that's all for this edition of "dateline." i'm natalie morales. thanks for watching. i think i was just in shock to find out that she's gone. and the cause is a gunshot wound. you just wonder, how could this 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 wife dying on the floor. >> she wasn't talking at all. >> i'm asking him, like, conrad, what happened here? >> i was utterly confused. >> so many different stories about what might have happened.

>> he said many things that night. >> maybe someone could have shot something at the house. >> at one point he said that 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 that commit suicide naked. >> conrad's stories were not adding up. >> but something else wasn't adding up either. a key piece of evidence. >> we went to the house, and we walked in and we think, a-ha! >> would a mistaken 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's going to break, and when it does, the truth's going to be known.

>> i'm lester holt, and this is "dateline." here's josh mankiewicz with "as night fell." >> reporter: they seem so incongruous, the soaring majesty of utah's wasatch mountains, and here's josh mankiewicz with "as night fell." >> reporter: they seem so incongruous, 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 will tell you, both the evidence and the jury have their own stories to tell. and the answer's 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 the baby, she was favored. everybody loved her. she could do no wrong. >> reporter: autumn was one of heidy's four sisters. >> she was just special. you know, she'd walk into the room and she's ready for that good time. >> reporter: 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 an appropriate name. >> reporter: heidy's mom, janet. >> the family would get together and we were kind of loud and boisterous sometimes and she kind of got embarrassed easily. she'd hide her face. >> reporter: as heidy got older, 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. >> reporter: 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 co-workers. >> we worked with hazardous chemicals and gasses. crazy things that you wouldn't expect a couple of girls to want to do. >> reporter: heidy seemed 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. >> reporter: to sandi, heidy became more than a co-worker. >> i considered her my best friend. she's a person that you knew into never stab you in the back. she's a person that you knew would always have your back. >> reporter: 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. >> reporter: what did you think? >> i thought she was cute, and i noticed her hard hat, and they have a little personality or

stickers, you know. and hers said, it's all about me. deal with it. i was kind of thinking this girl's kind of a feisty girl. >> i want to try it again. >> reporter: soon conrad asked heidy out on a date. >> i'm not that type usually. i don't get superserious right off the bat, but it was almost like we were inseparable after that. >> reporter: that first night? >> yeah, yeah. >> reporter: this tough girl even shared conrad's interest in guns. >> we would go to the range out of town and shooting in the hills. >> reporter: heidy knew how to handle a handgun? >> yes. >> reporter: one year into their courtship, conrad decided to pop the question. in true utah form, he chose a mountain on which to do it. did she have any idea it was coming? >> no. so i got on one knee, and i asked her and i started bawling. and she just said yes right off the bat. >> reporter: conrad's sister colette couldn't believe it when her brother first introduced heidy to the family. >> i was actually really sort of surprised when i first met her, like how did he hand that girl? they just seemed to be such a great match.

>> reporter: you saw love and chemistry there? >> oh, it was almost awkward. they were definitely an enviable couple. >> reporter: another year later came the wedding. >> it was amazing. we went up on a lift, a chair lift, then all of the guests left 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. >> reporter: 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 trumans were married. tell me about that day. >> that day was like, just like any other day. >> reporter: as night fell, heidy decided to take a bath. conrad said he went to the kitchen to get something to eat. as he fixed 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 two strings or you can pull one and confetti and stuff comes out. >> reporter: that's when conrad said he turned and saw heidy standing there in the hallway naked. >> she wasn't talking. she wasn't talking at all. she was coughing, she was heaving. >> reporter: and she was bleeding? >> she was bleeding out of her mouth and her nose. i needed to call 911 immediately. >> 911, what city is your emergency? >> utah. >> reporter: an unimaginably shocking scene. heidy on the kitchen floor in a pool of her own blood. conrad on 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. >> reporter: as you will learn, truer words may never have been spoken.

