual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. and then you hear the words? what do you see? >> i hear the words guilty. and i see nothin', not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26, and then, there's seth from may 26 on, and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent-up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. we know this family. i know it's not doug and lorraine's fault. it's not their family's fault that any of this happened. todd searched out doug. only three years before, they were all celebrating their kids' wedding together. doug and lorraine still support their son and say he didn't do what he's now convicted of doing. do you have a whisper of doubt, either of you? >> no, sir. >> none whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment, too. >> i started cryin'. it wasn't tears of sorrow, it was tears of joy. they had finally gotten this s.o.b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're gonna have last word on brian tate. this is an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held in september 2014. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley, lisa's sister, walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and, for the first time, seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister, and i no longer love you. >> reporter: and then the judge handed down the sentence. life in prison, with no possibility of parole. when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. what are the figures in it, todd? >> the first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holdin' a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook," movie and it's -- we've always said, "if you're a bird, i'm a bird." you know, i mean, whatev -- whew. "whatever you are, i am." so in the hair of this, i made two birds in there, by the time i got it done with, you know, we all loved it. and it's kind of just, kinda bonded like, you know, "hey, this is part olisa now." >> 10 seconds! [ laughter ] >> ♪ now promenade your sweet, little maid ♪ ♪ take that girl and give 'er a whirl ♪ all right! give yourselves a big hand now! [ cheers and applause ] [ dramatic music plays ] >> johnny! >> johnny, i thought they fired you. >> well, they did, pete. but i gotta ask one last favor. can you call this?
grief. it was a tragedy, but for lisa's dad, he was sure he knew who the killer was. a neighbor with a gun and a grudge. >> i thought they better get to him before i do. some said this couple was having trouble, and that seth had a secret others said that the real murder was someone else right under cop's noses. a case unfolding on camera that would test three families and take one final twist. >> that the biggest's. >> the cornfields from iowa are far from nashville, but a little girl was named lis ama ama mar. >> she lived up to her big name. >> she was the life of the party. >> they're divorced now, but tracey and todd caldwell watched their girl grow up unstoppable. >> we're not just talking about recreational saturday night. >> anything she did, she had to be the best at. lisa was a teenager when her parents divorced. todd remained an active fwauath. he was working as a depty in the wapello sheriff's department. one was his occasional hobby. he'd take out his sketch pad from time to time. and then he met and fell hard for a nurse named amy. before long, he was starting fatherhood all over again. with twin daughters this time, he was getting lots of help from lisa. she was the twins' default babysitter. she was more like a second mom to the twins than a big sister. >> she was just a caregiver to anybody. >> reporter: you had a very close relationship? >> uh-huh, very. i would get into bed with her. we'd watch old episodes of the golden girls. [ laughter ] >> reporter: that's a sweet relationship. >> yeah, and she always says that i was dorothy because i'm such a grouch all the time. [ laughter ] but yeah, that was my favorite time with lisa. i'm so lucky. >> reporter: but step-mom amy put on her enforcer hat when it came to lisa's teenage romantic life. >> i wanted to know who the boyfriends were. i wanted to know who their parents were. [ laughter ] i was the one that they had to pass the test with. >> the boyfriend who passed with flying colors was seth. he came from a long time local family. his grandfather was the mayor. mom was a social worker, the dad owned a local bowling alley. the bowling alley was where seth as a young teen began noticing lisa. his dad was her high school coach and seth bowled almost but not quite as well as lisa. the two worked part-time together at the lanes. they were becoming boyfriend/girlfriend and that was fine with both families. >> you liked this young girl? >> a lot. >> she was a part of our family. >> they were a church going family and seth's mom remembers how the compassion shown on a relief mission to mississippi after hurricane katrina. >> he just would talk to the folks for hours and hours. they became very good friends. i have a lot of memories like that of seth. >> helping people. >> yeah. and lisa wanted to help people, too. she followed her father into law enforcement and then as a jailer in a neighboring county. >> i told her that she would have my blessings if she wasn't just an average cop. i wanted her to be a really great cop because i didn't want to have to worry about her inefficiencies maybe endangering her life. >> after years of hearing patrons at the bowling alley joke about when they would get married, they made the inevitable official. >> how did you find out they were getting hitched? >> seth came to our house and met with us and asked us our permission to marry lisa. old school. >> old school. >> after dating for seven years, seth and lisa got married in october 2011. she was 22, he was 21. >> i just told him that, no matter what he did, to take care of her and protect her. >> and he said? >> he said he would. >> lisa's sister, another namesake, got much more than a brother-in-law with seth. >> he was my best friend and he was that other person that i could always go to. >> he called me dad. we told each other we loved each other. we hugged every time we left each other. i felt as close to him as i did my son. >> for lisa, it wasn't just gaining a husband, it was having all his buddies come along, too. a package deal. >> how did she put up with you guys? >> she was interested in the same things that all of us were. she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> sounds like you would have been happy if she were your girlfriend? >> seth was lucky. >> lucky for sure. but seth knew it was time to settle down and get a real job. like lisa, he was drawn to service. he signed on as a firefighter. he drew a paycheck as a security guard. his father-in-law todd was helping him get a higher rung in the ladder. the soon to start job as a jailer for the sheriffs. >> they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> now more changes for seth. he was going to be a father. they picked a name for the unborn girl, zoe maria. in may 2012, they were halfway through the pregnancy. >> seth and lisa, a baby on the way were starting out their married life in this humble little trailer. it was a gift from his dad purchased on a beautiful piece of property. a starter home to save money for the future. the only apparent cloud in the picture was an escalating feud with an across the fence neighbor. there was bad blood. it happened at 5:00 in the morning. a sudden horrifying sound that shattered two young lives. >> 911. >> saturday, may 26, 2012, memorial day weekend. >> not breathing. >> does she have any medical problems? >> she's been shot. >> a shotgun blast that ended all the plans of mr. and mrs. seth techel. deputies race to the scene where the shooter could be lurking anywhere. >> someone could have shot you. that was possible the whole time. turns out it's mostly water. so, we switched back to tide. one wash, stains are gone. daughter: slurping don't pay for water. pay for clean. it's got to be tide. special guest flo challenges the hand models to show off the ease of comparing rates with progressive's home quote explorer. international hand model jon-jon gets personal. your wayward pinky is grotesque. then a high stakes patty-cake battle royale ends in triumph. you have the upper hands! it's a race to the lowest rate, and so much more. only on "the upper hands." shh! i took mucinex dm for mye, phlegmy cough.h more. what about rob's dry cough? works on that too, and lasts 12 hours. 12 hours?! who studies that long? mucinex dm relieves wet and dry coughs. your happy place. find your breaking point. then break it. every emergen-c gives you a potent blend of nutrients so you can emerge your best with emergen-c. (har(betsy) twelquarter mile of tinsel. lights. (harold) and real snow all the way from switzerland. (betsy) hmmhm... gonna be tough to top. ♪ (betsy) well played. (vo) add some thrill to your wish list. at the season of audi sales event. get exceptional offers now. a livcustomizeper iquickbooks for me. okay, you're all set up. thanks! that was my business gi, this one's casual. get set up right with a live bookkeeper with intuit quickbooks. >> reporter: it was the end of a long overnight shift for sheriff's deputy marty wonderlin, the only deputy on duty in wapello county, iowa. all was quiet and with the first hint of daybreak that saturday morning, marty relaxed and turned up the music in his cruiser. >> reporter: it's the ragged end of the shift for you, huh? >> yeah, i'm taking my last little loop around the county and going to watch the sun come up and go home and go to bed. >> reporter: that plan came to an abrupt end around 5:30 a.m., when seth techel made a desperate 911 call from his house. >> she's been shot. i'm going to [ bleep ] kill who -- i was getting ready for work and i heard a gunshot and i came running out and she was shot in the side. >> reporter: dispatch relayed the message to marty wonderlin. the young deputy had never gotten a call like this. >> i have a report of a lady not breathing. i have now been advised this lady's just been shot. >> reporter: is your heart pounding a little? >> oh, yeah. that's an understatement. >> reporter: with his car and his mind both doing 90, marty raced to the house in under ten minutes. he slowed along the rise of the gravel country road and stopped at the end of the driveway. he had no idea what he'd be facing. his dashboard camera captured the scene as he approached the house. >> reporter: here's how you get in the trailer. what do you see, right about here? >> you could see seth techel up on the porch. he was wearing cargo shorts and a belt, and he just bent over, you know? >> reporter: what's he doing? >> sounds like he's crying, just sobbing. >> reporter: the toughest call of marty's career was suddenly so much more complicated. he knew the grieving husband on the porch, considered him a friend, knew his wife lisa too. and her father, todd, was a respected, fellow deputy. the unfolding tragedy had just become very personal. >> reporter: deputy, how do you set your brain in compartments, where you got to be very professional? this is the first time you've had a major crime, and yet it's also people you know? >> it's tough. >> reporter: were you scared? it's okay if you were. >> yeah, definitely was scared. you know, concerned about a lot of different things. >> reporter: you didn't know if somebody could have winged a shot at you? >> yeah, i mean, that was possible the whole time. >> reporter: as the only cop at a dangerous, chaotic scene, the possibility of a live shooter still on the grounds, marty's adrenaline was pumping. when he entered the trailer, a paramedic was attending to lisa. she was lying in