>> just that you're still in my heart and i'll never forget you. >> i just want to know, whenever i do die, i just want people i love to know that whenever i die, that i was happy. that's all for this edition of date line. i'm craig melvin. thank you for watching. i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline." i said, "what's wrong?" and she says, "debbie's dead." we all wanted to believe it was an accident, there's no possible way he could do this on purpose. >> reporter: a dark house.

a husband with a gun. a wife dead on the floor. >> make sure that she is still breathing. >> i don't think she is. damn it! >> reporter: there was no question who killed her. the mystery was, why? >> i hear the door. squeaking, and i hear the grumbling, and i hear the dog growling. >> how can you not tell that's your wife? >> it was dark. >> he just kept sayin' it was an accident. he said he didn't do anything wrong. >> reporter: others disagreed. >> we never for a second believed that he didn't know who that was standing in front of him. >> reporter: was it a tragic mistake? >> he was broken. >> reporter: or cold-blooded murder? >> these bits of emotion are only done in front of the detective. they're not done when he's alone. >> reporter: a room too dark to see? >> so let's shut the light off, okay. >> reporter: or a story too hard to believe? >> there was nothing accidental about what he did. >> reporter: a shot in the dark, and doubt in the light of day. >> she's the love of your life? >> yes, sir.

>> the person you know better than anybody else? >> yes sir. >> and you can't tell it's her when you pull that trigger? welcome to "dateline." theirs was a marriage of opposites. she, the hard charging businesswoman, he the easygoing contractor. somehow, debbie and lars made it work, or so it seemed, until a gunshot ripped through the night leaving debbie dead and a family racked with doubt. was her death a case of mistaken identity or the bloody end to a marriage gone bad? here is andrea canning with "the silhouette." >> reporter: what happened inside this house would destroy everything the woman who lived there had worked for. she finally had it all, the career, the dream home, the

marriage she'd waited so long for. >> there was a brightness in her eye. >> i trusted that she knew her heart. >> they were in love. there's no other way around it. >> reporter: her life now complete, fulfilled, safe. >> we never worried about her. >> reporter: but was it all an illusion? >> send an ambulance, please! >> reporter: what happened that morning, in the predawn hours, in the dark? >> right in the freaking chest! oh! >> reporter: the women at this san antonio racquet club say you can tell a lot about a person by the way they play tennis. >> i think tennis in general just really brings out your personality. >> tennis either brings out the best or the worst in you. >> reporter: as for who had the best character at their club, the answer comes as fast as a serena williams' serve, their

friend, debbie kelly. >> debbie for me, was kind of the whole package of a person. fair, fun, and a great leader. >> reporter: debbie, fiercely independent, driven. >> always wanted to be a career woman. >> reporter: she climbed the corporate ladder in healthcare. her mom and dad, jim and anne kelly marveled at her commitment. >> she spent many, many hours traveling and many hours working overtime. >> reporter: but debbie hadn't found as much success in her personal life. she got married in her 20s, but it didn't work out. now in her 40s, and dedicated to her career, there was little time to look for the right guy. >> reporter: was it hard to date? >> it was hard for her to date. >> reporter: so in 2008 debbie took a new job that allowed her to focus a little more on her personal life. that's when she got serious about her tennis game. >> she was a little bit of a tiger. >> reporter: that's how she met this bunch, bette paese, soeurette shook-kelly, and ellen mitchell. >> she was not a big person.

but all of her went up, and the hair would fly up, and she would smash that ball. >> reporter: what would she do when she would make that shot and -- and the opponent was not able to return it? >> turn around, get ready for the next point. >> reporter: so she was humble? >> very humble. >> extremely. >> reporter: the ladies clicked off the court too -- bonding over post-match drinks. >> she had a great laugh. she throws her head back and chuckles, and just her whole body laughs. she had a real silly, funny, quirky side. >> reporter: i've heard that she was very private. would she talk about dating and guys with you all? or -- >> not with me. huh-uh. >> she just wasn't one to talk about herself, period, but i was always tryin' to find her somebody. >> reporter: how did she receive bette the matchmaker? >> well, she'd always be like, "oh no." >> reporter: husband or not, debbie was ready to plant some permanent roots. she bought a house in a gated community and began to remodel it, on her own. she told her friend liz sevilla all about it. >> reporter: was she like an hgtv type of girl? >> yes. oh, my gosh. hey, i'm going to home depot. she's workin' on the sprinkler

