you just wonder how this could happen. it seems very surreal. >> a quiet night at home shattered by a gunshot. >> she came out of the shower and i heard a pop. and there's blood. >> a young life dying on the floor. >> she wasn't talking at all. i'm asking, what happened here? >> i was utterly confuse. >> so many different stories about what might have happened. >> he said many things that night. >> maybe someone shot something at the house. >> at one point he said it was 80% suicide. >> police had their own theory. >> i thought, oh, man, there's something going on here. >> we don't see a lot of women commit suicide naked. >> his stories weren't adding up. >> but something else was it adding up either. a key piece of evidence. >> we went to the house and we walked in and we think, ha. >> would in the stake in measurement send an innocent man to prison? or free a guilty one? >> we thought it was over. we thought this was settled. >> one suspect, so many stories, only one of them could be true. >> something is going to break. and when it does, the truth is going to be known. >> hello and welcome to "dateline". heidy wagner and conrad truman had a powerful connection. a deep love envied by others. then one fateful night, the young couple was jolted by unforeseen tragedy when heidy was killed by a single john gunshot to the head. in the aftermath, fingers were pointed. but where the aimed at an innocent man? here's josh mankiewicz with "as night fell". >> they seem so icongueous. the soaring majesty of utah's wasatch mountains and the story of a beautiful woman, struck down in her youth. it was a lot of things. tragic. crushing. stunning. but was it an accident? or a suicide? or a murder? police felt they knew. but as most cops who will tell you, both the evidence and the jury have their own stories to tell. and the answers are not always so clear. certainly, that is true for this story. and quite possibly for the woman at its heart. her name? heidy wagner. >> as a baby, she was favored. everybody loved her. she could do no wrong. >> autumn was one of heidy's four sisters. >> she was just special. she would walk into the room and she was ready for that good time. >> heidy grew up with no fewer than seven older siblings. tell me about her growing up? >> she was a fun loving girl. she was rather shy, though. so heidy seemed like an appropriate name. >> heidy's mom, janet. >> the family was boisterous. she's kind of get embarrassed easily. she hide her face. [laughs] >> as heidy gold or, she was still cute and bubbly. but make no mistake, heidy was no pushover. >> she was kind of intimidating, actually. for being so small you wouldn't think so. >> at just 20, heidy started working in the not entirely feminine gas and chemical industry just outside salt lake city. sandi sanchez was one of heidy 's coworkers. >> we worked with hazardous chemicals and gases. [laughs] crazy things you would expect a couple of girls to want to do. >> seemed heidy to thrive in a workplace that favored hard hats over heels. >> it was dangerous if you didn't follow the rules. in fact, quote from heidy, everything is dangerous. it's just what will kill you the quickest. >> two sandi sanchez, it heidy came more than just a coworker. >> i considered her my best friend. she was a person that you knew would never stab you in the back. she was a person you knew would always have your. back >> in person, she could be both. sweet and salty. and that caught the attention of one of her colleagues, 25 -year-old, conrad truman. >> i noticed her first in the hallway. >> what did you think? >> i thought she was cute. and i noticed her hard hat and they had a little personality stickers. and her said, it's all about me, deal with it. i was kind of thinking, this girl is kind of a feisty girl. >> soon, conrad asked heidy out on a date. >> i'm not that type usually. i don't get super serious. but it was almost like we were inseparable after. that >> it was that first night? >> yeah, yeah. >> this tough girl even shared conrad's interest in guns. >> we would go to the range, shooting at the hills. >> and she knew how to handle a handgun? >> yes. >> one year into their courtship, conrad decided to pop the question. in true utah form, he chose a mountain on which to do. it she have any idea was coming? >> no. so, i got on one knee and i asked her and i started bowling. and she just said yes, right off the bat. >>conrad's colette couldn't believe it when her little brother first introduced heidy to the family. >> i was actually really surprised when i first met her. like, how did he land that girl? they just seemed to be such a great match. >> you saw love and chemistry there? >> oh, it was almost awkward. they were definitely unenviable couple. >> another year later, came the wedding. >> it was amazing. we went on a lift, chairlift. and then all of the guests went down these slides. so, it was just so