put something on facebook. diana is one of my oldest friends. >> i couldn't believe it. it still does not seem real. >> the wedding was in the woods. >> a nice outdoor forest wedding. >> a few years later, the marriage was in shambles. >> she wanted a clean divorce. >> a call out of the blue. >> they were going to meet? >> yes. >> did they find the shooter? >> vanished. >> who was this mystery man on a midnight mission? >> a but everything you would need to murder someone. >> it was a gunman police and maybe even you already know. >> i had seen dateline previously. >> someone was hiding a secret. >> where there's smoke there's fire. >> she started crying and said it's all true. >> a conspiracy to kill his caught on camera. >> when we open that email and saw that video, we were like, oh, my gosh. >> a shot in the dark and stunner in court. >> every once in a while we get a doozy and this was one of them . hello and welcome to dateline. diana and her husband were living the california dream. both were smart, outdoorsy types and the couple had welcomed a beautiful baby boy. then, it took a turn. not toward happily ever after but somewhere much darker. a call from a stranger would send one of them down an isolator road to retrieve a mysterious package. what was behind the secret admission and who would set it off? here is andrea canning with the night to the new moon. >> it was dark when it happen. so dark, strontium or's have a name for it. the night of the new moon. when the moon, the sun and the earth are in alignment and the lunar cycle begins anew. some look at a new moon is a time of rebirth, a fresh start. if only the people we trust on earth were as dependable as the night sky. >> there's a guy lying down like a sniper. he shot at us six or seven times. >> carlsbad, affluent seaside community in northern san diego county. a tourist haven known for beaches, surfing, and breathtaking views. this paradise became home to a woman named diana lovejoy. >> she's funny and silly and smart. really easy to talk to. >> sarah became fast friends with diana when they met in the six grade. >> through high school we would write to larry's notes to each other. still paid attention in class. >> of course. >> of course. we would challenge each other, the first sentence of a romance novel. >> she said diana had a gift for creative writing as well as music. something sarah, a professional bassoonist, know something about. >> she was a fantastic piano player. >> you shared a love of music. >> yeah, we did. we were in marching band together. it was fun. >> she had a schedule. she would wake up. >> jennifer was her college roommate. >> she was extremely discipline. >> diana was passionate about staying fit. >> going for a walk. taking a hike, going for a swim. >> her healthy lifestyle and good looks were hard to miss. >> is seemed guys always really liked her. she was not trying to attacked -- a track attention but she was someone people noticed her. >> she was very pretty. >> super pretty and she has those long legs. >> it was a complete package about diana. so smart, gorgeous. sweet, caring. >> diana went to work in the tech industry and ramped up her fitness routine. >> she competed in several triathlons and was a personal fitness coach. >> eventually, single and focus, she met someone who also loved bike riding and soaking up the outdoors. a software engineer named greg. >> he was gracious and very sweet. very much like her. >> after two years of dating, diana and greg tied the knot in august 2007. >> they seemed like the right fit and she seemed happy. >> they were eager to start a family. but that didn't come easy for her? diana suffered multiple miscarriages and then had a difficult high risk pregnancy which made september 2012 all the more special when she gave birth to a healthy baby boy. that must've been an incredible day for her to know the baby was born. at last, diana had a happy family. that would not last long. by the time the sun turned two, the marriage was falling apart. diana kicked greg out of the house and got a restraining order against him. in court documents, diana alleged that greg said he wished her dead. that he sexually molested her in her sleep, and she suspected he also molested their son. greg denied all of the allegations and fired back said diana had verbally and physically berated, attacked, and belittled him over the last several years. things were getting ugly. >> things were getting ugly. >> greg filed for divorce and the couple thought bitterly over custody of their son. at first, greg was only allowed supervised visits. after numerous evaluations by therapists and law enforcement, courts found no evidence of abuse and ultimately awarded greg 50/50 custody with diana. diana was scared for herself and her son. a fear that ultimately led her here, shooting range. >> i was surprised when she was taking lessons, this is more serious than i thought. she is concerned about her safety in a really, really real way. >> at the range it seemed diana met the man she was looking for. a former marine skilled in self- defense. someone you might know too from dateline. >> coming up. >> i've always been very protective person. >> we first met him when he helped rescue a woman from danger. >> he sounds like he was looking up for you a little bit. >> he helped me so much. >> when he met diana, something changed. >> she would text him at all different times. i did not like that. that. say hello to your fairy godmother alice, and long-lasting gain scent beads. part of the irresistible scent collection from gain. 