system or she's deciding on materials for the floor. >> reporter: but the busy executive couldn't do everything herself, so in 2012, she hired a contractor, his name was lars itzo. but once work got underway, lars seemed in no rush to finish the job. >> she was getting very frustrated and she's just like, "i wish this person would finish." >> he'd stay late and work, and they'd talk. >> reporter: but lars' siblings ken and kristi, said he wasn't dragging things out for the money, he had an ulterior motive. >> he goes, yeah, she keeps flirting and talking and we're laughing and having a good time. >> reporter: lars liked debbie, and he thought it was mutual. >> and he goes, "can i ask her out?" and i went, yeah, why can't you. >> reporter: so began an unlikely courtship between debbie, the petite powerhouse and lars, the six foot two nordic he-man. >> they were cute. they were goofy. >> like teenagers. >> they were, that first love. >> reporter: debbie got a kick

out of lars' laid-back ways -- just a guy into old-school board games, restoring muscle cars, and drinking texas' favorite, home-grown soft drink, dr. pepper. >> about a case a day. i mean, he had a lot -- >> reporter: what? >> of dr. pepper. >> at least a 12-pack, i know. >> reporter: i've never heard of someone drinking that much dr. pepper. >> i thought it would kill him. really. doesn't drink a lot of alcohol at all, just dr. pepper. >> reporter: and when private debbie brought lars out to meet her friends, they knew it was serious. >> he arrived with her, hand-in-hand. >> reporter: sure, they noticed lars was a different sort of match for their friend. >> he's very quiet -- >> he's got the blond hair that would go with being named lars. >> he seemed like -- a surfer big man. >> reporter: but to debbie, he was the right man. >> i felt like she was really in love with him. >> i can understand her thinking, "you know, maybe it's time to try something just different. >> reporter: and pretty soon that something different was official. after a year of dating, debbie

and lars were engaged. >> reporter: so baby brother finally settled down. >> he did, and he was happy. never seen him that happy. >> reporter: they married soon after at this chapel in arkansas, near her parents' homes. >> reporter: how beautiful did she look on her wedding day? >> oh, she -- the main thing is she just looked so happy. that was really important to me. >> reporter: debbie and lars embraced the contented rhythms of married life, spending weekends with family. enjoying the outdoors and her dog cody, but after two years together things started to change. debbie got a coveted promotion, to vice president. >> that was going to entail more traveling and lot more working, too. >> reporter: big responsibilities, more pay, but less time at home, less time with lars.

october 9th, 2015, debbie, recently back from a business trip, went to bed early for a morning tennis game. debbie's beloved cody slept on the floor beside her. the shades were down. lars joined them a little past midnight. four hours passed, and then -- >> san antonio 911. >> uh, just -- had a gun shot. >> reporter: what had happened in that texas home? when we return -- >> i thought a heard a burglar in the house. >> reporter: danger in the night. and a confrontation in the dark. >> damn it! oh! baby! ♪ ♪ protect your pet with the #1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years.

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♪ >> reporter: 4:13 a.m. lars itzo called 911. >> i'm a male. she's a female. >> will you send an ambulance please! >> reporter: that female was debbie -- shot and gravely wounded. >> i want you to walk over to her and make sure that she is still breathing. >> oh, i don't think she is, damn it. ahh. ugh. >> reporter: the 911 operator guided lars through cpr. >> kneel beside her. >> ahh! >> stack your hands. >> god damn it! oh, baby!