them. they said their vows and he's kind of doing this champion pose. like he was just, everything was right with the world. >> the enviable couple was just starting out. with a future as bright as their smiles. until that is, a sunday evening in september, 2012. three years after the truman were married. tell me about that day? >> that day was just like any other day. >> as night fell, heidy decided to take a bath. conrad said he went to the kitchen to get something to eat. as he faked himself a sandwich, he said he heard a noise coming from the direction of the bathroom. >> it was like the new year's poppers or the halloween poppers. where you can pull too strings or you can pull one. and confetti and stuff come out. >> that's when conrad said he turned and saw heidy standing there in the holy, naked. >> she wasn't talking. she was not talking at all. she was coughing. she was heaving. >> she was bleeding? >> she was bleeding out of her mouth and nose. i needed to call 9-1-1 immediately. >> 9-1-1. what is your emergency? >> orem, utah. come quick! >> an unimaginable shocking scene. heidy on the kitchen floor in a pool of her own blood. on conrad the phone, pleading for help. >> there's so much blood. if you don't get here right now, she's going to die. i don't know what happened. i really don't know what happened. oh, my god. >> it was bad to begin with and it got so much worse. >> as you will learn, truer words may never have been spoken. >> what happened in that house? coming up -- >> i'm asking conrad what's going on. he said, i don't know what happened. everything was just different answers. different theories. different little things. >> a search for answers and a race to save heidy. >> this is not happening. this is really not happening. >> when "dateline" continues. across bipolar depression. unlike some medicines that only treat bipolar i, caplyta treats both bipolar i and ii depression. and in clinical trials, movement disorders and weight gain were not common. call your doctor about sudden mood changes, behaviors, or suicidal thoughts. antidepressants may increase these risks in young adults. elderly dementia patients have increased risk of death or stroke. report fever, confusion, stiff or uncontrollable muscle movements which may be life threatening or permanent. these aren't all the serious side effects. caplyta can help you let in the lyte. ask your doctor about caplyta. find savings and support at caplyta.com. for my best skin, it's olay. better than a basic moisturizer olay starts working day 1 to visibly smooth and firm for a lifted look in one month, skin looks up to 10 years younger results you can see, in one jar olay the power goes out and we still have wifi results you can see, to do our homework. and that's a good thing? great in my book! who are you? no power? no problem. introducing storm-ready wifi. now you can stay reliably connected through power outages with unlimited cellular data and up to 4 hours of battery back-up to keep you online. only from xfinity. >> something was wrong at the home of the xfinity 10g network. truman house. >> she came out of the shower and i heard a pop. and there's blood. and she's in blood. >> i have officers and paramedics on the way. okay? >> the 9-1-1 call came into the orem, utah, police but department at about 11 pm. that september night back in 2012. >> we got a call of a gunshot wound or some sort of injury. >> sergeant bill crook went to the truman home. >> so we all rushed to our cars and hit that direction with lights and cyrene's. >> on the other end of the phone was conrad, kneeling on his kitchen floor, covered in blood. and consumed by panic. >> it was devastating. it was a nightmare. you can't even explain it. >> with one hand he held the phone. with the other, his bleeding wife. >> it was so hard when it's your loved one like that. i had no -- i just did the best i could to try to keep her breathing. >> by then, conrad said he realized heidy had been shot in the head. >> when you went to heidy did you see a gun? >> no. >> he remembered the pop he had heard and wondered if a stray bullet might have come through the bathroom window and hit heidy. >> i was trying to think of the noise and how it was it very loud. and maybe someone could have shot something at the house. >> it seemed far fetched. but he said, neighborhood vandals had recently been shooting the back of his house with paintballs. >> i was utterly confused. within minutes sgt. crook arrived, conrad i now had moved to the director of his home to weigh from down. >> he had blood on his hands. and he was screaming and shreaking. >> lead conrad the sergeant through the front door, up the stairs, and then it was a scene straight from a horror movie. >> i could see heidy laying there. she was naked. blood everywhere. right at the top of the stairs was a horrific scene. >> what is conrad doing? >> well, he's screaming and