>> what had happened in that house? when we return -- >> i'm asking him, conrad, what's going on? he said, i don't know what happened. everything was just different answers and different theories, different little things. >> a search for answers and a race to save heidy. >> this is not happening. this is really not happening. wo. they want to get rid of their pain as quickly as possible. why would somebody want to suffer if there is options that they don't need to. i think dentists will want to recommend sensodyne rapid relief. sensodyne rapid relief builds a layer fast on the tooth's surface over those sensitive areas, which means patients are going to get fast relief from their sensitivity. sensodyne rapid relief is clinically proven to work in 3 days. i think dentists will want to recommend this product because it's going to help their patients and that's what we are trying to do is help patients. w...that keep us active every day.... like you, your cells get hungry. feed them... ...with centrum® multigummies.

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♪ something was wrong at the 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? >> reporter: the 911 call came into the orem, utah, police department at about 11:00 p.m. that september night back in 2012. >> we got a call of a gunshot wound or some sort of injury. >> reporter: sergeant bill crook went to the truman home. >> so we all kind of rushed to our cars and headed that direction with lights and sirens. >> reporter: 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. >> reporter: 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.

>> reporter: by then, conrad said he realized heidy had been shot in the head. when you went to heidy, did you see a gun? >> no. >> reporter: 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 wasn't very lou and, you know, maybe someone could have shot something at the house. >> reporter: it seemed farfetched but he said neighborhood vandals had recently been shooting the back of his house with paint balls. >> i was utterly confused. >> reporter: within minutes, sergeant crook arrived. conrad by now had moved to the doorway of his home to wave crook down. >> he had blood on his hands and he was screaming and shrieking. >> reporter: conrad led the sergeant through the front door, up the stairs, and then into a scene straight from a horror movie. >> i could see heidy laying there. she was naked, blood everywhere, just right at the top of the stairs, just this horrific scene. >> reporter: what's conrad

doing? >> he's screaming and he's yelling. >> reporter: and, as these police photos make clear, covered in blood. >> i'm asking him, like, conrad, what's going on? what happened here? he said, she was in the bathroom, you know, and just, i don't know what happened. everything was just different answers and different theories, different little things. >> reporter: right away crook went to check one of those theories, a stray bullet perhaps coming through the bathroom window. >> the window was closed but there's no bullet hole. >> reporter: nothing to indicate that anybody fired a shot. >> that's correct. >> reporter: crook 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. >> reporter: was this an accident? an attempted suicide? or something far more sinister? at least for now, those answers would have to wait. heidy was clinging to life. >> my focus at that time was, honestly, was to help heidy. >> reporter: 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. >> reporter: about an hour after conrad arrived, hospital staff delivered the devastating news. heidy wagner truman could not be saved. >> it was pain, it was misery. it was why, how? >> reporter: 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 and that pain, that agony of knowing that your daughter, for whatever reason, is dead. is gone. >> reporter: the officers wouldn't give 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 as it is that we lost heidy, we're going to have to be supporting conrad because he must be overwhelmed with grief. >> reporter: conrad's sister colette was thinking the same thing as she raced to the hospital. what kind of condition was your brother in then? >> he was just a total wreck, just absolutely hysterical. didn't know how it could have happened. >> reporter: no one did. but back at the truman home, sergeant crook had started analyzing the evidence and was already developing a theory. >> i thought, oh, man, there's something going on here. >> reporter: you got a feeling? >> i got a feeling, yes. it wasn't just me. everybody was kind of looking around like there's something wrong here. we need a detective. coming up -- was it an accident? suicide? >> we don't see a lot of women who commit suicide naked. >> or something else? >> i felt like they thought i

did something.

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. >> reporter: soon after he arrived at the scene, sergeant bill crook did begin to have his suspicions. >> we're telling him, conrad, back off. the paramedics are here. back off. and he wouldn't. >> reporter: he was what, moving around? >> yes. >> reporter: keeping paramedics from being at the body? >> yes, sir. >> reporter: there were other scenarios that needed to be explored, like accident and suicide. that's where detective tom wallace came in. >> there had been a number of theories. we obviously are going to exhaust them. that's going to happen. >> reporter: the medical examiner didn't 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 hard to believe.