ugh. oh, man! right in the freaking chest! oh! >> reporter: police raced up to the house, dashcams rolling. the audio kept recording as they entered the house. [ dog barking ] >> door creaking open and the dog is barking. >> help me! >> reporter: they found lars standing over debbie's body back by the bedroom. >> lars continues to cry. >> go ahead and back up please. >> reporter: as an officer tended to debbie. lars tried to explain how the shooting happened. >> i thought there was a burglar in my house. i thought there were multiple people in the house. >> okay. did you -- what did you hear? >> i heard voices when i was in bed. >> and where did you hear the voices at? >> up front. >> okay and after you heard the voices what happened? >> i got up. i thought my wife was in bed with me. >> ok. >> i got my shotgun. >> reporter: as emts took over, trying to save debby, lars went

with police down to the station. they urgently needed more details. where were the intruders? were they armed? what did lars know? what exactly did he do? sitting in the interview room, wrapped in cody's dog blanket, lars took them through what happened, step-by-step. he said he was awakened around 4:00 a.m. by strange noises in the house. >> i hear the front door or the door squeaking, and i hear the grumbling, and i hear the dog growling. >> reporter: he said he'd never heard cody growl before, so he was instantly on alert. >> did you think they were male voices or female voices or -- >> i believe they were male. >> lars says he moved towards the sound that he heard, with his shotgun in hand. he reached this tiny hallway where he says he saw a silhouette standing in front of him about three feet away. he says he made a split second decision to fire his gun, fearing for his life. all of this happening he says in the pitch black darkness. >> about how far away were you from them? >> me to you. >> reporter: but the person lars shot was not an intruder.

it was debbie. police quickly determined that the only shot fired in the house came from lars's gun. he said it was an accident -- a case of mistaken identity. >> everything happened so fast. >> reporter: nevertheless -- >> any kind of infidelities going on between you or with her anything like that? >> no sir. i trust her completely. completely. >> reporter: lars answered each of the investigators' questions. >> reporter: in return, he just wanted to know one thing -- >> nobody has told me anything about if she's alright. >> reporter: so after two hours of talking, they broke the news -- >> i don't know how to tell you this, but your wife didn't make it. okay?

she is deceased. >> dammit. >> reporter: just before 10:00 a.m., police let lars go. ken and kristi remember their younger brother that morning, overwhelmed with grief. >> he was completely hurt -- shattered, you know. he was broken. >> in those hours afterwards, what was he talking about? >> he really wasn't talking. >> he was just in shock. if he opened his mouth, he broke down. >> reporter: across town debbie's tennis friends were out on the court, waiting for her to start that early morning match. >> reporter: one of their husbands came out to tell them about debbie. >> he called me over and said that lars had shot her. >> what are you thinking when you hear that? >> out of the box for you. >> it was very surreal. i couldn't even comprehend how could someone shoot somebody?

it didn't even make any sense to me. >> reporter: in arkansas, jim and anne kelly learned the news from their son. >> that's just the worst news that a mother could ever hear. >> how does your brain process that information? >> i don't think you do. i couldn't process the shooting part, i guess. it was just that she was gone. and a part of me died the day she died. >> just kept saying, not debby, not debby, not deb. >> reporter: debbie's parents flew to san antonio, to spend time with lars, to support him in their shared grief. >> he could hardly talk. he seemed extremely remorseful. >> was he saying everything that you would wanna hear? like, i messed, i did it, i'm sorry? >> apologized profusely for it and said it was just an accident. it was dark. >> some people might be really angry but you didn't go down that road?

>> we did not go down that road. we supported him. >> reporter: but that support was about to be put to the test. >> coming up -- >> i know that she was frustrated. >> how strong was that marriage? how dark was that night? >> that's your wife. height, weight, shape. how can you not tell that's your wife? >> when "dateline" continues. before people invite something new into their homes, they want to know who you are. we're almond breeze. and we only use california-grown blue diamond almonds in our almondmilk. cared for by our family of almond growers. blue diamond almond breeze. the best almonds make the best almondmilk.

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cancel anytime, and your books are yours to keep forever. no matter where you go this summer make it better with audible. text summer17 to 500500 to start listening today. >> reporter: lars itzo admitted he fatally shot his wife debbie. but said it was a terrible accident. from the very beginning, he cooperated with police. answered every question, no lawyer present. then, about eight hours after that first conversation about

the shooting, lars headed back to the station and sat down for a polygraph test. >> he volunteered to go do it. he's like, i'll take a polygraph. >> 'cause he said he didn't do anything wrong. >> yeah. >> reporter: but the polygraph indicated lars was deceptive in some of his answers. his brother and sister said it was perfectly understandable. >> well, he's nervous. he's in shock, you know? >> he couldn't even get his name right, his birth date, where he was born. >> reporter: maybe so but his performance on the polygraph was enough for detectives to grill him relentlessly. >> how could you not see that was a woman?