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( announcer) you can quit. for free help, call 1-800-quit-now you are bountiful. your skeleton can support two times your weight. it's in your nature to stand strong. supplement your bones with high-absorption magnesium. nature's bounty. it's in your nature. dave's company just scored the comcast business 5-year price lock guarantee. high five! high five... -i'm on a call. it's 5 years of reliable, gig speed internet... five years of advanced security... five years of a great rate that won't change. yep, dave's feeling it. yes. but it's only for a limited time. five years? -five years. introducing the comcast business 5-year price lock guarantee. powering 5 years of savings. powering possibilities. - [narrator] life with ear ringing sounded like a constant train whistle i couldn't escape. then i started taking lipo flavonoid. with 60 years of clinical experience, it's the number one doctor recommended brand for ear ringing. and now i'm finally free. take back control with lipo flavonoid. one diana lovejoy decided to take shooting lessons for self-defense, she went to a range called iron sites and that's where she met a man with the expertise and attitude she needed. >> i hate bullies. >> weldon mcdavid was passionate about protecting other people. >> i used to protect my friends on the way home from school. we had a bully who tried and tried to start fights with us. i found out that nicely applied arm lock would get the bully to kiss the street and we didn't have to run from him anymore. >> he enlisted in the marine corps after leaving the service, he worked as a firearms instructor. we met him in 2013 when we covered the story of another woman he met at the shooting range. >> the customer walked in and i could tell something was wrong with her. i couldn't tell what, but i could read she was under stress. >> her name was crystal harris. >> he was like can i help you? i said i need to buy a gun. it's not just for putting it away. my life is in danger. it's from my husband. he was like, whoa. >> crystal a mother two sons said her husband was violent and abusive. she said she wanted to buy a gun for protection. >> at that point, i asked are you prepared to kill him? because that's a very real possibility. his life, your son's life, or your life, you have to make that decision. after a few moments she said, yes, if i have to. >> weldon to crystal under his wing and taught her to defend herself even in stressful situations. sounds like he was looking out for you a little bit? >> yeah, somebody in the business of saving lives. you know, a warrior and hero and that mentality, yeah, he wanted to help me. >> at home crystal helped herself. used a mini cassette recorder to gather evidence against her husband. >> oh, god. stop. please, please stop. >> when i christer captured something horrible and said it was audio of her husband. >> you're choking me. >> she walked in and was visibly shaken. i knew something had happened. >> crystal played a bit of the tape for weldon. >> i've always been a protective person. if you are friend or family, i will do anything for you. i really wanted to go and kill him. >> crystal later called police and had her husband arrested. when he made bail, she called weldon who came to her house to find the safest place to hide. >> checked out the house top to bottom. told her defensible spaces. >> crystal never needed to use her gun. her husband was convicted of a forcible sex crime and found -- spent five years behind bars but she was grateful for the sense of empowerment and protection that weldon mcdavid gave her. >> he helped me so much. >> it's an unlikely friendship. >> if i was worried about something or needed him, could call him. >> crystal embarked on a new life without her husband and weldon moved in too. a few years after befriending crystal, weldon found romance when he meant a woman called leah. >> i had decided to learn how to shoot and buy a firearm and learn how to use it. i was tired of feeling vulnerable as a woman. scared of noises at night. >> she said weldon didn't make a huge impression when he rang up her purchases but soon she realized. >> he was interested and i was not, at first. he won me over. >> how did he do that? >> he is witty and has good intelligence and humor. really engaging personality. >> weldon told her about his work with crystal harris. >> it was consistent that he had helped people feel confident and safe. >> just like crystal, leah felt empowered around weldon. >> he is strong and i enjoyed his strength and i felt safe around him. >> leah became missis mcdavid. listened two years later, she gave birth to their son. somewhere in there weldon told her about another woman he was helping at the range. a woman named diana lovejoy. >> he told me about her husband and she was afraid of him and they were going through a divorce. >> it seemed weldon had assumed the role of protector. this time in diana's life but leah but something didn't seem quite right. >> she would text him at different times about things. i did not like that. i didn't think it was professional. we disagreed about him communicating with her, and i think he saw the need of somebody both herself and more so her child who could not protect himself, and felt like he needed to help. >> something weldon had done all his life. leah could understand that . what she could not understand was what came next. >> this is 911. >> friend has just been shot. >> with got the paramedics. were getting the paramedics on route. >> a sniper waiting in the dark, but who was the target? 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[ speaking minionese ] [ laughter ] good luck with that. hello, this is 911. >> on a moonless night, september 1, 2016. >> my friend has just been shot. >> the man on the line describes a scene that doesn't happen in this affluent community. multiple gunshots fired. appearance sniper on the loose. >> he was lying down like in a sniper position. >> i'm at home and sleeping. >> carlsbad detective sergeant darby is on call that night. >> we are calling every detective that's available to come in. >> she learned the 911 caller was a man named jason and he was calling about his coworker. diana lovejoy's husband, greg mulvihill. >> he said his friend greg mulvihill had been shot and they needed assistance immediately. >> ernst learn when the first officer got to the syncope found greg and his car, bleeding from a gunshot wound. >> he was shot in the left side of his chest and the bullet went essentially in through the front and out the back. >> while greg was rushed to the hospital, a s.w.a.t. team come the hillside where he had been shot. did they find the