it has to be hard on him. and so i always -- i always pray to make sure that he knows that even though his mother's not there, she loved him more than anything. anything > she was crying and crying. i said, "what's wrong?" and she says, "debbie's dead." we all wanted to believe that it was an accident. there's no possible way he could do this on purpose. >> a dark house, a husband with a gun. wife dead on the floor. >> make sure that she is still breathing. >> oh, i don't think she is, damn it. >> there was no question who killed her. the mystery was why.

>> i hear the door squeaking, and i hear the rumbling and i hear the dog growling. >> how could you not tell that's your wife? >> it was dark. >> he just kept saying it was an accident. he said he didn't do anything wrong. >> others disagreed. >> we never for a second believe that he didn't know who that was standing in front of him. >> was it a tragic mistake? >> he was broken. >> or cold-blooded murder. >> it's only done in front of the detective. >> a room too dark to see? >> shut the light off. >> or a story too hard to believe. >> there was nothing accidental about what he did. >> a shot in the dark and dealt in the light of day. >> the love of your life. >> yes, sir. you know better than anybody else. >> yes, sir. >> and you can't tell it's her

>> 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. with this one little nexgard chew comes the confidence, you're doing what's right, to protect your dog from fleas and ticks for a full month. it's the #1 vet recommended protection. and it's safe for puppies. nexgard. what one little chew can do. how do you keep feeling your best all summer long? start with supporting your gut health. only activia has billions of our live and active probiotics. so, let's make this the summer of loving your gut. activia. love for your gut. actually, that's my buick.

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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. >> [ bleep ] damn it! oh, baby! ugh. oh, man! right in the freaking chest! oh! >> reporter: police raced up to the house, dash cams rolling. the audio kept recording as they entered the house. [ dog barking ] >> help me! >> reporter: they found lars standing over debbie's body back by the bedroom. >> 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. >> okay. >> i grabbed my shotgun. >> reporter: as emts took over, trying to save debbie, lars went with police down to the station. they urgently needed more details. >> reporter: 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' 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.

>> 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. >> 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 debbie, not debbie, 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? >> he 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.

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 debbie 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 debbie, 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. >> he starts changing in terms of my conversation, connections with him. and he's not so forthcoming. 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. hole. >> 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. >> 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? here's your buick sir. actually, that's my buick. your buick doesn't have a roof rack! this is my buick. how are we gonna fit in your mom's buick? easy. i like that new buick. me too. i was actually talking about that buick. i knew that. did you? buick's fresh new lineup is full of surprises. during buick's fourth of july sales event, pay no interest for 76 months on most 2019 buick models.

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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' 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' 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 station, 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 jive 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. 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. 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 3rd, 2016, lars itzo was re-arrested. the charge this time, murder. coming up -- >> here you go, mister. >> 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. i like that new buick. me too. i was actually talking about that buick. i knew that. did you? buick's fresh new lineup is full of surprises. during buick's fourth of july sales event, pay no interest for 76 months on most 2019 buick models.

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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' 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. 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. 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' name on them. 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' 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' 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, sir. >> the person you know better than anybody else. >> yes, sir. >> and you can't tell it's her when you pull that trigger? then i heard a moaning. is a game changer. it's going to let the dentist offer their patient sensitivity relief in 3 days. say over the course of a weekend you're going to start feeling significant results. this is jamie. you're going to be seeing a lot more of him now. -i'm not calling him "dad." -oh, n-no. -look, [sighs] i get it. some new guy comes in helping your mom bundle and save with progressive, but hey, we're all in this together. right, champ? -i'm getting more nuggets. -how about some carrots? you don't want to ruin your dinner. -you're not my dad! -that's fair.

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and at that time i knew it was my wife. >> reporter: lars itzo, up on the stand in his own murder trial. to tell the story of what he described as the perfect relationship. >> it was bliss. uh, the best thing that ever happened to me.

>> reporter: then 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 was. it was pitch dark. >> reporter: 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 a movement in front of me, and i had pulled the trigger at that time. >> reporter: he said he was a good man who made a horrible mistake. >> did you in any way intend to cause debbie any kind of injury?

>> no, she was the love of my life. >> reporter: a mistake he said he would regret forever. >> okay, it still hurts? >> every second of the day. she was sent to me from god. if i could have made a list, she would've checked every box. >> reporter: on cross examination prosecutor karl alexander challenged lars's key claim -- that in the dark, he simply couldn't distinguish debbie from an intruder. >> you know debbie's shape. >> i know her shape, yes, sir. >> 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? >> no, sir. >> reporter: 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 one, the murder charge. >> we the jury find the defendant lars eric itzo not guilty. >> reporter: but before anyone in the courtroom had time to react, another verdict. >> guilty of manslaughter. >> reporter: the verdict pleased almost no one. >> no, this can't be. >> reporter: for so many on debbie's side, it was as if the jury let lars off. >> disbelief, anger, beyond words. >> reporter: but lars' family believed prosecutors had it all wrong. >> it was about them winning. it had nothing to do with justice or the truth. >> reporter: then came sentencing. in texas the jury decides, and it soon became clear they wanted to hold lars accountable. >> a term of 15 years. >> reporter: 15 years, just a few years shy of the maximum sentence. i spoke with lars at the state penitentiary in beeville, texas, where he says he carries a photo of debbie in the pocket of his prison uniform. >> i kiss her picture every morning, every night. >> reporter: i asked him to describe once again what happened the morning he shot debbie. >> i was awake, awoken in the middle of the night. >> reporter: the story sounded familiar at first, but then -- >> and i seen the door closing very, very, very slowly. >> reporter: he'd seen the door closing slowly? as he had before, lars just added a new detail to his story. moments later, he seemed to add another. >> believing that there were people in my house reaching for me. >> reporter: reaching for you? >> well, i just seen movement. >> reporter: so i asked lars about his inconsistencies. why was your story changing? >> i don't believe it was.

i don't have a script in front of me that i'm reading, this is exactly what happened step by step by step. >> reporter: but isn't the truth the truth? >> absolutely, but to have an exact answer every single time, that's not me. i will have an answer that is the truth that is gonna be said differently each time. >> reporter: then we talked about the key question, what, really did he see before he fired the gun? >> i was in the house, 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've never pulled the trigger. >> reporter: 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 mind, was to protect.

>> reporter: did you stage this death? >> absolutely not. >> reporter: did you murder debbie? >> no, ma'am. my wife was everything. she was great in every sense of the word. >> reporter: that offers the kellys little comfort. >> the only real satisfaction would be have your daughter come back through the door, and that's never going to happen. >> reporter: what do you want people to walk away from watching about her and her life? >> i think debbie was an inspiration. she will always be a part of me and still is. >> reporter: 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 presence.

>> and we're blessed to have known her as a friend. >> that's all for now. i'm craig melvin. >> and i'm natalie morales. >> this is "dateline." >> how do you feel that so many people think that steven avery is innocent? >> it's emotional. they made him look like he was a nice person. what's happening is wrong. >> the evidence is beyond overwhelming. steven avery is guilty. >> i'm innocent. >> the story gripped the nation, in the series, "making a murderer." >> so many americans have learned about it. >> it's being heard around the world. >> steven avery and his nephew convicted of murder in the