>> it was dark, sir. >> reporter: no matter how dark it was, how scared he was, how could lars fail to recognize debby three feet away? >> that's your wife. height, weight, shape. how could you not tell that's your wife? >> it was dark. >> do you understand how lame that sounds, lars? >> it's the truth. >> you're 36 inches from a human being, and you can't tell it's your wife. i don't care if it's pitch dark. no room is completely dark. there's ambient light from every room. it may not be much but it's enough to tell the shape otherwise, you wouldn't have fired. you obviously saw something 'cause you fired the gun. >> i said i seen a shape. >> reporter: lars insisted he thought there were intruders in the house and he and debbie were in danger. >> i thought there was somebody else in the house going down the hallway the other direction. i thought there was one coming at me this way. that's what i thought. >> what made you think that had happened tonight? cause your dog growled? >> yes sir. he never growls. he barks. >> reporter: there was no witness or apparent evidence to contradict him. after an hour of questioning police once again let lars go. six days later, he said his final goodbye to debby, her parents by his side. >> how was lars at the funeral? >> very composed, very reserved. uh, he stood up with me. >> what did that say, that the family was supporting him?

>> it said a lot. it was great. >> reporter: debbie's friends weren't nearly as supportive. >> did you say anything to him? did he say anything to you? >> no. >> no, i didn't. >> i did not. >> reporter: they were furious at lars for doing something so stupid, so careless. everything he did bothered them. even his taste in flower arrangements that day. like the one that's pictured here. >> there was a wreath up at the front that was a huge flower heart, and in the middle of it, it was broken with these lines. so it was this broken heart. and it actually looked like a heartbeat, and it was in such poor taste. >> she was actually shot in the heart? >> well, it penetrated the lining of her heart, yes. >> reporter: as family and friends tried to sort out their feelings police reviewed the case, looking to see if this was a crime or not. since even an accident can warrant criminal charges. and, sure enough 11 days after lars fatally shot debbie, he was charged with manslaughter. >> anything you want to say?

>> reporter: prosecutors karl alexander and leo gonzalez caught the case. >> why did manslaughter fit? >> manslaughter is defined in the texas penal code as causing the death recklessly of an individual. >> essentially, that's what it boils down to. it was somehow somewhat of an accident. >> reporter: lars was released on bail. debbie's parents continued to support him. >> manslaughter is still, in our understanding, would be -- >> an accident. >> and so we go forward from there. >> reporter: but as the days without debbie stretched into weeks, something cooled in their relationship. >> he starts changing in term of my conversation, connections with him. and he's not so forth coming if i ask him something, he kinda holds back. >> reporter: lars' sister said his behavior could be explained. he had sunk into a deep

depression. >> he just kept sayin' he wanted debbie back, if he could get her back. it was an accident. he was sorry. >> reporter: investigators, as they worked through the case, looked into the couple's finances. debbie's assets totaled more than a million dollars when she died. her dad was named as the beneficiary on most of her investment accounts. so lars, it seemed, had little to gain by killing her. still, the whispers continued among debbie's friends. who told investigators there was another side to the marriage. >> i know that she was frustrated. >> reporter: even simple things

caused tension. liz sevilla volunteered that lars the contractor was slow to finish projects around the house. >> she did send me a picture of what lars did in the bathroom and the measurements were incorrect. and so it ended up making a hole. she goes, "i just want my bathroom fixed." >> she would express frustrations about lars sitting around on the couch all day and watching tv. >> reporter: debbie's friend ellen mitchell noticed a change in debbie's behavior when she returned home from business trips. >> she would come home from some of these trips and say, hey, let's go get a drink, let's have some dinner. and your expectation would be, i want to get home to my husband. she didn't seem to be in any particular hurry anymore. >> reporter: looking back now, debbie's parents wondered if the marriage frayed because debbie, a modern woman, wasn't meeting lars' old-fashioned expectations. >> she was not the kind to stay home and bake cookies or walk in the door and serve you a meal, because she'd worked just as hard, too. >> and all these friends, she goes and spends tennis time, does things -- maybe just -- you feel like you're gettin' shortchanged. >> he wanted more of debbie? >> right. >> he did want more from debbie. >> reporter: all marriages have problems.