her bed. it didn't look good. marty's only thought was to help her, but he had to secure his rifle, so he ran back to his cruiser to lock it up. >> i got on my radio and i think i told dispatch, "get 58 out here." >> call 58 and have him get out here. >> reporter: badge 58 meant deputy todd caldwell, lisa's father. >> in hindsight, i wish i wouldn't have done that. i wish i would -- >> reporter: why do you say that? >> well, because i saw a lot of things that morning and now because of me, because of asking him to, you know, come out there, he's going to have to live with some of those same images that i do now. >> reporter: todd caldwell was asleep, but his cell phone was plugged in next to the bed, always ready for a middle-of-the-night emergency call. >> we get a call from, you know, a dispatcher i've known for 20 years and i can tell that his voice is different. and from what i remember, he just said, you know, "you need to get out to lisa's house. she's been shot and isn't breathing." >> reporter: todd's wife amy bolted out of bed. her step-daughter, her best friend, needed her. >> i kinda left him behind. i didn't put shoes on, didn't have socks on. i went in my pajamas and drove 90 miles per hour, you know? i'm an e.r. nurse. i'm thinking -- >> reporter: you're sort of in nurse mode there too? >> yeah, i'm thinking, "well, you know, maybe if i get there fast enough -- >> minutes matter. >> there will be something i could do. todd raced behind in a separate vehicle. >> i just repeated over and over, you know, "oh my god. oh my god, oh, my god." i just remember that's all i could think and say is, "oh, my god. oh, my god, oh, my god." >> reporter: at the scene, deputy wonderlin ran back to the house and did what he could to help the emt. >> started giving lisa cpr, so the paramedic could -- i think he was getting, like, a defibrillator ready. it felt like forever. you know, and i'm asking him, you know, "you want me to do cpr still?" he told me not to. >> reporter: there was nothing more to do. she was gone. along with her unborn daughter. lisa marie techel was just 23 years old. >> i ran in there and you could tell that she was gone. >> reporter: so you went into the bedroom? you saw her? did you tend to her? >> yeah, i held her hand and i rubbed her belly and i just said, "my -- my lisa, my lisa." >> reporter: todd, did you go into the house? i hope not. >> yeah, i did. i went in there and i seen her laying there and i seen the amount of blood that was on the bed and i knew, from my experience, that that was too much blood to sustain life. when i listen to like the tape recording of it, i hear myself bellowing. i don't know how to describe, but i don't even remember doing that. >> what happened? >> reporter: it was a heartbreaking scene, but deputy marty wonderlin had a job to do. end of your shift, your first homicide. so you're in the barrel here. >> got to start working it. >> reporter: there was an immediate lead from, of all people, todd caldwell. the veteran cop, who had just seen his precious daughter lying dead in a pool of blood, said he knew who the shooter was. and in a voice filled with rage, he told his fellow deputies to take the suspect down. >> that [ bleep ]. go get him. go get him, now. >> who was todd caldwell talking about? turned out there was someone in seth and lisa's life that had everyone worried. >> things were escalating. they were fearful, i was fearful. >> did you think he was a risk? >> i did. i did. >> when "dateline" continues. >> when "dateline" continues another bundle in the books. got to hand it to you, jamie. your knowledge of victorian architecture really paid off this time. nah, just got lucky. so did the thompsons. that faulty wiring could've cost them a lot more than the mudroom. thankfully they bundled their motorcycle with their home and auto. they're protected 24/7. mm. what do you say? one more game of backgammon? [ chuckles ] not on your life. [ laughs ] ♪ when the lights go down ♪ i got it all from you ♪ i'm always pushing through ♪ i know we'll make it to the finish line ♪ ♪ i know you're waiting on the other side ♪ ♪ i'm like you on-demand glucose monitoring. because they're always on. another life-changing technology from abbott. so you don't wait for life. you live it. >> reporter: lisa techel was dead, murdered in her own bed. her distraught husband seth was outside, shirtless and barefoot. when lisa's little sister presley arrived, all she could do was try to comfort him. >> by the time i got there, they had stuff taped off. and i went up and i just gave seth, like, the longest -- it seemed like the longest hug ever. >> your best friend. >> yup. >> reporter: seth was inconsolable, and acting out. >> i went over to him when i first got there and i tried hugging him. he pushed me away. he punched his truck, and i said, "don't do that, seth, you know, let me see your hand." >> reporter: todd offered to take seth back to his house, but doug techel knew this was a moment his son should be with him. >> it was just bad. i mean, it -- he was sobbing. and we just hugged and cried. >> reporter: marty wonderlin, working his first homicide, was the first deputy to speak to seth. how'd that go? >> you know, i ask him what happened. >> i came running out. and i looked in the bedroom and she's laying there. >> reporter: through the overwrought husband's sobbing, a story started to emerge. >> he basically tells me that he was in the shower gettin' ready to go to work, and he hears a gun go off. >> i ripped open the -- shower curtain and i grabbed my towel and i came out. i didn't see anybody down the hallway. i'm gonna kill whoever the -- did this. >> reporter: there's been some sort of an intruder. >> yeah, that's what he's tellin' me, that someone came in while he was in the shower, shot lisa and ran away before he could catch him. we'll figure it out, brother. >> i can't -- tell todd. >> we'll figure it out. >> reporter: lisa's father todd thought he'd figured it out and already had a suspect. >> that -- go get him. go get him. now. >> reporter: todd's rage was directed at the neighbor on the other side of the fence topped with barbed wire, a 56-year-old disabled army veteran named brian tate. >> i just remember saying, "go get him. go get him now," and i thought, "they better get to him before i do." >> reporter: brian tate had been embroiled in an escalating feud with his neighbors lisa and seth. todd knew all about it, and was certain his daughter was now dead because of it. this is this culmination of bad blood's been goin' on for a month's time or more now? >> right. uh-huh. >> reporter: it started about two months before the murder. seth pulled a dead deer off the road along the property line. brian tate later tossed the hide onto seth's property. seth tossed it back, and the battle was on. tate made several calls to the county, complaining about nasty acts of vandalism. todd caldwell responded to one in april. and tate pointed the finger at his young neighbor. >> i can't remember names. >> seth, seth techel. >> seth techel? >> yup. >> torkel? >> techel. >> techel. >> yeah, his dad owns champion bowl. okay. >> and i'll tell -- i just -- they're good people. they really are. >> reporter: now this guy, brian tate, does he know that you're the father-in- law of the neighbor? >> no, and i don't wanna tell him that because i don't want that to affect maybe what he does or doesn't do. >> reporter: and he thinks that's the source of his trouble? >> right. >> reporter: those people over in the trailer property across the way? >> yeah. >> well, if you can, let us deal with it. >> what if -- what if -- what if i'm the one who's gotta catch him? >> reporter: brian tate told todd that dog feces and rocks had been hurled at his home. he then showed todd the evidence. he described the vandalism of his home in stark terms. >> he says that he thinks these are acts of terrorism and, you know, kind of - - a bell goes off like, "terrorism's kind of a weird word to use." and the whole time -- half the time, i guess, he's sitting there. he's -- i notice a shotgun layin' on the ground, you know? and i'm like goin' "that makes me feel a little --" >> reporter: does that make you a little twitchy? >> yeah, yeah. exactly. >> reporter: so twitchy that todd sent a heads-up email warning fellow deputies about tate, that he might be dangerous. >> i'm thinkin', "i don't wanna be the reason a deputy goes out there and gets hurt." okay, if you go out there, be careful. tate might be 1096, which means mentally, you know, challenged. >> reporter: in fact, tate did have a history of mental illness. he'd been diagnosed as a paranoid schizophrenic. seth's mother lorraine, a social worker used to dealing with mental patients, was worried and talked to both seth and lisa about their neighbor. >> she was terrified. this was when things were escalating. they thought that they could, you know, handle whatever. and um -- but they-- they were fearful. i was fearful. >> reporter: on may 15th, just 11 days before lisa was killed, an agitated tate made another call, complaining that the vandalism -- the terrorism -- was getting worse. todd responded again, this time accompanied by fellow deputy don phillips. >> i'm trying to have a conversation with you. you know it? >> i don't wanna be yelled at either. >> well, i'm trying to have a conversation with you and i don't understand why you're walking. >> you're raising your voice at me. >> i, you're right. i am. >> what i'm wondering -- >> because you're not listening. >> reporter: did you think he was a risk, that this was -- >> yeah. yeah. >> reporter: a guy who was capable of flipping out? >> i -- i did. i did. >> reporter: and now, lisa was dead, and the trailer was a crime scene. marty wonderlin, the first deputy at the scene, already knew all about brian tate and had zeroed in on him as his candidate for prime suspect. all the direction is heading across the fence to this guy whose name is brian tate. >> it is. >> reporter: and police decided it was time to pay a visit to tate. they armored up and got out their long guns, not knowing what their suspect might do. >> if you're ballsy enough to break into a house, shoot lisa and make it back out, you're ballsy enough to do just about anything. >> cops confront their man. >> i had my rifle locked and loaded. if things popped off we were ready. ngs popped off we were ready. you know if your plan is still the right fit? having the wrong plan may cost you thousands of dollars out of pocket. and that's why i love healthmarkets, your insurance marketplace. with healthmarkets' fitscore, they compare thousands of plans from national insurance companies to find the right medicare plan that fits you. call or visit healthmarkets to find your fitscore today. in minutes, you can find out if your current plan is the right fit, and once you've let the fitscore do the work, sit back and enjoy not having to shop for insurance again. healthmarkets' fitscore forever technology will continuously scan the market for the best coverage at the best price. so you can shop once and save again and again and again. rest easy, knowing you'll have the right plan, at the right price, and the right fit for you. best of all, their services are completely free. does your plan have $0 copays, $0 deductibles, and $0 premium? if not, maybe it's not the right fit. does it include dental and vision coverage? well, if not, maybe it's not the right fit. how about hearing aid, glasses, and even telemedicine, at no additional cost? maybe there's a better fit for you. call healthmarkets now, or visit healthmarkets.com for your free fitscore. they can instantly compare thousands of medicare plans with all these benefits and more, including plans that may let you