thanks to conrad, heidy had firearms experience. can you think of any way it could have been an accident? >> no. heidy wouldn't have been so careless. >> reporter: so what about suicide? >> she's completely naked. we don't see a lot of women that commit suicide naked. that's not common. >> reporter: did you find anybody that heidy had spoken to about suicide or about being depressed? >> no. >> reporter: 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, heidy was against that. she had a friend who committed suicide, and she thought it was selfish and, in her words, dumb. >> reporter: heidy ever tell you she was depressed? >> no. >> reporter: ever act depressed? >> no. she was probably one of my happiest, most upbeat kids. >> reporter: 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. >> reporter: crook found those threats so alarming, he took out his phone to record them. >> you're gonna [ bleep ] die and everyone in your life is going to die if she dies. >> it could be the way this guy reacts to trauma, but i'm telling you it was a red flag at the time. >> reporter: also a red flag conrad was drunk. he admitted he and heidy had been drinking earlier that night. >> i could see in his eyes, the redness. >> reporter: 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 ask 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. >> reporter: as for the location of the gun itself, that, too,

was suspicious. that gun's how far from heidy? >> oh, i would say eight feet, ten feet maybe. it's far enough away that it wasn't a normal if she shoots herself and falls to the ground type of thing. >> reporter: next morning they ask conrad to come to the station for more questioning. >> they can say whatever they want. but i did not hurt my wife. and i know that. bottom of my heart, i did not hurt my wife. >> reporter: heidy's family thought otherwise. after finally learning from police the details of how heidy died. >> the minute i heard how she died, i knew he did it. >> sounds like he had a temper, and he was very intoxicated, and he did something that perhaps he didn't plan? i just knew he did it. >> reporter: detective wallace next pored 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 and catches her or she falls down. >> reporter: 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's at the top of the staircase. it doesn't add up that she would have traveled that distance he said she had gone then fallen in that location. >> reporter: it was hard for wallace to believe that heidy could have traveled from the bathroom to the stairs after sustaining such a head wound. >> she would have fallen immediately to the ground. >> reporter: wallace shared his findings with assistant district attorney craig johnson. johnson agreed. everything pointed to conrad. why would conrad truman want to kill his wife?

>> under the circumstances, i'd say the motive was just based on this heat of passion argument that they were having. alcohol, a fight and guns, that's where we got murder. >> reporter: at the same time johnson was still reluctant to press charges. remember, the state's 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 in courts with juries, a medical examiner carries a lot of weight. >> reporter: so johnson and wallace showed the m.e. a 96-page power point presentation of all their evidence including those measurements, hoping something would sway him. the presentation worked. the medical examiner changed his ruling to homicide. it sounds like one of the things that got the medical examiner to move from inconclusive to homicide was the measurements of the crime scene suggested that her body was too far from where mr. truman said she'd been shot. >> exactly. >> reporter: so after a

ten-month investigation, the orem p.d. and the d.a.'s office arrested truman and charged him with murder. >> my mom called me and i fell to the ground crying and so happy that he was finally behind bars. >> reporter: going into trial, what did you think? >> i thought we had a strong circumstantial case. >> reporter: 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. >> reporter: and as far as you knew, that was it? >> that was it. >> reporter: did you think that was it? >> i did. >> reporter: but if you think that was it, well then you haven't been watching enough "dateline." coming up -- heidy's heartbreak.

>> she did not know her dad, and she had always wanted that. that really bothered her. >> and conrad truman's hope. >> this is going to work out. it has to because i didn't do this. i knew my daughter could be at risk of certain cancers later in life. from an infection, human papillomavirus i knew that hpv could lead to certain cancers. i knew her risk for hpv increases as she gets older. i knew there was a vaccine available that could help protect her before she could be exposed to hpv. i knew. so i talked to my child's doctor. now that you know that hpv can lead to certain cancers, don't wait. talk to your child's doctor today. you should know the location of a decent bathroom.ation, my gut says, take new benefiber healthy balance. this daily supplement helps maintain digestive health naturally while relieving occasional constipation and abdominal discomfort. new benefiber healthy balance

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just more than two years after his wife heidy's death, conrad truman stood convicted of her murder. he was looking down the barrel of a life sentence when he returned to a utah courtroom to learn his punishment. this is the moment where some convicted killers ask for mercy because of their difficult lives or tell the court they've been misunderstood. and sometimes, of course, they don't speak at all. but not conrad truman. >> listen to me, please. i can't say sorry for something i did not do. i understood speaking out would make it way worse, that i was like -- i don't know. i was like to hell with this. i need to speak my mind. i didn't kill my wife. there's just no way. if there was proof and i didn't. that's why there is no proof. you know, this is just a big injustice. >> reporter: the judge had heard that before. the sentence he imposed?