shooter? >> no. vanished. >> sergeant ernst heard a detail that was curious. when the 911 call about the shooting came in, the situation immediately ring a bell with the dispatchers. >> greg mulvihill called the dispatchers earlier in the evening to ask advice. he received a phone call from an when a person stating that person was a private investigator and had some information. >> greg said the mysterious caller was a man with a deep voice who claimed to have documents that greg would want to see. he got the impression it was evidence that could be used against him in his custody battle against diana. the man said he would leave a package for greg to pick up. greg asked the dispatcher whether he should go. what was the response? >> probably not a good idea but it was up to him. >> and he went. this was the meeting spot. isolated dirt road near a power pole. greg asked his boss and neighbor jason to join him on this bizarre mission. jason told police around 11:00 p.m., they pulled up to the intersection of the dirt road. the sergeant and the detective took us there. >> the package was supposed to be taped along the power pole. >> greg carried a bicycle light and gave his friend a child's baseball bat, just in case. they walked along the path and looked for the package but could not find it. greg scanned the area with a slight but then noticed in the brush. >> he sees it's a person laying on the ground holding a rifle. >> that's terrifying. the man appeared to be wearing camouflage. greg or jason yelled gun or maybe run. >> they turned into back towards the car. that is when mulvihill was shot. as they are running back, they are hearing multiple rounds whizzing past their head. >> they got in the car and took up but then greg realized how badly he was injured. he pulled over and jason called 911. greg mulvihill was being hunted but he did not know the trap he was walking into. >> correct. nor who was sending him. >> greg survived his injuries. >> he was in the dark and didn't have any idea who would do this for anybody he could think of that would do this. >> greg did say he was nearing the end of it custody dispute with his wife but quickly dismissed the idea that she could've played any role in what happened. >> she's not the type of person. she couldn't be involved in any way. >> police paid a visit to diana, and she had no idea who shot greg. >> there's nothing in his history that would've led us to believe he was involved in criminal activity or any of his acquaintances would've done him harm based on activities he was involved in. >> didn't have secrets from his job? high-level job with computers? >> he brought his bus with him to the crime. >> the sergeant had one lead to follow. >> we need to get to the phone number that was used to call him to lure him to this area. >> when the number was traced. >> it was a burner phone. there won't be subscriber information. >> they were able to track the purchase of the phone to this best buy about four miles from the crime scene. >> they had the video surveillance of the purchase. >> best buy email the sergeant still photos from the surveillance camera. >> i called in scott and other detectives to be ready for who this mystery person was going to be buying this tracfone. >> who was it? >> coming up. a would-be killer caught on camera. >> is this a smoking gun? king this is a hot flash. but this is a not flash. for moderate to severe vasomotor symptoms due to menopause... ...veozah is the first and only prescription treatment that directly blocks a source of hot flashes and night sweats. with 100% hormone-free veozah... ...you can have fewer hot flashes... ...and more not flashes. veozah reduces the number and severity of hot flashes day and night. don't use veozah if you have cirrhosis, severe kidney problems, kidney failure, or take cyp1a2 inhibitors. increased liver blood test values may occur. your doctor will check them before and during treatment. most common side effects include stomach pain, diarrhea, difficulty sleeping, and back pain. ask your doctor about hormone-free veozah... ...and enjoy more not flashes. you could save on veozah. visit saveonveozah.com to learn more. (michael) copd is harder on the folks around you, i think. my wife smoked, and she quit. because she needs to be here for to take care of me. (announcer) the people you love are worth quitting for. you can quit. for free help, call 1-800-quit-now. [sneezes] can a can of lysol take care of my snotty sofa? can-do mildewy tiles? can-do - these? - yup, it's the can-do can. nothing kills more germs on more surfaces than lysol disinfectant spray. - [narrator] life with ear ringing sounded like a constant train whistle i couldn't escape. then i started taking lipo flavonoid. with 60 years of clinical experience, it's the number one doctor recommended brand for ear ringing. and now i'm finally free. take back control with lipo flavonoid. - [narrator] life with ear ringing sounded like a constant train whistle i couldn't escape. then i started taking lipo flavonoid. with 60 years of clinical experience, it's the number one doctor recommended brand for ear ringing. and now i'm finally free. take back control with lipo flavonoid. i'm richard lui and these are the news headlines. much of the country expected to start baking under the heat wave that began last week. record temperatures possible in states with dangerous heat. police in ohio seeking a suspect after a mass shooting in columbus early sunday. it left 10 injured. victims range from 16 to 27 and nine are listed as stable while one is critically wounded. welcome back to dateline. i'm craig melvin. investigators believed greg mulvihill was being hunted. he received a phone call from a stranger who offered to turn over potentially damaging information, but instead led greg into an ambush. scouring the scene, police enough in the gun man but they did track down a promising clue . one that was about to leave detectives to a startling to discovery. my friend has been shot. >> greg mulvihill had been shot and barely survived. someone had lured him to the scene of the crime of the call from a burner phone. now, police gathered around a