very few end this badly. so investigators decided to take an even closer look at the husband who pulled the trigger. >> coming up, lars seemed upset. was he? >> these bits of emotion are only done in front of the detective. they're not done when he's alone. helping new customers bundle and save big, but now it's time to find my dream abode. -right away, i could tell his priorities were a little unorthodox. -keep going. stop. a little bit down. stop. back up again. is this adequate sunlight for a komodo dragon? -yeah. -sure, i want that discount on car insurance just for owning a home, but i'm not compromising. -you're taking a shower? -water pressure's crucial, scott! it's like they say -- location, location, koi pond. -they don't say that. copd makes it hard to breathe. so to breathe better, i go with anoro. ♪ go your own way copd tries to say, "go this way."

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an empty commuter plane stolen from seattle's airport crashed late last night on a small, sparsely populated island on puget sound. an airline agent took the plane and was performing stunts before it crashed. two military jets tried to stop the plane but were were unsuccessful. a california has aer warded a school grounds keeper $2 million in damages in his case against monsanto.

the company was found guilty for putting a carsgenic agent in its products. now back to "dateline." >> reporter: as 2015 gave way to 2016, investigators weren't so sure debbie kelly had been happy in her marriage to lars itzo and they took a closer look at the circumstances of her death. >> reporter: they pulled all those recordings from the day of the shooting, examined lars's behavior, his turns of phrase, even things he didn't do. starting with the 911 call. >> reporter: this is lars in the first moments of that call. >> had gun shot. i had thought somebody was in the house -- uh, my wife. >> and you did shot somebody? >> yes ma'am. >> and what is your name, sir? >> my name is lars itzo. ah, man. >> what do you make of this tone from lars? >> he's not really that upset about what he's just done. >> i thought he was havin' more of an aw shucks moment, as opposed to an oh my god moment, "i just shot my wife." >> reporter: but within moments, lars became frantic. >> oh! baby!

>> reporter: hyperventilating, moaning. >> oh, my love. >> reporter: the question, was it for real? >> the way he switched up emotions from when he starts doing cpr, it sounded a lot like mouth breathing. >> to me, it sounded like overacting. >> reporter: and investigators also noticed how lars's story evolved over just a few hours, on the 911 call he set the scene this way. >> i seen a light, a flashlight or something i didn't know what it was. i just seen a light and i heard movement. i thought she was right next to me when i got up out of bed. >> reporter: to responding officers, he changed the order of events -- telling them he saw that light after he got out of bed. >> i got to the door i seen a flash of light coming from the front of the house. >> reporter: and lars added various new details to his

story. >> i seen people right here so i told her to wait here. >> i seen people running. i heard the dog growling. >> reporter: in his interview down at the statement, lars revised his story again. that's when he said he woke to the front door squeaking, and offered, for the first time, this description of how he realized he'd shot debbie. >> i heard this groaning and i knew it was my wife. >> reporter: during those interviews, lars appeared heartbroken, at times falling apart. >> he was described as pacing in the blanket. he was mumbling, he was moaning. >> at various times, yes. >> is that not what a husband should do after something like that? it sounds normal. >> well, that's the thing, it sounds normal, right? but when the detective looks at him and he doesn't see any

tears, okay, that doesn't jibe with everything else. >> these bits of emotion are only done in front of the -- the detective. they're not done when he's alone. >> what was he doing when officers were not watching him? >> he sat in this manner. >> sleeping at moments. >> reporter: and sipping his signature drink, dr. pepper. >> reporter: free on bail, lars understood he was still under the microscope. >> it was difficult. >> he didn't sleep much. >> reporter: watching lars suffer was torture for ken and kristi. they knew how much their brother loved debbie and how dark and confusing that house could be at night. >> you felt it was important that we come to the house now. >> yes, i did. >> why? >> because no one realizes how dark it was. >> we're here. it's around 4:00 in the morning. >> yes, it is. >> reporter: this was lars and debbie's bedroom. >> the bed was on this wall. >> reporter: ken itzo walked us through the story lars told him countless times -- >> he wasn't sure what he was seeing. he just thought it was an intruder, maybe two. >> there's the thought of, well, debbie's only 5'3", she's blonde. she was wearing a light t-shirt. how could he not see his own wife?