16 years to life. crushing for conrad and his family sitting behind him including sister colette. >> you want to believe that things turn out the way that they're supposed to. and that's just not always the case. >> reporter: in prison conrad did what many do -- he retraced the steps that led him there. and he thought a lot about the night heidy died. as conrad saw it, the police rush to judgment began precisely when officers first rushed through his front door. >> this guy's drinking, there's firearms in the house. so he must have shot her. >> reporter: why couldn't it be exactly that simple? this wouldn't be the first time that mixing alcohol, an argument and a handgun led straight to a prison sentence. conrad told us what he told police. it isn't that simple. sure, he and heidy had been drinking and, yes, they had been arguing, but he said neither was

an explanation for what happened. >> i could have upset her with some of the things i've said or the way i acted with not -- being attentive, you know, to her. i know i do that sometimes when i drink. i don't pay a lot of attention. you know? >> reporter: this still doesn't seem like grounds for a gigantic fight. >> no. it got to the point where i think she was -- i upset her. i was really -- i just know she went to go take a bath. >> reporter: which is what she did when she was a little irritated? >> yes. >> reporter: conrad also shared with us how he picked the bathroom lock, not, he said, to confront heidy, but just to apologize. >> she just said get out. i was like, okay. so i just let her be. >> reporter: as for conrad's behavior after police arrived at his door, he said he had good reason for acting that way. >> i was trying to save my wife. i don't know. does that make sense? i just wanted her to live. >> reporter: i get how frantic

you must have been. i'm not sure i understand the threatening part of that. and i think that's one of the things that ended up getting you in trouble. >> could be. and i was like, do i have to -- how do i explain this to you guys? get her help. and when you can't explain that to someone, i just started -- i started making threats. >> reporter: well, if all that's true, then why and how did heidy wind up with a bullet in her head? i think police found it hard to believe that you could be right there with her in a very small area -- >> mm-hmm. >> reporter: -- and she's shot, and you don't know what happened. >> yeah. maybe in their heads. in mine, i was confused. >> reporter: could this be an accident? >> what i say to that is i didn't see. i don't know what happened. >> reporter: that's how he felt just hours after the shooting, but as the months passed, conrad came to the conclusion heidy may have taken her own life. his wife, he said, wasn't as tough as she appeared.

was she a sad person? was she a depressed person? >> when she drank a little bit, you could see it come out. it wasn't every time. but it did. >> reporter: heidy's friend sandi sanchez also saw another side to heidy. >> that strong, funny, you know, person also had some things inside that were very painful. >> reporter: according to sandi, those things had to do with heidy's upbringing. most significantly, heidy grew up not knowing the identity of her father. >> that really bothered her. you know, she did not know her dad. and she had always wanted that. >> it bugged her tremendously. >> reporter: enough to take her own life? had she ever attempted suicide before? >> never to my knowledge, no. >> reporter: she never talked about it. >> no. >> reporter: it's very hard to believe that what was going on in heidy's life at the time, what seemed like a pretty happy marriage to you, she's going to

spur of the moment decide to commit suicide like that? >> well, that's a tough question. it's like how do you really know when someone's going to do that, you know? >> reporter: as he lived his life behind bars, conrad continued to speculate. he also tried to stay hopeful. >> i was just like, this is going to work out. it has to because i didn't -- i didn't do this. >> reporter: conrad's family never gave up on him. so they scraped together the money to hire conrad some new attorneys. >> mark and annie looked into the case. to them it was immediately apparent that there were a lot of problems. >> reporter: mark moffat and ann taliaferro were those attorneys. one of the first things they did was visit the scene of the crime. >> we went to the house, and we walked in and we think, a-ha. >> within moments of being in that home, we knew immediately that there was a huge problem. >> reporter: not a problem for them.

