Could any parent ever do this on purpose . Inside this landmark case. He was everything to me. Everything was taken away from her. Her whole life has changed. A heartbreaking family tragedy. Was it an accident or a crime . She knew what the truth was. There were a whole lot of secrets to be revealed. Yes, maam. Im lester holt. And this is dateline. Heres Andrea Canning with unimaginable. Reporter youre watching as a Police Cruiser races to an atlanta parking lot. A call for help has come over the radio. Child not breathing. Hed been found in the back seat of a hot car. Every year an average of 37 children die from heatstroke after being forgotten or left behind in cars in the heat of the sun. And parents pay the ultimate price for lives that are busy, distracted, sometimes overwhelming. Police werent able to save 22monthold Cooper Harris a few years eeg ago, and his death in hot car made headlines nationwide. New details in a tragic case weve been following, the death of a georgia toddler. Reporter but there was Something Different about coopers story. Something darker. Because coopers dad, ross harris, ended up being charged with a crime. Accused not of forgetting cooper but of murdering him. And his murder weapon of choice, prosecutors said, was a hot car. But even if youve seen the headlines, theres a lot more to this story you may not know. Tonight well take you to the scene, show you Surveillance Footage from that day and give you an indepth look at the evidence. It sent chills down our spines knowing we were in th reporter well also talk to insiders who have never spoken out before. They say ross harris was not a killer but a doting dad. Was he a proud dad . So proud. He loved that boy. Reporter a father who ended up on trial for an unimaginable crime. The entire case was a house of cards. Reporter and just like the people around him, you can decide is this the face of a dad who just made the worst mistake of his life . Or a murderer . Oh, my god. What have i done . Reporter ross harris grew up in tuscaloosa, alabama, and thats where his close friend, billy kirkpatrick, met him. You called him a massive dork . Massive dork, yes. Reporter why did you call him that . Because hes a massive dork. A lot of fun to be around. He remembers one beach holiday in particular. Ross took his guitar and, like, walked up to people on the beach and started conversations because thats who he is. Reporter was he playing for them, too . He was. They didnt ask him to. But he was playing. Reporter but ross seemed to settle down when he met his wife, leanna. She encouraged him to get his college degree. His cousin katie, who quickly became leannas best friend too, says leanna made ross want to be a better man. Weve said that without leanna, ross wouldve probably been a lost little, puppy. Reporter after six years of marriage, they moved to atlanta when ross was offered a job as a Web Developer at home depot. Cooper was born a few months later. What was it like for you, the first time that you that you saw cooper . Oh, man, he was so beautiful, just blonde hair, blue eyes. Just tiny little perfection. I just had this vision of, you know, ross andoo couch and ross is just goofing around with him and get on the floor with him. And its hilarious. Any extra thing that cooper could do, any milestone that he hit, he would share it with everyone. One of the conversations i had with ross, he said that it was so cool that cooper knew his name. And he said, and he loves to yell it at me. So instead of saying dad. He would just go ross. And he would yell ross at him all the time. Reporter it was ross who took cooper to day care most mornings. And that was where leanna expected to pick him up on june 18th, 2014. Here she is arriving at the day care. She got to the day care and cooper wasnt there. Reporter leanna called ross to see if there had been a mixup, but he didnt pick up. And then she had a worrying thought maybe ross had accidentally left cooper at home. She texted her neighbor and asked her to just go look. She has a key to her apartment. Just go look. See if hes there. And she was like, maybe the house will just be torn up. It had be a little toddler tornado when she gets there, but hell be there. Obviously, he wasnt. Reporter leanna rushed over to ross office to see if cooper was there. It was at home depot that a Police Officer tracked her down. Their conversation was recorded as he gave her the worst possible news. There aint no easy way to tell you this. Your child is deceased. Im very sorry to have to tell you that. Where is my husband . Your husband is up at our headquarters right now. Reporter the officer explained ross had never taken cooper to day care that day. That hed done the unthinkable, and left cooper in his car for seven hours in the georgia heat. Has he ever done anything like that, forgetting about no. Do you know what might have made him forget about it . No. I think any