he's yelling. and >> as as these police photos make clear, covered in blood. >> i'm asking him, conrad what's going on? what's happened here? >> he said she was in the bathroom, i don't know what happened. everything was just different answers and different theories. different little things. >> right away, sgt. crook went to check one of those theories. a stray bullet. perhaps coming through the bathroom window. >> the window is closed. there is no bullet hole. >> nothing to indicate anybody but he fired a shot? >> that's correct. >> he returned to the kitchen and that's when he discovered a gun. lying on the kitchen floor. what did you think had happened? >> honestly, i didn't know. was this an accident? and attempted suicide? or something far more sinister? at least for now those answers would have to wait. heidy with clinging to life. >> my focus at that time was honestly to help heidy. >> paramedics took heidy to a nearby hospital. conrad followed in a police cruiser. a dash cam recorded the absolute desperation in his voice. >> this is not happening. this is really not happening. i really don't understand any of this. this is so crazy. >> about an hour after conrad arrived. hospital staff delivered the devastating news. heidy wagner truman could not be saved. >> it was pain. it is misery. it was why? how? >> in a neighboring town, heidy's mother, janet, would soon agonize over those very same questions. it was after midnight when two police officers came to her door. what must that be like? >> the most horrendous thing ever. and i would never want anybody to have to feel that. that pain, that agony of knowing that your daughter, for whatever reason is gone. is gone. >> the officers wouldn't give it janet any details. only where her daughter had been taken. >> i'm driving down to the hospital and i make a comment to my daughter, i go, you know, autumn, as hard it is that we lost heidy, we're going to have to be supporting conrad. because he must be overwhelmed with grief. >> conrad's sister colette was thinking the same thing as she raced to the hospital. what kind of condition was your brother in? >> he was just a total wreck. just absolutely hysterical. didn't know how it could've happened. >> no one did. but back at the truman home, sgt. crook had started analyzing the evidence. and was already developing a theory. >> i thought, oh, man. there's something going on here. >> you had a feeling? >> i had a feeling. yes. it wasn't just me. everybody was looking around like there is something wrong here. we needed to check it. >> coming up -- was a an accident, suicide? >> she's completely naked. we don't see a lot of women commit suicide naked. that's not normal. >> or something else? >> i felt like they thought i did something. >> when "dateline" continues. fda-approved rsv vaccine. arexvy is used to prevent lower respiratory disease from rsv in people sixty years and older. rsv can severely affect the lungs and lower airways. arexvy is proven to be over 82% effective in preventing lower respiratory disease from rsv and over 94% effective in those with these health conditions. ( ♪♪ ) arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache, and joint pain. rsv can be serious. talk to your doctor or pharmacist about arexvy today. rsv? make it arexvy. ( ♪♪ ) >> as the sun inched above utah 's wasatch mountains, questions swirled at their base. how did heidy truman wind up on her kitchen floor, shot in the head? for sure, police were wondering about her husband. after all, conrad truman was in the house when heidy was shot. and there was no evidence of an intruder. >> i felt like they thought i did something. >> soon after he arrived at the scene, sergeant bill crook did begin to have his suspicions. >> were telling him, comrade back off. and he wouldn't. >> he was what? moving around? keeping paramedics from being there? >> yes, sir. >> there were other scenarios that needed to be explored like accident and suicide. that's when detective tom wallace came in. >> there'd been a number of theories. we obviously are going to exhaust them. that's going to happen. the medical examiner did not make wallace's job any easier. his preliminary finding, heidy's manner of death could not be determined. so, wallace tackled each theory one by one. accident seemed to hard to believe. thanks to conrad, heidy had firearms experience. can you think of any way could've been an accident? >> no. heidy would it have been so careless. >> so, what about suicide? >> she's completely naked. we don't see a lot of women that commit suicide naked. that's not common. >> did you find anybody that heidy had spoken to about suicide, or about being depressed? >> no. >> neither heidy's mother janet nor her sister autumn, could imagine heidy even thinking about taking her own life. >> heidy would never do that, in fact she was against that. she had a friend who committed suicide and