more for the people who had put conrad truman away. coming up -- is an innocent man in jail for someone's mistake in math? >> i remember thinking, well, that's strange. that couldn't be right. while conrad truman sat in a we have to be able to repair the enamel on a daily basis. with pronamel repair toothpaste, more minerals enter deep into the enamel's surface. you have an opportunity to repair what's already been damaged-it's amazing. the way you triumph over adversity. and live your lives. that's why we redesigned humira. we wanted to make the experience better for you. now there's less pain immediately following injection. we've reduced the size of the needle and removed the citrate buffers. and it has the same effectiveness you

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while conrad truman sat in a utah state prison marking time, his sister colette searched endlessly for ways to get him out. was there a time when you or anybody else in your family thought maybe we don't know him as well as we thought we did? >> no. >> reporter: he couldn't have killed her? >> not possible. >> reporter: so much about conrad truman's trial bothered his sister colette. but one detail in particular kept gnawing at her. it had to do with the diagrams used by the state depicting the area where heidy's body was found. >> i remember thinking, well, that's strange. that's -- that couldn't be right. >> reporter: post-verdict, colette shared her concerns with conrad's new attorneys, mark moffat and ann taliaferro. they decided to visit the truman home to see for themselves if the state's diagrams were accurate. we later made that same trip

with moffat who showed us what they discovered. this is the area in question, and it's pretty small. >> it is. it's really small. we immediately started measuring, and we knew right away that there was a big problem with their diagrams and the measurements. >> reporter: the problem? all those measurements were off. >> instead of 139 inches, somebody took the figure 139 and interpreted it to be 13.9 feet. 33 inches became 3.3 feet. and on and on and on. >> reporter: according to moffat, those flawed measurements, which were used in court, made the house appear much bigger than it was. >> they used the theme of distance to argue that mr. truman was lying about where he said his wife was when he heard what turned out to be this fatal shot. >> reporter: at trial, the prosecution argued, to believe

conrad, you'd have to believe heidy shot herself in the bathroom and then walked 12 feet before falling to the floor. and, according to the medical examiner, that was impossible. he testified heidy's head wound was so severe that she could have at most walked a step or two. >> this issue of distance was this big issue. >> reporter: now for ann taliaferro, just seeing the house and how small it was was proof enough that the prosecution's argument didn't hold up. >> when you walk in the house, there's no way that there's even 12 feet there. >> reporter: what's more, according to the defense team, conrad never told the police heidy shot herself in the bathroom. instead he told them he had no idea where she was when he heard the shot. tell me your theory of what happened here. >> we believe that heidy truman shot herself in this very area, and we believe that she fell right in the area directly in front of me on the ground, and that's the very area where she

was found when law enforcement entered the home that night. >> reporter: which they also said was completely consistent with the m.e.'s testimony that heidy would have fallen after only a step or two. >> she would have gone to the ground immediately. >> reporter: your argument is she did fall down. >> exactly! >> reporter: and she fell right about here. >> yes. that's exactly what our argument is. >> reporter: according to moffat, this was not a simple mistake. is this just a case of a smalltown police department making incorrect measurements or adding up some figures wrong? >> i don't believe so. i believe that they willfully lied to secure a conviction against conrad truman. >> reporter: and for these attorneys, there were more issues with the state's case. one had to do with gunshot residue tests. the defense learned police swabbed both heidy and conrad's hands, but those swabs were never sent to the lab. >> when you have gunshot residue that was never tested, those things matter. >> reporter: the defense team decided to test those swabs themselves.