parent could put themselves in that situation with their own child. And its so hard to fathom being in a place like that. I think she was in full denial, like, that it wasnt happening. It was a nightmare, is what she said. Im going to wake up and it will be fine. This didnt happen. Reporter leanna was taken to the Cobb County Police headquarters. Ross was already there in an Interview Room, telling detectives what had happened. But to them, something about ross harris and his story wasnt adding up. What really happen that morning . When we come back oh, please, god, why . I didnt mean to. I know you didnt, baby. I know you didnt. Questions about a fathers story. The antennas went up on the detectives when they heard that. And rewards points on all prescriptions, walgreens has you covered. So drop by and seize the savings walgreens. At the corner of happy and healthy. Hdid you get that email i sente wyou. Before you wake up. When life keeps you up. Zzzquil helps you fall asleep in less than 20 minutes. Because sleep is a beautiful thing. Ahyou the law . Weve had some complaints of. Is that a fire . Theres your payoff, deputy. Git velveeta shells cheese. Theres gold in them thar shells. Oohh look a hungry dinosaur muum dinosaurs only eat meat actually the biggest dinosaurs only ate plants country crock has always been made with the goodness of plants. It has real, simple ingredients. And that same delicious taste you love. Real Country Fresh taste, made with the goodness of plants. Welcome to crock country. Ross harris sat alone in the place they call the box, an Interview Room at the Cobb County Police department. Oh, please, god, why . Reporter he could barely keep still as he waited for detectives to question him about the death of his son cooper. He had a horrible story to tell. Ross, just kind of run me through your morning today. Reporter prosecutor chuck boring was brought into the investigation early on. I think the main goal in a case like this is to get a timeline of the events. Reporter ross told detectives the morning had begun like many others. Leanna set off to work early. Ross set out to take cooper to day care and decided to stop for breakfast at chickfila near his office. And me and him do that at chickfila in vinings approximately two or three times a month together. Reporter after they ate, ross said he strapped cooper into his car seat. I gave him a kiss. He gave me a kiss. What i do every time. Its my routine. And just today was just like, careless. I got in my car, and instead of reporter ross told police hed simply forgotten to take cooper to day care. I went to work. As if he wasnt even in the back. And i probably didnt even hear him because he falls asleep really easily when you drive the car. And that was it. Reporter he said he didnt realize what hed done until hours later when he got in his car after work and started driving. I caught a glimpse of him in my when i looked to my right to change lanes. Reporter ross said he went flying into the closest parking lot and pulled a lifeless cooper out of his car. A bystander called 911. Theres a baby on the ground. Reporter dash cam video from a Police Cruiser captured ross at the scene minutes later, pacing, hands on his head. I need your i. D. Wheres it at . Reporter it also captured audio of ross exploding in anger at police. Shut the [ bleep ] up. Hold on. All right. All right. All right. All right. You watch your [ bleep ] mouth. Reporter they cuffed him and put him in a patrol car to cool off. And this was the moment when police started wondering about the way ross was behaving. He cried out one moment. Oh, my god. What have i done . Reporter the next moment he seemed calm. Were going to sit here and talk a little bit. Reporter at the police station, detectives who interviewed ross thought his demeanor seemed a bit strange. They noticed hed never shed a tear in front of them. Instead he was casual as they searched his pockets. Im the lead guitar player at Stonebridge Church in the square. Okay, yeah. Reporter even jokey and english is your primary language . It is. Okay. If not, im doing really good. Reporter prosecutor jesse evans. You look at it and say whatever the reaction is that youre supposed to have, that aint it. Reporter but what really got detectives attention was how much ross seemed to know about children dying in hot cars. The worst fear for me is to leave my son in a hot car. And then, just recently, there was a vet on on the internet who said even if youve got your windows rolled down and regardless, you know, im going to show you how hot it can get in the car. The antennas went up on the detectives when they heard that. Reporter detectives werent in the room when ross was finally reunited with leanna, but the cameras rolled. And ross showed a completely different emotion to his wife. You know i didnt mean to. I know you didnt, baby. I know you didnt. I know that. I didnt mean to. I