>> at 4:00 in the morning. you don't see anything. it's dark. and i don't think size, weight, or complexion matters at 4:00 in the morning, when you're awakened by a noise, and your dog's growling. >> reporter: ken wanted us to experience it with the lights off. >> let's do it. >> so let's shut the light off. okay. >> reporter: at first it was pitch black, but as my eyes adjusted, i could make out something. >> i can see a little bit of a silhouette but i cannot see your face. you wanna turn the light back on? >> i believe i was standing about where lars was standing. you were standing about where debbie was standing. >> i will say, he would be able to see, probably, about the -- the height of the person, if he has similar eyes to me. >> and that depiction means absolutely nothing at 4:00 in the morning. >> what's your reaction to that? does that change anything? >> by her size -- alone, he should've known it was her. a silhouette, i mean, three feet away. he should have known that was his wife. >> reporter: prosecutors

believed it simply was not as dark that morning as lars claimed and said photos from inside the house proved it. >> this is the big picture windows that are there in the living room. the drapes were never pulled back. >> and just circle where the shooting happened. >> it would've -- it would've been over here. >> these are the windows the prosecution made such a big deal about even the curtains are exactly the way they were the morning of the incident. they believed ambient light would have had to have seeped through these windows from neighborhood streets, from homes, even the night sky. >> reporter: prosecutors believed that ambient light was enough for lars to see debbie's silhouette. they factored in his inconsistent behavior, his shifting story. >> when you kind of put it all together, there was nothing accidental about what he did. >> reporter: five months after debbie's death the state made its move. >> had you all kinda thought maybe this was going to go away, since so much time had passed?

>> oh. i was kinda hopin' it would. >> reporter: instead on march 3, 2016, lars itzo was re-arrested. the charge this time, murder. >> coming up -- a very thirsty suspect. >> i enjoy a dr. pepper every now and again. but i don't wanna drink a dr. pepper when my hands are covered in my wife's blood. >> but does that make lars a murderer? when "dateline" continues. for mild-to-moderate eczema, there's eucrisa. it's steroid-free. do not use if you are allergic to eucrisa or its ingredients. allergic reactions may occur at or near the application site. the most common side effect is application site pain. ask your doctor about eucrisa. if you... you have fleas. help protect your pet, home and yard from infesting fleas ... ...with the advantage fleaction plan.

>> reporter: was lars itzo a loving husband who made a deadly mistake? or a killer trying to cover his tracks?

that was the central question as the people vs. lars itzo began in december 2016. the stakes were high. if lars was convicted of murder he could face up to 99 years in prison. if he was convicted of manslaughter, as few as two. >> we never for a second believed that he didn't know who that was standing in front of him. >> reporter: but the prosecutors knew proving intentional murder wouldn't be easy. >> reporter: especially in this case though, where you have someone saying, i did it, i confess, but it was an accident, i love my wife. >> yeah, we were -- we were aware of that and we were willing to accept that challenge. >> reporter: lars's attorneys, david phillips and tamara cochran-may believed their client and thought the jury would too. >> this was simply a terrible accident. >> when i first met lars, i could see his remorse. and after speaking with him, i said, this man didn't do anything on purpose.

>> reporter: the prosecution started off in dramatic fashion. they played lars' 911 call for the jury. >> reporter: as the tape rolled, lars shook and sobbed with his entire body. once again the prosecution wondered, was it real remorse? >> i have small children. i have seen that face before. and it usually involves, just before a dirty diaper. >> reporter: now, that's a first on "dateline." >> he had that expression of bearing down. and he was kinda turning red. and you never saw a tear. >> reporter: next up, the first officer on the scene that night. he testified that lars didn't look like a man who'd been doing cpr on his mortally wounded wife. >> he was clean. >> what do you mean by clean? >> he didn't have any blood on his body. once i saw him doing cpr then he had blood on his hands. >> reporter: detectives told the jury lars put on an emotional display. >> the sobbing noises, you know. >> ever see a tear? >> no. >> reporter: they played that