she thought it was selfish and in her words, dumb. >> heidy ever tell you she was depressed? >> no. >> ever act depressed? >> no. she was probably one of my happiest, most upbeat kids. >> that left wallace with homicide. and it put conrad back in the police crosshairs. wallace decided to speak to the officers first on the scene about their experience with conrad. >> everyone felt his behavior was odd. >> he's yelling but it's a violent yelling. he's like, if you don't save her, i'm going to (bleep) kill you. >> crook found those threat so alarming, he took out his phone to require them. >> you are going to (bleep) die. everyone is in your life is gonna (bleep) die. >> it could be the way this guy reacts to trauma. but i'm telling you, it was a red flag at those times. >> also red flag, conrad was drunk. he admitted he and heidy had been drinking earlier that night. >> i can see in his eyes, the redness. >> red flag number three, conrad told crook he and heidy had been arguing. a minor dustup, he said. no big deal. but enough for heidy to draw a bath and asked to be left alone. >> she went and locked herself in the bathroom and then he details how he picked the lock and went in the bathroom. and then she kicked him out. to me, that's another -- it's just more proof of there was an argument. a bigger argument. >> as for the location of the gun itself, that too was suspicious. >> that gun is how far from heidi? >> i would say eight feet, ten feet, maybe. it's far enough away that it was not a normal, if she shoots herself and fall to the ground type of thing. >> later that morning, police ask conrad the to come to the station for more questioning. >> they can say whatever they want, i did not hurt my wife. and i know that. bottom of my heart, i did not hurt my wife. >> heidy's family thought otherwise. after finally learning from the police the details of how heidy died. >> the minute i heard how she died, i knew he did it. >> it sounds like he had a temper and he is very intoxicated. and he did something that perhaps he didn't plan? i just knew he did it. >> detective wallace next poured over conrad's statements to police about what happened that night. as wallace saw it, conrad's story went like this. conrad was in the kitchen, heidy was in the bathroom. at some point, conrad heard a pop and when he turned, he saw heidy standing somewhere between the kitchen and the bathroom hallway, bleeding. >> and he either runs over to catch her, or she falls down. >> wallace then went back to the truman home, making detailed measurements of the kitchen and surrounding rooms. he wanted to see if conrad's story checked out. his conclusion, it did not. >> her body is at the top of the staircase. it doesn't add up that she would've traveled the distance that he is saying she would have gone, and then fallen at that location. >> it was hard for to wallace believe heidy could have traveled from the bathroom to the top of the stairs, after sustaining such a severe head wound. >> she would've fallen immediately to the ground. >> shared wallace his findings with assistant district attorney craig johnson. johnson agreed. everything pointed to conrad. why would conrad want to kill his wife? >> under the circumstances, i'd say the motive was just based on that heat of passion. argument that they were having. alcohol, a fight, and a gun, that is where we got murder. >> at the same time, johnson was still reluctant to press charges. remember, the states own medical examiner couldn't say whether heidy's death was a homicide. and johnson knew that would be a huge hurdle in court. >> based on my experience, courts with juries, and medical examiners carry lot of weight. so, johnson and wallace showed the m. e. a 96-page powerpoint presentation of all their evidence. including those measurements. hoping something would sway him. the presentation worked. the medical examiner changed his ruling. two homicide. it sounds like one of the things that got the medical examiner to move from any conclusive to homicide, was the measurements of the crime scene suggested that her body was too far from mr. truman said she had been shot. >> exactly. >> so, after a ten month investigation, the orem police department and the da's office arrested conrad truman. and charged him with his wife's murder. >> my mom called me and i fell to the ground, crying and so happy that he was finally behind bars. >> going into trial, what did you think? >> i thought we had a strong circumstantial case. >> at trial, the prosecution argued domestic violence ending in homicide. the defense? self inflicted gunshot wound. the jury sided with the state. conrad truman was convicted of heidy's murder. >> it was like, finally, got him. finally got him. >> and as far as you knew, that was it? >> that was it. >> did you think that was it? >> i did. >> but if you think that was it, well, then you haven't been watching enough