keep your doctor and save money. healthmarkets doesn't just work for one insurance company. they work to help you, and they do it all for free. having helped enroll americans in millions of policies, while earning an a-plus customer satisfaction rating from the better business bureau, you can trust healthmarkets. with the annual medicare enrollment deadline coming, go to healthmarkets.com, or call right now. your insurance marketplace. healthmarkets. find your fitscore and get your answers today to get the most out of medicare. call now. itthe north pole has to and be feeling the heat. up, it's okay santa... let's workflow it. workflow it...? with the now platform, we can catch problems, before customers even know they're problems. wait... a hose? what kid wants a hose?! fireman? says "hose". -it says "horse"! not a hose! cedric! get over here! now our people can collaborate across silos, from across the globe. so how's the new place? it's a 4 bed, 2.5 bath igloo... it's great! yeah, but you have to live in the south pole. sir... -wait, are you sure? yes, we're that productive now. you hear that?! the kids get twice the presents! about time 2020 gave us some good news. whatever your business is facing... let's workflow it. servicenow. on the main street of a little town in iowa, a woman was dead an a killer on the loose. >> the 23-year-old reserve sheriff's deputy was killed and she was pregnant. deputy john phillips had a personal stake in cracking the case. lisa's dad, i just reassured him that we will figure this out. >> whatever happened here is really within your family? the law enforcement family of the county? >> yeah, we know everybody. we know everyone's extended family and kids. >> and they also know something about the guy next door. they had been bapeeking across e bashed wire. at 1:00 that afternoon. deputy phillips and a team of investigators were ready to confront the neighbor. ever since the first deputies arrived at sunrise, they'd been peeking across the barbed wire. just how dangerous was this fussing neighbor? >> we got strapped up. we're all ready. ready for business. >> reporter: marty was in the backup car, while deputy phillips and a partner drew line-of-fire detail -- approaching brian tate for an interview. >> he's our prime suspect. it's very possible in all of our minds that he just shot and killed lisa. >> reporter: as the phillips team walked slowly up to the tate house, marty and the chief deputy provided cover in the driveway. >> i had my, my rifle out, locked and loaded. had the red dot turned on. if things popped off, we were ready. >> reporter: nerves screaming, everyone was poised for battle, everyone but, it turned out, brian tate. he wasn't armed, or belligerent. they could all exhale. >> as we walked up there, he was accommodating, got some chairs out for us. >> reporter: this is brian tate, huh? >> brian -- brian did. and we sat down in his front yard. >> reporter: in the front yard in lawn chairs, his mother and brother by his side. no shotgun in sight. so the cops turned on a recorder and started asking questions. you asked him, "5:00 a.m., where were you, huh?" >> yes. >> reporter: he said he was in bed in his basement bedroom, sleeping off a higher dose of medication for his schizophrenia. >> i went to bed about 8:30. >> right after i did. >> yeah, after mom did. fell right asleep. didn't hear nothing. didn't get up till 11:00. >> reporter: he said he was still asleep when the shooting must've happened before dawn. tate's mother corroborated his 15-hour sleep alibi, though the cops knew full well that mothers can often be biased witnesses. >> did you hear anything in the middle of the night last night or see anything? >> i was in bed and normally i would've been up doing guard duty with all this that happened. but, i'm schizophrenic paranoid. >> reporter: guard duty. the ex-military man called himself a sergeant major and walked the picket on his property line, vigilant ever since his property had been littered with dog feces, his barn pelted with rocks. deputy don phillips knew all about the vandalism complaint tate had filed. he and todd caldwell were the deputies who'd responded to tate's house just 11-days earlier. they'd downplayed his complaints then and thought he was a crank off his meds. >> you said earlier, brian, that you, you'd sit outside here. >> at night? >> at night, yeah. when's the last time you did that? >> oh, it's been a good week or so. >> week or so? >> they don't want me to do guard duty anymore. they want me to get sleep, take more medications. >> you were such a calm quiet guy until this vandalism started, and then you're just like a different person. >> i was mr. nice guy for a long time. it done me no good. people took advantage of me, so i'm kinda taking a different approach to life right now. >> i mean when -- >> being more serious and more not such a nice guy. >> reporter: after venting about the vandalism, the 40-minute interview was over. but investigators weren't done. they'd be back to question tate again. so what'd you think you had when you got back in your vehicle? >> we still had a whodunit in our mind. >> reporter: but lisa's step-mom and sister had no doubts whatsoever. >> i thought it was brian tate. >> reporter: but investigators knew they still had to talk to the husband. when agents scheduled an official interview with seth for that same day, it didn't sit well with amy. >> is this how you -- how you always treat grieving husbands? and i started crying. i'm there thinking, "they're being so mean to him." >> we kinda got into an argument 'cause i'm like, "they have to do that." >> reporter: would-be cop seth techel agreed completely. he knew the spouse had to be ruled out. he said he was eager to get crossed off the suspect list as soon as possible. so he went downtown and instructed his parents no lawyers. >> i remember sayin', "do we need to go get a lawyer?" >> he was adamant. he said, "no." >> he said, "i didn't do anything." >> "i have nothing to hide." >> "i don't need a lawyer." >> reporter: was that a mistake? seth had told his story to one familiar face after another at the scene. but now, he'd be talking to an elite state interrogator, and the tone of the investigation was about to change. deputies learn that seth may be hiding something. >> told them that seth had a tracfone. >> a secret phone. >> yeah. pors for her, for you, for the whole family. trusted soothing vapors, from vicks your happy place. find your breaking point. then break it. every emergen-c gives you a potent blend of nutrients so you can emerge your best with emergen-c. we started by making the cloud easier to manage. but we didn't stop there. we made a cloud flexible enough to adapt to any size business. no matter what it does, or how it changes. and we kept going. so you only pay for what you use. because at dell technologies, we stop...at nothing. ♪ we're all finding ways to keep moving. but how do we make sure the direction we're headed is forward? at fidelity, you'll get the planning and advice to prepare you for the future, without sacrificing the things that are important to you today. we'll help you plan for healthcare costs, taxes and any other uncertainties along the way. because with fidelity, you can feel confident that the only direction you're moving is forward. ed to. >> my remaining kids, i knew they were going to be horrified. i don't even think about myself at that point. >> but today was thinking about the moi that he loved like his own boy. why show the county deputies called in state agents from the dci. iowa's division of criminal investigation. it became a shared investigation, the dci providing forensic resources and expertise, the deputies offering local knowledge and manpower. dci's tony birmingham was lead agent. he hand-picked fellow agent chris thomas to interview seth. >> there was no doubt in my mind that chris was the person that needed to do that interview. >> we only get one shot at it. and we have to be prepared that this could just be information collecting or we have to be prepared that this could be our suspect. >> reporter: so, only eight hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got under way. >> you can just call me chris, i guess. you're free to, uh, go out of here at anytime. >> reporter: in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him sat in. >> you have a job? >> reporter: it started routinely. >> currently, i work out at uh job corps as security, but actually next month i'm coming to work here in the jail. >> reporter: seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. his story begins somewhere around 5:00 a.m. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> reporter: he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound, coming from possibly the back deck. he said he grabbed his handgun from the nightstand by the bed. >> i run down the hallway and i will be honest, i had every intention of shooting whoever it was. i don't see anybody. i don't hear nothing. i run back inside. i run into the bedroom. and i said, "lisa, lisa, are you okay?" and she's not breathing. >> reporter: during the interview, seth sometimes seemed overcome by emotion. >> i couldn't do it, i couldn't protect her when i'm 10 feet away from her. why can't they still be alive? why? why? why couldn't i have done something to protect the woman that i loved? date? a crazy ass neighbor that thinks we're terrorists are. he suspected that date totate tt over the fence. >> i did the immature thing, i threw it back on his property. >> the dispute escalated for several weeks and intensified with the incident when dog feces and rocks were thrown on to his property. that brought todd kacaldwell. he filled him in later. his father-in-law also gave him a strong warning, if you're doing anything, knock it off, if your friends are, knock it off. don't mess with him, he is off his rocker. i said i'm not messing with him. >> the murder weapon had not been found, so the state agent asked him. >> are there any gun that's are missing? >> i have not looked. and we ask him to write down the guns in his house. and he asked him to write it all down. >> he turns to the sharp edged intrusive question that's all of those with a murdered wife have to answer. >> he knew very well what was coming. >> i know i'm probably number one right now. >> let's talk about people in your lives. was there any extramarital affai affairs? >> seth didn't hesitate. there was no other women. but out of the trailer quite unexpectedly someone was about to put the lie to that rosy marital picture. he told the deputies and agents there he was looking to pick up his puppy that seth had been boarding for him. they were peppering the young friend for info about seth and lisa. >> what was the story you told him. >> i told him that seth had a tracfone. >> a secret phone? >> yeah. he had been talking to a girl. >> reporter: the investigators had no idea where this would lead, but the unexpected revelation that there might be a girlfriend in the mix meant that they had to get on the horn with agent thomas downtown and pronto. seth was still in the interview chair, but he could walk at any moment. more about seth's secret phone. seems it wasn't just for talking. >> did he tell you she sent me some topless pictures? >> yeah. >> did you see them? >> yeah. tide pods with upgraded 4-in-1 technology unleash a foolproof clean in one step. aww, you did the laundry! it's got to be tide. ojust one jar of olay retinol24? hydrates better than the $100 retinol cream. for smooth, bright skin or your money back. olay. face anything. and try new retinol24 max. well, here's to first dates! you look amazing. and you look amazingly comfortable. when your v-neck looks more like