video of lars at the police station to show how he seemed to keep adding details to his story of the shooting. >> i don't know if i felt her or not, i just reached out and -- >> reporter: and how in the midst of tragedy lars still had the presence of mind to ask for his favorite beverage. >> here you go, mr. itzo. >> i enjoy a dr. pepper every now and again. but i don't wanna drink a dr. pepper when my hands are covered in my wife's blood. he doesn't even seem to take notice of that. >> there was one point in the video where he actually sees it and kinda wipes it -- >> yeah. >> off on the blanket. >> no big deal, whatever. little debbie. that's cool. >> reporter: the prosecution's case revolved around this question. around 4:00 a.m. in a dark house, could lars see well enough to know who he was shooting? liz sevilla, a frequent house guest of debbie and lars's testified she could easily see at night in their home. >> there was enough light coming through the big windows that i

could find my way. >> reporter: and remember, debbie was only about three feet away when lars shot her. prosecutor karl alexander wanted to show the jury just how close that is. >> reporter: what was the experience? >> terrifying. >> reporter: why? >> i'm a gun owner. one of the absolute cardinal rules of -- of using a firearm is you do not point the barrel at anything you do not intend to destroy. ever. i knew it was unloaded but in that moment, my pulse skyrocketed. >> reporter: he wanted the jury to think hard, no matter how dark it was, wouldn't you recognize your own spouse? >> he knows her scent, he knows her sound, he knows her shape. and he knew who that was in front of him. >> reporter: after laying out how lars killed debbie, the prosecution thought the jury would want to know why. what was the motive? the couple, they said, had hit a breaking point. liz sevilla testified that her

hard charging, multi-tasking friend debbie found lars a little too laid back. >> there was always a project. and it was taking a long time. >> and who was doing this construction? >> lars. >> so are you trying to say she was frustrated with lars? >> yes, sir. >> reporter: the prosecutors told the jury this marriage of opposites became too lopsided for lars to handle. >> she took time to play tennis. work was very important. she took time out to go have dinner with friends and family. he wasn't a factor. >> basically, she didn't consider him enough to be a part of her normal, everyday life. >> reporter: they said lars wanted more from debbie. and when he didn't get it, he got rid of her instead. >> reporter: this was a new one for me. one of the possible motives that was brought up, that lars was old school and was upset that debbie did not take his last name. >> she was a professional woman and she was very driven.

and i think that's part of why she didn't take his name. she kept everything separate. >> reporter: including her bank accounts. she never put lars's name on them. >> reporter: this was not about money. >> no, it -- it -- it wasn't. it really has to do with he loved her more than she loved him. >> reporter: when its turn came, the defense said of course lars loved debbie, which is exactly why he did not murder her. lars itzo accidentally shot and killed the love of his life. what he is guilty of is making the most horrific mistake of his entire life. >> reporter: and they called a reluctant surprise witness. debbie's own mother, whose early support for lars had waned. she did not want to testify on his behalf. >> i didn't take it well. i actually started screaming at the attorney. >> reporter: but anne took the stand. lars's attorney showed her a check she once wrote to debbie.

>> who is the check made out to? >> debbie itzo. >> reporter: debbie itzo. proof, the defense argued, that independent debbie sometimes went by her married name. they called lars's friends to say the couple's marriage was solid. >> how would you describe his relationship with debbie? >> perfect. >> it was very good. >> did you ever notice any, sense any marital conflict? >> no. >> reporter: kristi itzo explained how her normally stoic brother was overcome with profound grief. >> he was crying, he was curled up in a ball. he grabbed me, we cried for 20 minutes, and all he wanted was debbie back. >> reporter: but the defense knew their case hinged on one thing -- lars's state of mind the moment he pulled the trigger. >> i need you to raise your right hand. >> reporter: and there was only one person who could tell that to the jury.

>> coming up -- a grieving husband? or a lying one. >> the love of your life? >> yes. >> the person you know better than anybody else. >> yes, sir. >> and you can't tell it's her when you pull that trigger? >> know better than anyone else. >> narrator: when "dateline" continues.