conrad's hands were negative for residue, but there was a question as to whether conrad had washed his hands before they were tested. so those results were meaningless. >> that's probably why they didn't test in first place. >> reporter: as for heidy's swabs, there was no residue on her left hand. but there was on her right hand. and significantly, heidy was right-handed. >> when you have gunshot residue in a location and in a quantity that is absolutely consistent with her firing a semiautomatic weapon, one of the possibilities is that she fired a gun. you can't discount that. >> reporter: the deeper moffat and taliaferro got into the case, the more it seemed to them heidy's fatal wound was self-inflicted. they believe the head wound, a contact wound, ruled out homicide. >> a contact gunshot wound to the right temple are the most common site of self-inflicted gunshot wound that there were. >> reporter: moffat and

taliaferro decided to take their findings to the m.e. hoping to sway his ruling on the manner of death once again just as police did prior to conrad's arrest. >> we gave him a bunch of information, then he, on his own, with his investigator, went to the home to look at it. >> reporter: and the result was just what they'd asked for. heidy truman's manner of death, once undetermined, then a homicide, was now officially, once again, undetermined. it was manna from forensic heaven. how often do medical examiner's change their findings and then change them back? >> i've never had a case where this has happened ever. >> reporter: it took another year, but conrad truman's conviction was overturned, and he was granted a new trial. >> i never even thought that was even a possibility for the medical examiner to change. i never would have thought that. >> reporter: is there part of

the things about i can't get my hopes up? >> yeah, that's exactly how i felt. >> i was beyond happy. we were just absolutely over the moon. >> reporter: for heidy's family, it was just the opposite. >> we couldn't believe it. >> reporter: you thought this was over? >> we thought it was over. we thought this was settled. >> that was a hard, hard moment. we hated it. we just thought, so what are they going to come up with this time? >> reporter: and we know that's what you're thinking, too. coming up -- a new trial, a new jury, a different verdict? >> there was enough "there" there beyond reasonable doubt. >> why would things work out if it didn't work out the first time? ty of non-drowsy children's claritin allergy relief. the #1 pediatrician recommended non-drowsy brand. because to a kid a grassy hill is irresistible. children's claritin. feel the clarity and live claritin clear.

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conrad truman had been convicted of murder, sentenced to life and had already served more than three years. now, the revelation of those flawed police measurements had led to conrad truman's new trial. that stunned everyone in the utah county d.a.'s office. especially the man responsible for conrad's conviction. prosecutor craig johnson. >> this is something that really took us by surprise. >> reporter: the defense says you had to have known. >> well, that's their take, and they're doing their job to zealously represent their client, but i can tell you categorically that that's not correct. >> reporter: just as stunned was the man whose team took the measurements, lead detective tom

wallace. what went wrong? how'd that happen? >> in the process of transposing numbers from actual measurements at the scene to the crime scene program, numbers were just transposed wrong. >> reporter: wallace admits the error but says it was minor, that conrad truman did not deserve a new trial. >> it's not that significant as they made it out to be. >> reporter: did those incorrectly entered measurements change your opinion of conrad truman's guilt? should they change anyone's opinion? >> they didn't change my opinion. >> reporter: nor did it change the opinion of the deputy district attorney, tim taylor, who decided to take on the task himself of prosecuting conrad once again. >> i think craig had been into the case for a long time, so i wanted fresh eyes. so i went through all the evidence. and even with the medical examiner changing his opinion, i still felt that there was enough to go forward. but we knew going into it, it was going to be tough. >> reporter: at trial the prosecution's case was familiar.

starting with the officers who testified about conrad's rambling often incoherent description of what had happened that night. >> the core of our case were his inconsistent statements. >> the story was hard to follow. it was jumping around all over. it wasn't making sense to me. so it was hard to follow. >> reporter: those officers also told the jury about conrad's threats. >> he was telling us that we were going too slow and we needed to hurry up or he was going to kill us. >> i'll [ bleep ] kill you if you don't save her life. >> if you are making these violent threats to people who are there trying to help your wife, how are you treating your wife when it's only you and her alone? >> reporter: taylor then tackled the theory of suicide by calling witnesses to testify heidy was not suicidal. >> in your experience as heidy's mother, was she a sad or depressed person? >> no. i didn't see her that way. >> reporter: did heidy's not

knowing her father or not knowing who he was, did that make her depressed or sad? >> no, no. >> reporter: the prosecutor pointed out, conrad's story evolved over time. immediately following the shooting on the way to the hospital. conrad insisted hide wee never commit suicide. >> i think something shot her or something. because she would never shoot herself. she'd never shoot herself. >> reporter: taylor argued it was only later after suspicion against conrad had mounted that he changed his tune. as for the gunshot residue on heidy's right hand, taylor called an expert to say it proved nothing. >> nobody can identify a shooter based on the results of this test. that is a major limitation of this test. >> reporter: defense attorney mark moffat answered by telling the jury that, before being allowed to wash his hands that night, conrad had pleaded with police to confirm he had no residue on them. >> he's telling them, test my hands.