a u-neck... that's when you know, it's half-washed. try downy fabric conditioner. unlike detergent alone, downy helps prevent stretching by conditioning and smoothing fibers, so clothes look newer, longer. downy and it's done. >> reporter: seth techel had gone downtown voluntarily, but now his interview had dragged on for a couple of hours. his father grew concerned, so he called in a lawyer, who said he would bring the questioning to a halt. >> and we had called the sheriff's office and said, "we have a lawyer waiting to go see seth." >> reporter: but inside the sheriff's interview room seth kept talking away. he was oblivious to the fact that the interrogator confronting him was getting real time bulletins from the crime scene. >> i got a text. >> reporter: the text was from a fellow agent at the scene who had spoken to seth's best friend, the guy with the puppy. >> reporter: and this person had told him a story about a girl named rachel. but agent thomas held his fire at this point, in part because his information was still limited. seth, however, likely could see the agent reading a text. the husband -- father-to-be, who had answered an emphatic "no" to the question about an affair, then made an admission, perhaps a preemptive strike. >> there was a female from work that i was texting. >> reporter: he said her name was rachel mcfarland, but seth immediately downplayed her importance. he said even lisa knew about her. >> but i wasn't seeing her, it wasn't anything. it was just, "hey, how was your day type of thing." >> would it be considered sexting? >> no, no. none of that. >> what are you wearing? >> no, there wasn't any of that. lisa found out. everything was kosher. i stopped talking, you know, we got over it. >> we have to be honest about her, okay? is there anything that you haven't told us yet? >> no, everything is going to add up the way i just told you. >> rachel's dna won't be maybe on your clothes or? >> i never had sexual -- sex with her. no, nothing oral, nothing like that. um, i gave her hugs, and i've kissed her. >> reporter: by now, seth's father and attorney had arrived and were trying desperately to end the interview. but it was after-hours, and the outside door was locked. >> bang, bang, bang on the door, doug. is that you? >> that's me. that's me. >> they wouldn't stop. >> they -- >> they didn't come out. >> didn't stop. >> reporter: they didn't have to. remember, seth was advised by agent thomas that he was free to leave any time. everything was legal. lead agent birmingham, watching seth on a monitor, simply ignored the commotion outside. >> i did get information that they were wanting to get in. and wanting to come in and tell seth to stop. >> reporter: which would shut you guys right down. >> seth is an adult. and he has the sole obligation to invoke his right to remain silent or his right to an attorney. and no one stopped him from doin' that. >> reporter: so thomas kept asking questions, and seth kept answering them. >> have you ever lied to lisa about rachel? >> no. she found out and that was, that was that. >> reporter: meanwhile, both dci agents birmingham and thomas had now learned more complete details from the scene from seth's best friend, the guy with the puppy. the friend, colton, had explained that seth was using his special tracphone as a steamy hotline. >> i know they were exchanging photos. >> reporter: did he tell you, "she sent me some topless pictures?" >> yes. >> reporter: did you see them? >> yes. >> reporter: armed with this information, agent thomas decided to show his cards and see what happened. >> we've talked to colton. did colton, uh, know about you texting rachel? >> mm-hmm. >> did you tell him about it? >> yeah. >> this is an ongoing investigation, and it's up to you to be honest. >> there's obviously more to this rachel thing. she was under the impression that lisa was going to be packing her stuff up and leaving. >> when? >> last night, today. >> reporter: he said he'd talked to rachel about him divorcing lisa as recently as the night before, at work. >> she just asked if i was going to go through with it and i said, "yeah." i mean, i shouldn't have lied, obviously. >> reporter: he admitted he liked rachel's attention but said he really was just stringing her along. >> we were having a baby. i wasn't going to leave her. i couldn't leave. >> reporter: lying to rachel was wrong, he said. but he claimed that lying earlier in the interview was a way to spare his grieving father-in-law, todd caldwell, the embarrassment. >> this is something i didn't want todd to find out. >> reporter: the interview had been going on close to four hours now, and agent birmingham was well aware that seth's father and a lawyer wanted to shut it down. agent thomas then took a break, leaving seth inside the room to stew. he met with birmingham, and they decided he had to go nuclear. >> reporter: be confrontational, because the clock is ticking. >> and if we're ever gonna be tough, now is the time. >> now is the time. >> here's the deal, okay? the facts right now, these case facts, show us you're responsible for killing your wife. >> no, no. i'm not, no. i can't kill my wife. i can't do it. what facts do you have that i killed her? >> listen, i've seen rachel, okay? i know what guys see when they see her because i see the same thing. okay? >> i'm telling you, if i wanted to be with rachel i would get a divorce. i would not kill my wife over something that small. you know what? right now i guess i don't give a -- what happens to me, okay? i know what happened, i know what you're trying to do. >> what am i trying to do? >> you're trying to get me upset and it's working. congratulations. >> reporter: upset at this hostile line of questioning, seth said he'd had enough. got up and, strangely, shook thomas's hand. >> appreciate it. >> reporter: and then he walked out. in the end, what did the investigators have? that seth lied about sex, but was it even that? all he admitted to was making out with rachel. and on the big question, he insisted, over and over again, that he did not kill lisa. even agent thomas expressed disappointment with the outcome of the marathon interview, nearly five hours long. you felt you'd come out of a 15-round fight? >> it was exhausting. felt somewhat like a failure, in some regards. >> reporter: why? >> we didn't get the full confession. >> reporter: maybe that's because seth didn't do it. agent thomas just didn't know. but the women in the caldwell family, without knowing any of seth's admissions about rachel, believed with 100% certainty that seth did not kill lisa. especially lisa's sister and seth's great friend, presley. >> i was never thinking that seth did it. >> reporter: only todd caldwell was no longer a true believer. the cop in him questioned why seth needed to lawyer up. his own investigative instincts also kicked in, though he'd asked his fellow deputies not to tell him anything until they were ready to make an arrest. and late on day one of the investigation, they weren't even close. >> i would say, at 10:00 on saturday night, may 26th, that neither seth nor brian tate were completely eliminated as suspects. >> reporter: at that time, investigators were meeting at the sheriff's department command center to take stock. they knew they had a husband with a possible girlfriend and a maybe crazy neighbor with a vendetta. but they also learned by that night there was a missing shotgun. what did it all mean? one piece of the puzzle falls into place. >> that was a huge thing in the case. >> it was. >> and another round of heart break for lisa's family. >> this has got to be more than your brain can absorb. >> definitely. when our daughter and her kids moved in with us... our bargain detergent couldn't keep up. turns out it's mostly water. so, we switched back to tide. one wash, stains are gone. daughter: slurping don't pay for water. pay for clean. it's got to be tide. special guest flo challenges the hand models to show off the ease of comparing rates with progressive's home quote explorer. international hand model jon-jon gets personal. your wayward pinky is grotesque. then a high stakes patty-cake battle royale ends in triumph. you have the upper hands! it's a race to the lowest rate, and so much more. only on "the upper hands." shh! i took mucinex dm for mye, phlegmy cough.h more. what about rob's dry cough? works on that too, and lasts 12 hours. 12 hours?! who studies that long? mucinex dm relieves wet and dry coughs. and still going for my best. even though i live with a higher risk of stroke due to afib... ...not caused by a heart valve problem. so if there's a better treatment than warfarin, i'm reaching for that. eliquis. eliquis is proven to reduce stroke risk better than warfarin. plus has significantly less major bleeding than warfarin. eliquis is fda-approved and has both. what's next? i'm on board. don't stop taking eliquis unless your doctor tells you to, as stopping increases your risk of having a stroke. eliquis can cause serious and in rare cases fatal bleeding. don't take eliquis if you have an artificial heart valve or abnormal bleeding. while taking eliquis, you may bruise more easily- -and it may take longer than usual for any bleeding to stop. seek immediate medical care for sudden signs of bleeding, like unusual bruising. eliquis may increase your bleeding risk if you take certain medicines. tell your doctor about all planned medical or dental procedures. ask your doctor about eliquis. and if your ability to afford... ...your medication has changed, we want to help. special guest flo challenges the hand models to show off the ease of comparing rates with progressive's home quote explorer. international hand model jon-jon gets personal. your wayward pinky is grotesque. then a high stakes patty-cake battle royale ends in triumph. you have the upper hands! it's a race to the lowest rate, and so much more. only on "the upper hands." >> reporter: it was sunday, the morning after lisa techel had been shot to death. but it wasn't a day of rest for the techels and caldwells. they had to discuss arrangements. one of the saddest words in the language is, arrangements. we have to make arrangements, it must have been unreal. >> yeah. >> i don't remember it. >> reporter: grief-stricken, todd decided to stay home by himself while the rest of his family and the techels met in a park. seth was there, but under instructions from his lawyer not to speak about the case. he shared an emotional moment with lisa's sisters and her mother, tracy. >> the first thing -- seth grabbed the girls and hugged the girls and said, "they think i did it." we all hugged seth, you know, told him we loved him. >> reporter: when investigators finished their forensic work inside the trailer, tracy, seth, and his parents went out there to retrieve some of lisa's things. >> it was very tough. i was just amazed, the way it looked. >> reporter: crime scene techs have been all over it, hadn't they? >> all over it. i guess i went into dad mode and tried to protect seth a little bit. and i -- i wanted to cover up the bed. >> reporter: what was your thinkin' there? >> i just didn't want him to see the blood. >> reporter: how was your boy dealin' with all this, in these hours after? >> i think he was just shocked. >> reporter: that sunday wasn't a day of rest for the men and women trying to solve the crime either. investigators were focusing on the murder weapon, and were working a lead on a 12-gauge mossberg shotgun. it belonged to seth's friend, lucas howell, who'd been rooming with seth and lisa and had just moved out. we showed lucas this photograph taken of seth at his home. if you look in the upper right-hand corner, lucas, it's the gun rack. is your mossberg in that rack? >> yes, it's