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>> narrator: welcome back to "dateline." on trial for the murder of his wife, lars itzo was about to take the witness stand. what could he say to make jurors believe he simply didn't know that threatening shadow was debbie? here's andrea canning with the conclusion of "the silhouette." >> at the time i knew it was my wife -- >> lars itzo on the stand in his own murder trial, to tell the story of what he described as the perfect relationship. >> it was worst thing that ever happened to me. >> that's what everyone in the courtroom was waiting for, details about the morning debbie was killed. >> i heard a grumbling, and as i woke up, i got up to see what that it was. it was pitch dark. >> lars stuck to his story that

he couldn't see what he was shooting at. he thought their lives were in danger. >> i had seen the movement in front of me and i had pulled the trigger at that time. >> he said he was a good man who made a horrible mistake. >> did you -- at any time? >> no, she was the love of my life. >> a mistake he said he would regret forever. >> she was hurt pretty bad. she would have -- >> on cross-examination prosecutor carl alexander challenged lars' key claim, that in the kadark he simply couldn' distinguish debbie from an intruder. >> you know debbie's shape? >> i know her shape. >> the love of your life. >> yes, sir. >> you know better than anybody else? >> yes, sir. >> and you can't tell it is her

when you pulled that trigger? >> no, sir. >> lars testified for two-and-a-half hours, but would it be enough to convince the jury he was innocent? they now faced a decision between murder, manslaughter or not guilty. after more than six hours, a verdict. on count i, the murder charge -- >> we the jury find the defendant lars itzo not guilty. >> but before anyone in the courtroom had time to react, another verdict. >> guilty of manslaughter as charged in count two of the indictment. >> the verdict pleased almost no one. >> no, this can't be. >> for so many on debbie's side, it was as if the jury left lars off. >> disbelief, anger beyond words. >> but lars' family believed prosecutors had it all wrong. >> it was about them winning. it had nothing to do with justice or the truth. >> then came sentencing. in texas the jury decides.

it soon became clear they wanted to hold lars accountable. >> for a term of 15 years. >> 15 years, just a few years shy of the maximum sentence. i spoke with lars at the state penitentiary in beeville, texas, where he said he carries a photo of debbie in the pocket of his prison uniform. >> i kiss her picture every morning, every night. >> i asked him to skdescribe on again what happened the morning he shot debbie. >> i woke in the middle of the night. >> the story sounded familiar, but then -- >> and i seen the door closing very, very, very slowly. >> he had seen the door closing? as he had before, he added a detail to his story. moments later he added another. >> there were people in my house reaching for me. >> reaching for you? >> well, i just seen movement. >> so i asked lars about his

inconsistencies. >> why was your story changing. >> i don't believe it was. i don't have the script in front of me that i'm reading. this is exactly what happened step by step by step. >> but isn't the truth the truth? >> absolutely. but to have an exact answer every single time, it is not me. i will have an answer that is the truth but it is going to be said differently each time. >> then we talked about the key question, what really did he see before he fired the gun. >> i was in the house. >> yes, ma'am. >> and it was very dark, but i could make out your brother's silhouette. would you not clue in that that could be debbie and maybe i shouldn't pull the trigger? >> i know assailants come in various forms. i didn't recognize that it was my wife. if it was, i would have never

pulled the trigger. >> did you see her silhouette? >> no, ma'am. i seen movement. that was all i seen, was like a shadow moving. the first thing was in my minute, was to protect. >> did you stage this death? >> absolutely not. >> did you murder debbie? >> no, ma'am. my wife was everything. she was great in every sense of the word. >> that offers the kellys little comfort. >> satisfaction would be to have your daughter come back in the door and it is never going to happen. >> what would you like people to walk away with about debbie and her life? >> she was an inspiration. she will also be a part of me, and still is. >> so ambitious, so hard-working, so close to realizing her dreams. >> debbie's tennis friends say they miss her every day. >> i think debbie is all around

us and supporting us, and we find hints of that constantly in our lives. she was a wonderful person. >> and we're blessed to have known her as a friend. >> narrator: that's all for this edition of "dateline." i'm craig melvin. thank you for watching. ♪ i'm craig melvin and i'm natalie morales sneechlt . >> narrator: and this is "dateline." >> she was receiving long, rambling e-mails threatening her life, saying her husband is cheating on her. she's telling her to watch her back, she better get out of the picture. >> narrator: menacing e-mails sent to a newlywed. the new wife went to authorities and said she was being harassed. >> that's when the fireworks started happening. >> obviously this has to stop. >> narrator: what arrived