test my hands. i didn't shoot a gun. >> reporter: did you wash your hands before saying that to police? >> no, i absolutely not. i never washed my hands until they said, go wash your hands. >> reporter: conrad's attorneys were working hard to establish reasonable doubt, and the state medical examiner's shifting opinion on heidy's manner of death only helped them. that's your case right there. >> you would think. >> reporter: i mean, if he has reasonable doubt, hard to argue a jury shouldn't. >> exactly. >> reporter: the medical examiner told the jury that in the final analysis, he didn't know the manner of heidy truman's death. >> i finalized the autopsy report with the cause of death as gunshot wound and the manner of death as could not be determined. >> reporter: the m.e. also testified how, in his experience, a contact wouldn't like heidy's is rare in homicide cases. >> with the contact gunshot wound, it would be consistent with a wound that's self-inflicted. >> reporter: after 15 days of testimony, the jury began

deliberations. so you felt pretty good leading up to verdict? >> yes. there was enough "there" there beyond a reasonable doubt. >> reporter: conrad was having a much harder time. >> it was really difficult. you know? because why would things work out if they didn't work out the first time? you know what i mean? >> reporter: eight hours later, the verdict. hold up your hands. you're not wearing handcuffs. >> no cuffs. >> reporter: you're not in custody. >> i'm free. >> reporter: that's right. this time conrad truman got the verdict he wanted. not guilty. >> i just kept saying did they say not? >> he grabbed my arm. are you sure? >> reporter: in the courtroom, conrad's family shared tears of joy. >> i was giggling and crying at the same time. it was weird. >> reporter: on the other side of the courtroom aisle were tears of a different kind. >> i felt my heart sink and i just was in shock. >> reporter: you fainted? >> i did.

i couldn't believe there was a situation where that long shot happened, where he would be freed. >> reporter: juror brian christenson said he and his fellow jurors had no choice but to set conrad free. >> i believe that we all pretty much felt that he probably did it. >> reporter: but you voted to acquit. >> we voted to acquit. >> reporter: because you had reasonable doubt? >> we had reasonable doubt. >> reporter: whether you believe mr. truman is innocent or not, those measurements either put an innocent man in prison or let a guilty man go free. >> well, so you're right. but my opinion hasn't changed. do i think he got away with murder? yeah, i do. >> reporter: what's it like to have your work called into question in a way that frees the guy you helped to convict? >> it's that a measurement that's inconsequential actually ended up freeing him. >> reporter: what's life been

like for your family since then? >> we're trying to put the pieces together. >> reporter: for heidy's family, that is easier said than done. >> i miss the things that we had together. i miss the simple conversations. i miss her sassiness. i miss her wonderful personality. she lives on forever in our hearts. >> reporter: conrad is left looking both backward and forward. >> i mean, i'd do anything to take another day, another walk with her. i loved her. and i do love her still. >> reporter: you got a lot of life left, a lot. how are you going to live it? >> to the best of my abilities. >> reporter: there are jurors who think he might have done it but i had reasonable doubt, i couldn't vote to convict. >> well, god bless them. there's a lot of people who do believe in me.

>> reporter: he's made his own peace with a simple truth -- the very thing that freed him, reasonable doubt, could also shadow conrad truman for the rest of his life. that's all for this edition of "dateline." i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline." you've got a wealthy family. it's something for everybody. there is a club of people consumed by trying to figure out what happened. i've never seen anything like it. >> reporter: almost everywhere robert durst goes, mystery follows. a missing wife. >> everything about this reeked of murder. >> reporter: a murdered best friend. a dead neighbor. >> it's hard to understand. >> reporter: now the stories you haven't heard as those who knew robert durst best speak out in an exclusive interview.