the middle one. >> reporter: lucas talked to deputies about the gun on the day of the murder. >> i told 'em that i hadn't took it with me and it should be there. >> reporter: but his 12-gauge wasn't there when crime scene techs scoured the trailer. and cops knew another place it wasn't -- on the list of guns kept at the house that seth had written out for the dci agent. investigators felt certain the mossberg was used to kill lisa, but a big question remained. >> where is it? that's what we wanna know. where is the gun? >> reporter: that same sunday morning, a team began searching the big, beautiful piece of property where seth and lisa were starting married life and preparing to raise a family. deputy marty wonderlin, working his first-ever homicide case, was back at the scene. not too long into this sunday morning search, over here by this big old tree, what do you hear? >> i hear, "we've got it. you know, shotgun here." they were goin' nuts. >> reporter: there was the mossberg in the tall grass, about 20 yards from the back door of the trailer. boy, that was a huge development in that case. >> it was. i think everyone's, you know, mood doubled or tripled when they found that gun. >> reporter: ballistics would later match the mossberg with the slug that killed the pregnant lisa. investigators could fill in one big box on their checklist -- murder weapon. next, they worked on possible motives -- was it a neighbor with a vendetta or a husband lusting after another woman? state agent birmingham and deputy phillips decided to have a talk with seth's work friend, rachel. >> we interviewed her on tuesday, may 29th. >> there's no tricks here, someone has lost their life. actually two people have lost their life. >> reporter: over the course of two hours, birmingham and phillips peeled back the layers of rachel's relationship with seth. >> they were having, you know, kind of an ongoing relationship. there are sexually explicit text messages. there are pictures, sexually explicit pictures, sent back and forth. >> he kissed me, but it never led into anything else. he just used to tell me i love you. that's about it. >> reporter: it sounds like they were making out rather than having sex. >> yeah, yes. that's correct. >> he always used to tell me how pretty i was and how he'd like to be with me. but i always made it clear that he is married and has a wife, and he's having a baby, and i don't wreck families. >> reporter: rachel told the investigators the seth she knew couldn't be a murderer. >> would it surprise you if he did this? >> honestly? yes, it would. >> reporter: but seth was a suspect, and if he did fire that shotgun blast, that would place rachel at the heart of a murderous love triangle. >> i think that's why i feel so guilty, because i don't want it to be because of me. >> reporter: the next day, deputies phillips and wonderlin were back at the neighbor brian tate's house. >> deputy wonderlin and myself deputy phillips are pulling up here at the tate residence to re-interview mr. tate. >> reporter: this time, they asked him point blank about the murder of his neighbor. >> we're just trying to figure this all out, you know. did you have anything to do with lisa's death? >> no, i didn't. >> reporter: tate stuck to his alibi: home and asleep, after taking his medication. lead agent birmingham thought he was telling the truth and crossed brian tate off his suspect list. so you only had one suspect at this point. >> yeah, one suspect and only one suspect. >> reporter: that evening, lisa's loved ones gathered at a funeral home for the visitation. the turnout was impressive and included many of todd's friends in the sheriff's department. your fellow officers are there as they would be, you know, they-- you know, want to show respect. >> right. >> reporter: the mood inside was somber and uneasy. the caldwells gathered near lisa's coffin. the techels stayed in the back of the room. seth was there. his sister-in-law presley will never forget what happened next. >> he actually came up to me, kind of in the middle of it, he gave me a big ol' hug, and he said, "you will always be my little sister and i love you." and i was like, "i love you back." >> reporter: when the last visitor was gone, only the two families remained, still at opposite ends of the room. >> then i saw the two dci agents come in and sit down behind me, a couple rows behind seth and i. i said, "is this a personal visit or professional --" >> reporter: is this condolences or somethin' else, huh? >> yeah, and he said, "it's professional." >> reporter: marty wonderlin was there. >> we asked seth to, you know, come outside. and we did it quietly, i thought. >> reporter: and when they were outside, deputy wonderlin carried out his orders, he arrested his friend seth techel. a fellow deputy put the cuffs on him. they were lisa's cuffs, the ones she'd used as a reserve deputy. so this has gotta be just more than your brain can absorb. >> definitely, yeah. >> reporter: little sister, "i'll always love you," and now, he's going downtown, he's about to be charged. >> yep. i couldn't understand it. we wouldn't ever dream or ever understand that it could be him. >> reporter: seth's dream was to drive a sheriff's car as a deputy. but now the wannabe cop was cuffed, riding in the back seat, and about to be charged with the murder of his wife. seth techel goes on trial. but before it even starts, the prosecution suffers a major blow. >> bad for us, great for them. >> then a clue changes everything. >> i believe it to be the most compelling piece of evidence in the whole case. this is decision tech. find a stock based on your interests or what's trending. get real-time insights in your customized view of the market. it's smarter trading technology for smarter trading decisions. fidelity. we started by making the cloud easier to manage. but we didn't stop there. we made a cloud flexible enough to adapt to any size business. no matter what it does, or how it changes. and we kept going. so you only pay for what you use. because at dell technologies, we stop...at nothing. ♪ bec- with the ninja fooditos, intelligesmart xl grill.ing just pick your protein, select your doneness, and let the grill monitor your food. it also turns into an air fryer. bring outdoor grilling flavors indoors with the grill that grills for you. >> reporter: for lisa techel's family, it had been a heartbreaking, relentless week. thursday didn't promise to be any better. lisa's funeral was held at the first lutheran church in ottumwa. seven months earlier, todd caldwell was at the very same church, walking his daughter down the aisle on her wedding day. now, he'd return to lay her to rest. lisa was buried in her jailer's uniform. a special detail of officers served as pallbearers. law enforcement had come out to honor one of its own. >> lisa woulda thought, you know, "this is all for me? i was so proud. >> i should've been able to be there and -- and watch her become a mom. she was just a joy. >> reporter: mothers shouldn't bury daughters? >> never. never. >> reporter: after the funeral, the caldwell and techel families turned their attention to the upcoming murder trial of seth techel. lawyers started to plot strategy, with the neighbor, brian tate, expected to be right in the thick of it. tate's sister cheri says he never could shake the feeling that the authorities would come after him. >> he still feels like they're saying he's a murderer. brian had even seen in the paper that they were callin' him a crazy and deranged neighbor. it just devastated him. >> reporter: that summer, brian tate tumbled into a downward spiral and never recovered. he died in september 2012, just four months after lisa's murder. the coroner would think it was heart. >> yes. >> reporter: what's the family think it was? >> we think it was heart. a broken heart. >> reporter: and now prosecutors andy prosser and scott brown -- from the state's attorney general's office -- worried that a jury might think the deranged, deceased, neighbor did it. their plan had been to call tate as a witness. >> on the theory that the devil you know is always better than the devil you don't, we wanted the jury to see mr. tate. >> reporter: but now with a trial date approaching, prosecutors had lost a key witness. >> bad for us. good for them. it's great for them. >> reporter: the long-awaited murder trial of seth techel was in hometown ottumwa. >> ready for the jury, gentlemen? >> reporter: february 2013, can you see yourself going into the courthouse? >> yeah, i remember. >> reporter: what do you say to one another? >> we gotta stay strong. >> reporter: the caldwells never wanted to believe seth killed lisa. but, heading into trial, they were all now convinced that he did, even presley, once his staunchest supporter. >> there's really no other explanation for what has happened. >> when you left the techel residence, who was there? >> reporter: two prominent families, the caldwells and techels, once close in-laws, were now fiercely divided, camped on opposite sides of the courtroom. seth had pleaded not guilty. >> i was like, "just look at me, like, i wanna see kind of in your eyes, how you're doing," but he doesn't look at you. >> she was like my best friend. >> reporter: prosecutors called to the stand their emotional trump card. todd caldwell remembered his lisa. >> everyone would tell me how much lisa and i are alike, and i would just tell everybody that she's the best parts of me. >> reporter: the prosecution had the burden of proving the charges, first degree murder and nonconsensual termination of a pregnancy. what did you think your strongest fact was going forward, strongest part of your story for a jury? >> probably the most important single piece of evidence was the shotgun. >> reporter: ballistics showed this mossberg 12-gauge was the murder weapon, a firearm that seth kept inside his house, and only he had access to it that morning, prosecutors argued. >> no murderer who wants to kill lisa techel comes to the murder scene without the murder weapon. >> we argued the impossibility of his story. some unknown assailant breaks into his house and kills the wife that he says he's gonna leave. >> tyler batterson is our next witness. >> reporter: prosecutors called one of seth's young friends to show the jury, they said, just how deceptive and manipulative seth was. this witness was one of the boys, it turned out, behind all the vandalism across the fence. he testified he was just following seth's orders. >> he told us to go mess with his neighbor tate. >> reporter: how were you gonna mess with him? >> fill five gallon buckets full of dog manure and go dump 'em on his property. >> reporter: remember, seth had assured his father-in-law -- and the state agent who interviewed him -- the exact opposite. >> and i said, "i'm not messing with him. i'll make sure nobody else is." >> reporter: looking back, that incident was what turned todd against brian tate in the first place, fixing the idea in his mind that his kids' neighbor was a deranged, maybe dangerous crank. >> i'm goin' by what seth had told me about him. >> reporter: as for tate's complaint-calls with deputies, as captured on dashcam video, it became evidence for the prosecution. >> we feed the squirrels, birds and deer. >> we were hopeful that the jury would see brian tate as we saw him. >> reporter: and they saw him as an eccentric, but harmless man. certainly not a killer. then, at last, it was time for the state's star witness, rachel mcfarland -- the other woman -- to show up and tell her story. did you need the jury to like her? >> we needed the jury to believe her. >> reporter: rachel testified her relationship with seth started heating up in december, 2011, which was two months after seth got married. >> it became more sexual, asking me to send pictures. or, i don't know just showing off my body i guess. >> reporter: on may 20th, 2012, seth and rachel met at a nature preserve, where they took this selfie to remember their time together. >> i mean he kissed me, touched me. he said that we had everything in common and that he had tried working things out with lisa and things weren't working and i was exactly what he wanted. >> reporter: she said seth repeatedly told her he was going to divorce his wife. >> did he say he loved you? >> yes. >> reporter: but rachel was hedging her bets. she told seth she was also interested in a co-worker named brandon, who just happened to call her during her tryst with seth in the park. >> he just started getting really jealous. >> and so on the 20th when he learned that you were communicating with brandon, he said what? >> just give me two more weeks. >> did you ask him what he meant just give me two more weeks? >> yes, and he just repeated the same statement. >> reporter: six days later, lisa was murdered in her own bed. >> and here we have a motive that we can understand. love. the whole relationship with rachel was evidence that was like a countdown to lisa techel's death. >> reporter: but defense attorney steve gardner countered, arguing the motive of an affair falls flat without the essential element -- sex. >> seth techel was being accused of murdering his wife for an affair that he was hopin' to someday have. >> you never had intercourse with him. >> no. >> you've never had oral sex with him. >> no. >> never had your clothes off. >> no. >> and you kissed a few times. >> yes. >> is that a fair assessment of the extent of your romantic relationship with mr. techel. >> yes. >> reporter: the defense also didn't accept the state's take on the neighbor as a harmless eccentric. >> the most compelling evidence as to how this occurred involved the neighbor, mr. tate. he was mentally ill. >> i'm done talking to you. >> reporter: and, according to the defense, dangerous, too. the defense then hammered home the portrayal of the unpredictable neighbor by using todd's own complaint summary from that day. you're in the awkward situation of being their best witness. >> right. >> you believed he could become a danger. anyone who should respond to that residence again should use extreme caution. >> that is correct, i did. >> reporter: the defense theorized that tate entered the trailer through an unlocked door and shot lisa for revenge. the key defense evidence that suggested an intruder was a stray peanut butter- and-jelly sandwich, in a baggie, left on the back deck. >> there was a sandwich that would not have been there the night before that was there. >> reporter: critters should have devoured it, he argued. he told the jury it must have been the killer's snack. >> i believe it to be the most compelling piece of evidence in the whole case. >> reporter: it was now up to a jury to decide. but it wouldn't be easy. in the jury room deliberations and drama. >> he started pounding on the door, saying he wanted out of there, and we were in tears. medicare, listen up. the medicare enrollment deadline is only days away. with so many changes, do you know if your plan is still the right fit? having the wrong plan may cost you thousands of dollars out of pocket. and that's why i love healthmarkets, your insurance marketplace. with healthmarkets' fitscore, they compare thousands of plans from national insurance companies to find the right medicare plan that fits you. call or visit healthmarkets to find your fitscore today. in minutes, you can find out if your current plan is the right fit, and once you've let the fitscore do the work, sit back and enjoy not having to shop for insurance again. healthmarkets' fitscore forever technology will continuously scan the market for the best coverage at the best price. so you can shop once and save again and again and again. rest easy, knowing you'll have the right plan, at the right price, and the right fit for you. best of all, their services are completely free. does your plan have $0 copays, $0 deductibles, and $0 premium? if not, maybe it's not the right fit. does it include dental and vision coverage? well, if not, maybe it's not the right fit. how about hearing aid, glasses, and even telemedicine, at no additional cost? maybe there's a better fit for you. call healthmarkets now, or visit healthmarkets.com for your free fitscore. they can instantly compare thousands of medicare plans with all these benefits and more, including plans that may let you keep your doctor and save money. healthmarkets doesn't just work for one insurance company. they work to help you, and they do it all for free. having helped enroll americans in millions of policies, while earning an a-plus customer satisfaction rating from the better business bureau, you can trust healthmarkets. with the annual medicare enrollment deadline coming, go to healthmarkets.com, or call right now. your insurance marketplace. healthmarkets. find your fitscore and get your answers today to get the most out of medicare. call now. welcomeis that your home?o live. dun, dun ,dun. hold on, stop! you accessorize with a sloth? this is belt. [ chuckling ] great sash. oo-la la! here is what is handling. still time to prevent thanks ghi giving from being a superspreader event. by our count the u.s. reported more than 2,000 deaths yesterday, highest since july. today joe biden is in delaware, and he tweeted a video encouraging shared sacrifice. president trump tweeted falsely that the election was rigged. he is with family at the white house. now back to "dateline." >> reporter: back in the deliberation room, wrangling jurors in the seth techel murder trial were driving the case into a ditch. they stay out and they stay out and they stay out. what are the prosecutors telling you, todd? >> that there are some that are guilty and there's some that are not guilty, and they're just not agreein'. and i'm starting to get worried at that point. >> reporter: micah sheheen was on the jury. she said one holdout juror in particular was responsible for the stalemate. >> he started pounding on the door saying that he wanted out of there. and we were in tears. a lot of us because we knew that we were up against a wall, that nothing else could be done with this person. >> after weeks of testimony and three full days of deliberations, the seth techel murder trial came to a sudden conclusion today. >> reporter: it was all over. >> the motion for a mistrial is granted. >> reporter: the judge declared a mistrial because of a hung jury. hung jury? punch to the gut, andy? you ever have one? >> well, i never had one in almost 30 years. >> reporter: prosecutors immediately decided to retry the case. the vote had been ten to two for conviction. >> of course we're disappointed in what happened. >> reporter: the caldwells had lost a daughter and sister and, now, they couldn't even get the closure they desperately wanted. and they'd have to do it all over again. >> it's hard to know that you're gonna have to endure another one. >> reporter: a trial date was set for seven months later, october 2013. and trial number two would be heard in a new courthouse. there'd been a change of venue to the town of mt. pleasant. making it even tougher on the caldwells, the daily treks to court, lives disrupted. the new courtroom had a distinctive layout that put the caldwell family directly behind the defendant. >> he's literally sitting right in front of me like you are. >> reporter: which only made it more frustrating for presley who was still trying for any kind of connection to someone she once loved like a brother. >> i'm just staring at him, like, "just glance at me, do something," and he doesn't. >> reporter: and even more painful for the family was having to sit through -- again -- all that heart-breaking testimony, and raw crime scene photos of their lisa, and the unborn baby girl. >> reporter: other than the change of venue, seth techel's second murder trial played out as a carbon copy of the first. same lawyers, same judge, same arguments. a replay of two opposing theories -- brian tate, the "other suspect," versus seth techel, the husband with the "other woman." rachel mcfarland was, again, the prosecution's star witness. >> here on may 4th of 2012, he sent you a message with a picture of his, his own smiling face saying, "miss you bella." >> mm-hmm. >> is that a term of endearment that he called you, his bella. >> yes, yes. >> you sent him a picture of you in either a bikini or your bra and underwear. is that right? >> yes. >> and then he says, "well, wish me luck. i love you" at 10:51 p.m. on may 24 of 2012. what was he asking you to wish him well with? >> i believe that he was going to tell her that he wanted a divorce. >> reporter: two days later, lisa was dead. by now, her family had hardened opinions about rachel. >> i don't think too highly of her. i felt like she destroyed my sister's marriage and her life. >> reporter: todd, rachel, huh? >> actually, i'm, i'm maybe not the most popular view. i blame her for what part she had to play with seth but i think she's kinda been a victim as well. >> he's manic, he's up all the time. >> reporter: the defense offered the jury the same bogeyman as before. >> the defense went even harder at brian tate than they had the first time around. >> he could quickly become volatile and agitated. >> reporter: this time, the defense, over strenuous prosecution objections, got tate's psychiatrist to testify. he'd treated him near the end of his life in a hospital mental health unit. >> when you first saw him did you find him to be paranoid, paranoid delusional? >> yes, sir. >> and was there a general topic of delusion of which he was paranoid? >> he seemed to make reference that there were some governmental conspiracies affecting him. >> reporter: after three-weeks of trial, a second jury had seth techel's fate in its hands. and that's when things got deja vu all over again. the judge read a note from the foreman. >> we're not going to reach a verdict. what's next? todd, it's happening again. >> yep. and i'm thinking, "this is two months wortha trials and we're right back to the beginning." >> reporter: but the judge wasn't ready to give up. he told the jurors to keep trying. emotions in the open courtroom were raw, especially on the caldwell side. the jury couldn't help but hear it. >> presley and i were crying. we weren't crying uncontrollably or anything. but you could hear us sniffling a little. >> reporter: as the jury filed out, defense attorney steve gardner rose, to scold the spectators. stop the over-the-top outbursts, he said, or he'd demand a mistrial in fairness to his client. >> i do not desire this jury to be influenced by the public. >> reporter: now, it was the prosecutors turn to seethe. >> the defense is making this speech about the caldwell family trying to somehow influence the jury, which we thought was ludicrous, i squeezed andy's arm, and i said "i'll take this." >> to stand up here and suggest that anyone in the courtroom is trying or attempting to intentionally influence the jury is absolute nonsense. >> reporter: the courtroom started to settle down and clear. but seth remained at the defense table, his former father-in-law coiled behind him, ready to pounce. >> i was just praying, "please just let me stand here. >> reporter: for more than a minute, glaring, burning a hole in seth's back. if looks could kill. >> there's just kind of an urge to move forward. >> reporter: to jump the rail? >> yeah. god, please don't make me do that. just let me stand. >> reporter: what were you doin' in your mind? >> i don't really wanna even think of what i was doin' in my mind but i was -- i was wantin' to do somethin'. >> reporter: two hours later, the jurors returned. but nothing had changed. >> a mistrial is declared. >> reporter: unbelievable. veteran prosecutors who'd never had a hung jury before, were now o for 2. again, the state didn't hesitate. seth techel would go on trial for a third time. >> our intent is to retry it. that was an easy decision to make. >> reporter: even though the jury's vote was again in favor of conviction, this time nine to three -- lisa's family was starting to have its doubts. >> is there something that i'm just overlooking? like did he not do it? is there something that they just see and they're like -- he's not guilty? >> reporter: but just when they thought they couldn't suffer any more heartbreak, the caldwells would be devastated by new findings by a brand new defense team. >> i heard it about a week before the trial and it -- just like somebody hit me in the stomach. the defense comes out swinging. >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint, confession. vicks v easy to wear with soothing vicks vapors for her, for you, for the whole family. trusted soothing vapors, from vicks ...who takes care of yourself. so why wait to screen for colon cancer? because when caught in early stages, it's more treatable. i'm cologuard. i'm noninvasive and detect altered dna in your stool to find 92% of colon cancers... ...even in early stages. tell me more. it's for people 45 plus at average risk for colon cancer, not high risk. false positive and negative results may occur. ask your prescriber or an online prescriber if cologuard is right for you. i'll get on it! that's a step in the right direction. sofi made it so easy to pay off my student loan debt. ♪ they were able to give me a personal loan so i could pay off all of my credit cards. i got my mortgage through sofi and the whole process was so easy. ♪ choosing sofi was literally one of the best decisions i could have ever made because it gave me peace of mind. ♪ >> reporter: two families. two trials. and so far, no winners. but trial number three promised to be different, starting with a new defense team. >> the previous trials were not successes. and seth came dangerously close to being convicted in each of them. >> reporter: state-appointed defense lawyers roger owens and jake feuerhelm knew that, in two trials, 19 of 24 jurors had voted to convict seth techel. they didn't like those numbers, and decided to head in a different direction. >> we chose to focus on the sloppy work done by the law enforcement. there was absolutely no dna, fingerprint -- confession. >> reporter: feuerhelm would argue it was a botched investigation. why would crime scene techs do tests to match the slug to the murder weapon, but never check it for fingerprints or dna that might link it to the shooter? >> did you test the bullet that was in the chamber that killed this woman? no, we forgot, or we didn't do it. >> reporter: whoops. >> whoops. >> reporter: the new defense team had a new story to tell -- it was all a rush to judgment to blame seth, who'd been in jail ever since his arrest two years earlier. and there was another big strategic shift. they would soften the focus on the boogeyman of the first two trials -- brian tate. >> our conclusion was after listening to the tapes of mr. tate, that he wasn't the deranged person that they tried to portray him as being. >> the way he was speaking to law enforcement that afternoon would not seem like the person that would have walked into a trailer home at 5:00 in the morning and murdered his neighbor. >> reporter: the defense attorneys made a tactical decision. since recordings of tate didn't make him look like a dangerous killer, they would not show tapes of him to the jury. and they'd roll the dice, hoping the prosecutors wouldn't either. >> the caldwells and techels had been put through the wringer for more than two years, their once close relationship had frayed. and now the third trial was pushing everyone to the brink. it was an impossible situation, but somehow todd caldwell and doug techel managed to find a moment of grace. >> i went over to him and i just said, "doug, i want you to know that i think you're a great guy. i think you're a good person." >> reporter: did you really? >> "no matter how this turns out, i just want you to know that." and he said, "i think the same thing with you, todd." and i went to shake his hand and he just hugged me and we both just hugged. >> reporter: the two fathers then returned to opposite sides of a murder trial. july 2014, for the third time, the state of iowa versus seth techel. >> counsel, you ready for the jury? >> reporter: this time in davenport, three hours from the first courthouse in ottumwa. the prosecutors once again argued that seth's story defied logic. >> he would have to be the victim of one of the largest coincidences ever known. and that is he told his girlfriend that he left his wife. and a little less than 17 hours later, some unknown assailant breaks into his house and kills the wife that he is -- says he's gonna leave. >> with a weapon which he hasn't brought with him. >> correct. with a weapon which he hasn't brought with him. >> i had a mossberg model 500 shotgun. >> a 12 gauge. >> yes. >> reporter: and seth, prosecutors said, had easy access to the murder weapon, the shotgun that his friend lucas kept in seth's house. >> is that the 12 gauge mossberg shotgun that you left behind in the techel residence when you moved out in may of 2012? >> yes. >> reporter: and, the prosecutors argued, only seth had a motive. they said seth and rachel's steamy texts and cell phone photos played like a countdown to murder by seth. >> at 9:20 p.m. on the 24th, you ask him, do you really want to be with me? and he responds, "forever." >> right, yes. >> reporter: that's may 24th, two days before lisa's death, and in a follow-up text, rachel asked seth if he'd told his wife he wanted a divorce yet. >> and he responds, "well, we talked. i told her i wasn't happy, she got mad then sad, then i slept on the couch, so hello, mrs. resuscitator." >> correct. >> reporter: rachel told the jury that she and co-workers nicknamed seth "mr. resuscitator" because he was a volunteer firefighter who often bragged about his life-saving cpr heroics. >> so he was going to be mr. resuscitator and you were going to be mrs. resuscitator. >> yeah. >> reporter: then to drive home their contention that seth chose murder over divorce, prosecutors called a co-worker who'd been a confidante of seth's. >> i just expressed he just needed to either end his marriage or end it with rachel. >> and in saying that he should end his marriage with lisa techel, did he make any comment concerning child support? >> he asked me if i wanted to pay his child support. >> reporter: and then the witness recalled another remark seth made about lisa. >> he stated that it would be better off if she was in a car wreck and died. >> reporter: prosecutors hoped their third time would be the charm. but, the new defense attorneys would come at them with everything they had and that included explosive new evidence. this time, it was about lisa. >> found out the story that there was a guy, co-worker. >> was there another man in lisa's life? we'd love some help with laundry. spray and scrub anything with a stain. wash the really dirty clothes separately. tide pods with upgraded 4-in-1 technology unleash a foolproof clean in one step. aww, you did the laundry! it's got to be tide. ojust one jar of olay retinol24? hydrates better than the $100 retinol cream. for smooth, bright skin or your money back. olay. face anything. and try new retinol24 max. ♪ ♪ [ engines revving ] ♪ it's amazing to see them in the wild like th-- shhh. [ engine revs ] for those who were born to ride, there's progressive. it's velveeta shells & cheese versus the other guys. ♪ clearly, velveeta melts creamier. to save you up to 60%. these are all great. and when you get a big deal... ♪ ...you feel like a big deal. ♪ priceline. every trip is a big deal. >> reporter: from the day lisa techel was murdered, brian tate had been targeted as a suspect. >> go get him. get him. now. >> reporter: and he'd been exploited by seth's defense ever since. >> the question that you will have to consider is whether or not the state has proven that seth techel did it. >> reporter: new defense attorneys roger owens and jake feuerhelm had a completely different strategy. they barely mentioned tate's name. rachel, offered as seth's motive for murder in earlier trials, was also minimized this time. >> good afternoon, miss mcfarland. >> hi. >> reporter: in cross-examination, rachel was on the stand for a scant seven minutes. tick tock, there's the message on thursday. mr. and mrs. resuscitator, blue skies ahead. we're a couple. what do you do with something like that? >> i tried to be as straightforward as i could with the jury. who in the world is going to murder their wife to facilitate a relationship that hasn't even turned sexual? >> you're not having any sex with this man right? >> correct. >> and the only time you'd actually seen him in person, in your whole entire life, outside of work, was four or five times. >> correct. >> i have no further questions. >> what we wanted the jury to think about her is that you're gonna shoot your wife for this? >> reporter: attorneys feuerhelm and owens then went on the attack, characterizing the work of investigators as woefully shoddy. >> the ayes have them -- inconsistent, incompetent, incomplete. >> reporter: the new defense thrust was on what the investigators did not do. this state criminalist had to admit they did not test for gunshot residue on seth techel. >> how many times do you think you testified in criminal trials that gunshot residue was evidence of a crime? >> a lot. >> but in this case, no, we can't argue it because we don't have it. >> yeah exactly, we'll never know. >> never know. >> reporter: and the defense said it was even more shocking that this state expert had to make a similar admission about the fatal shotgun shell. >> this is the shell that killed lisa techel. >> yes. >> the very shell that killed this woman was never examined by the state. they just said, "we -- we forgot to do it." >> reporter: but the centerpiece of the defense case against the cops was something else they didn't do. they'd been so busy investigating seth, who'd been behind bars since his arrest two years before, that they never really paid attention to lisa. the new defense team would change all that, starting with her cell phone and the secrets it held. you found out the story told by the phone? that there was this guy -- co-worker? >> right. >> reporter: it was a bombshell. lisa was having an affair with a fellow jailer. >> lisa's lover was a married man, a father of four. >> reporter: and this is not making out in the back of the car? >> no. he thought he could even be the father of her -- of the child. he thought that. >> reporter: so they called lisa's lover, jason tinnes, to the stand. >> back in may 2012, did you know lisa techel? >> yes i did. >> reporter: jason testified that the affair started before lisa married seth and ended just weeks before her murder. >> mr. tinnes at some point did your relationship with lisa techel become sexual? >> yes, it did. >> now when we talk about a sexual relationship we're not talking about texting, are we? >> no, sir. >> we're talking about actual sexual intercourse correct? >> yes, sir. >> reporter: for lisa's father, the revelation that his daughter had a lover was the cruelest blow yet. >> the first emotion i had is, "why? why, lisa?" you know? and my second thought is, "i don't wanna tell amy 'cause i know she's not gonna be happy." >> reporter: does it taint your memory at all? >> really, what it did for me more than anything is, i have so many more questions that i'll never get the chance to ask her. i mean, i love lisa and she was a human being and she made mistakes. >> reporter: the graphic testimony about lisa's affair, and how police overlooked it, fit perfectly with the defense's theme of a botched investigation and a rush to judgment against seth. >> here's a legitimate suspect that should have been investigated. >> reporter: investigators never spoke to jason while they were building their case against seth. prosecutors finally contacted him just days before the third trial started. >> so between may of 2012 and sometime in june of 2014, no one talked to you, you didn't talk to anyone about this at all. >> no, sir. >> reporter: but prosecutors fought back. jason had an alibi witness -- his wife. they called her to the stand. >> do you have any memory miss tinnes as to the whereabouts of your husband on may 26, 2012 at approximately 5:00 a.m.? >> he was sleeping with me at our house. >> reporter: and dna testing on jason, done right before trial, also proved he was not the father of lisa's baby. but the defense still believed that raising the story of lisa's affair, and how police never uncovered it, would give jurors reasonable doubt about the entire investigation. 'cause this is the big part of your case in trial three. jurors, you're seein' some really shabby police work here in terms of investigation? >> it fell right into our theme, to our theory of the case. >> reporter: testimony in the >> reporter: testimony in the third trial, streamlined by both sides, took half the time the others did. that was another part of the new defense team's revised strategy. there'd already been five holdout jurors in the previous two trials. now todd caldwell worried that the new defense team had produced a cloud of even more reasonable doubt. >> you kind of think, okay, if i was on this side, that's kind of how i would have handled it. they're doing a pretty good job. and i'm convinced it's going to be another hung jury. why wouldn't it be? >> coming up -- todd, and just about everyone else, are in for a surprise. >> has this jury reached a verdict? ict? or what's trendi. get real-time insights in your customized view of the market. it's smarter trading technology for smarter trading decisions. fidelity. - with the ninja foodito intelligesmart xl grill.ing just pick your protein, select your doneness, and let the grill monitor your food. it also turns into an air fryer. bring outdoor grilling flavors indoors with the grill that grills for you. if you experience bladder leaks, you shouldn't have to sacrifice discretion for protection. try always discreet. the unique design features protective leakguards, which help prevent leaks where they happen most and an absorbent material that turns liquid into gel, for up to 100% leak free protection. the shapewear design provides a close and seamless fit, to ensure total discretion. choose the solution that keeps you drier. try always discreet underwear, with a money back guarantee. brand power. helping you buy better. i have moderate to severe plaque psoriasis. now, there's skyrizi. 3 out of 4 people achieved 90% clearer skin at 4 months after just 2 doses. skyrizi may increase your risk of infections and lower your ability to fight them. before treatment your doctor should check you for infections and tuberculosis. tell your doctor if you have an infection or symptoms such as fevers, sweats, chills, muscle aches or coughs, or if you plan to or recently received a vaccine. ♪ nothing is everything ask your dermatologist about skyrizi. >> reporter: july 24th, 2014. after two agonizing stalemates, this time things were different. as seth techel walked into the courtroom and sat down his face showed no expression, no hint of emotion. he didn't glance in any direction. not at his family, and certainly not at todd, his former father-in-law. this is the young guy you used to clap on the back and say, "i love you." >> yep. "just take care of her. that's all i ask." >> reporter: but todd was staring directly at seth, hoping to find something, anything. now, the moment was at hand. >> has this jury reached a verdict? >> it has. >> reporter: the judge asked the court attendant to read the verdict. lisa's mother could barely contain her emotions. lisa's sister, a bundle of nerves. >> count one -- we the jury find the defendant seth andrew techel guilty of murder in the first degree. signed by the head juror. count two -- non-consensual termination of human pregnancy, guilty. >> reporter: the justice system had finally spoken for lisa and unborn zoey. and then you hear the words? what do you see? >> i hear the words guilty. and i see nothing, not one single emotion from his face. >> reporter: the jurors had taken four hours to convict. on their way out, several reached across to shake tracy's hand. presley still had one big question. >> i would love to ask him why. there's seth before may 26, and then there's seth from may 26th on. and it's almost like i don't know who that is. >> reporter: seth's parents tried to fight back tears. >> it's heartbreaking. >> reporter: on the caldwell side, tears of joy and displays of overwhelming relief. there were hugs and more hugs, more than two years of pent-up emotions finally coming out. the caldwells then walked across the aisle. the two moms embraced, united in tragedy. >> we know this family. i know it's not doug and lorraine's fault. it's not their family's fault that any of this happened. todd searched out doug. only three years before, they were all celebrating their kids' wedding together. doug and lorraine still support their son and say he didn't do what he's now convicted of doing. do you have a whisper of doubt, either of you? >> no, sir. >> none whatsoever. i never have and i never will. >> everybody's a loser. nobody wins. but i will say this. i think lisa knows somewhere that the system that she wanted to be a part of worked. >> reporter: the caldwells and techels weren't the only ones with a stake in the verdict. brian tate's sister cheri had been waiting for this moment, too. >> i start crying. it wasn't tears of sorrow. it was tears of joy. they had finally gotten this s.o.b. i hope he rots in prison. >> reporter: todd still carries the burden of helping to pin the blame on tate in those awful moments after lisa's murder. >> i can never tell the family how sorry i am that they had to go through what they had to. we're going to have the last word on brian tate. this is an innocent guy that was made a victim by seth. >> all rise. >> reporter: a sentencing hearing was held in september 2014. the caldwells were given a chance to address the court, but talked directly to seth. >> you know how close lisa and i was. and you know what you took from me. out of everybody in this room, you know. >> reporter: presley, lisa's sister, walked up to take her turn. during all three trials, she'd desperately tried to make eye contact with seth. >> seth was my best friend, my brother, who i loved so much. >> reporter: now, she finally got what she wanted. as she spoke, she looked straight at him. and for the first time seth stared right back at her. >> i'm going to leave you with one final thought, that i'm no longer your sister and i no longer love you. >> reporter: and then the judge handed down the sentence. life in prison with no possibility of parole. when it was finally all over, todd went to the cemetery for a private moment with his oldest daughter. >> i went out there and i just told her that we did it and she could be proud of everybody. >> reporter: todd's been back many times since. lisa's grave is a special, deeply personal place for him. he designed her headstone. what are the figures in it, todd? >> the first thing i would do when i started like sketching it is, i would just draw a heart out. for some reason in my head, it should be in the shape of a heart. the second thing i would put in there is a mother holding a baby. and lisa and i had this thing that we would say to each other. we texted to each other and everything. it's from, "the notebook," movie and it's -- we've always said, "if you're a bird, i'm a bird." you know, i mean, whatever -- whew. "whatever you are, i am." so in the hair of this, i made two birds in there. by the time i got done with it, you know, we all loved it. and it's kind of just, kind of bonded like, hey, this is part of lisa now. >> > she was the love of my life. always. >> she was a very, very kind person. >> then she vanished. >> i called the police. something was wrong. >> and something was. no leads, no clues, no progress. >> i said we got to get moving. >> enter the a-team, a band of to
you guys? >> she was interested in the same things that all of us were. she liked to go fishing. she liked to go hunting. she liked to shoot guns. >> was she okay? >> better than seth. >> sounds like you would have been happy if she were your girlfriend? >> seth was lucky. >> lucky for sure. but seth knew it was time to settle down and get a real job. like lisa, he was drawn to uniformed service. he signed on as a volunteer firefighter and drew a paycheck as a security guard. but his father-in-law todd was helping him get a higher rung on the ladder with a soon to start job as a jailer for the sheriffs. >> they were very close. todd was a big influence on seth. that's why i think he went into law enforcement. >> a new job, a young marriage, and now more changes for seth. he was going to be a father. they picked a name for the unborn girl, zoe marie. in may 2012, they were halfway through the pregnancy. seth and lisa, a baby on the way, were starting out their married life in this humble little trailer. it was a gift from his dad purchased on a beautiful piece of property. it
hiding something. what was the story that you told them? >> i told them that seth had a track phone. >> so kind of a secret phone, huh? >> yeah. >> when "dateline" continues. hen "dateline" continues hen "dateline" continues feeling better? on top of the worlddddd!!! before advil. advil targets pain at the source of inflammation. when pain comes for you, come back fast with advil liqui-gels. kayaking is my thing. running is awesome. but her moderate to severe eczema would make her skin so uncomfortable. now i'm staying ahead of it. dupixent helps heal your skin from within. so, they can have clearer skin and less itch. serious allergic reactions can occur that can be severe. tell your doctor about new or worsening eye problems such as eye pain or vision changes including blurred vision, joint aches and pain, or a parasitic infection. don't change or stop asthma medicines without talking to your doctor. ask your doctor about dupixent. icy hot.
prepared that this could be our suspect. >> so, only eight hours after his pregnant wife was murdered, seth's formal interview with dci agent thomas got under way. >> you can just call me chris, i guess. you're free to go out of here at anytime. >> in the interview room, agent thomas was in the white shirt, back to the camera. to put seth more at ease, a deputy familiar to him sat in. it started out routinely. >> you have a job? >> currently, i work at job corps as security, but i'm actually next month coming to work here in the jail. >> seth had already given his account twice to deputies at the scene, but this would be his first time on videotape. his story begins somewhere around 5:00 a. m. >> exactly. >> i turned the shower on. i wasn't in there for more than five minutes and i heard this loud noise. >> he said he thought it might be a gunshot so he jumped out of the shower to check on lisa. he heard her moaning then made out another sound, coming from possibly the back deck. he said