know you didnt. I think my life is over. Its not over, baby. Its not over. Reporter ross pulled himself together and told leanna his story just like hed told the police. I turned out of chickfila, and i just went to work. Like like it was nothing. He wasnt making a sound. You know, i think he fell asleep. For leanna, too. At least i know that hes in heaven right now. I know he is. I know he is. Hes playing with all the trucks in the world. Oh, my boy. Reporter but it was Something Else ross told leanna that really got the investigators attention. I was up and down, dreading he was going to look terrible. He said it while he was talking to leanna that, you know, he was dreading how cooper was going to look when he got him out. Reporter almost like he knew what was there. Exactly. He knew what was going to be found. Reporter they were also struck by how calm leanna seemed to be. And by this surprising question. Did you say too much . Reporter detectives wondered what she meant. They came back into the room and told ross he wasnt going home. Hes going to jail. Hes being charged. Reporter investigators thought they had enough to prove ross had been negligent by leaving his son in the car. His negligence caused the reporter and their investigation was just beginning. Later that night, when katie reached leanna on the phone, she told her shed been sitting outside her home on the sidewalk. And shes told me that, you know, as long as she sat outside, she could pretend like this wasnt happening. Because once she goes inside, you know, theres an empty bedroom where coopers supposed to be. Reporter an empty crib . Theres his toys, his pictures. Its not real if she doesnt go inside. Reporter katie says leanna was numb without her child and her husband. Did she go through that emotion at any point, im angry at you . How could you do this . I dont know that she was ever angry at him. Reporter because you go through that scenario as a parent, what if my spouse did this . Would i be able to understand . But shes such a composed woman. And her faith, i dont think, would let her be angry at him for something that he did not do intentionally. Reporter as coopers family began to grieve, detectives started building their case against ross harris. And what they found convinced them this was no simple case of negligence. They believed this was premeditated murder. 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Freshness for weeks the day after coopers death, ross harris sat in the cobb county jail. His family and friends were in shock. Billy was a pallbearer at coopers funeral. You have to carry that that little casket. You know . Reporter katie says the family grieved in full view of the media. I felt like it was a circus and we were the monkeys. Everybody was watching us. Reporter police were watching, too. Prosecutor susan treadway. We hao there. We have to review all of the evidence. We have to see where it leads us. Reporter investigators pulled Surveillance Video from the chickfila restaurant where ross said he took cooper for breakfast. There they were, father and son. Nothing really seems out of the ordinary. I mean, this looks like a father and son grabbing breakfast. It doesnt look like a child killer waiting to carry out his crime. I would say completely to the contrary. I looked at the video, and when i first saw it and i thought it seemed very out of the ordinary. In particular, the way that he was introducing cooper to some of the workers there. And how they eventually described it to us as being almost like he was putting on a show, almost like he was going out of his way to do that. Reporter but maybe more interesting, prosecutor jesse evans says, was what the video showed about cooper. Coopers wide awake. Didnt appear to be sleepy or anything like that. Reporter ross had told detectives cooper was most likely asleep in the car, and thats why hed forgotten about him. But dkts were skeptica the entire drive from the restaurant to ross office was only about half a mile. And there was Something Else investigators found interesting about ross route that day. Its how quickly he would have forgotten cooper if it happened the way he said. We decided to retrace ross route that day. Were making a right out of the chickfila parking lot and we have to cross a lane of traffic just as ross did to get to this uturn right here. He made this uturn very quickly and then headed toward this intersection up here. And this is a critical intersection coming up. It was here ross had to make a decision. Going left would have taken him to coopers day care. Going straight on would have taken him to work. He went straight on. That means he forgot cooper was in the car within two minutes of strapping him into his car seat and giving him a kiss. It does seem remarkable that we can forget a child in a car very quickly. Reporter dr. David diamond is a neuroscientist at the university of south florida. Hundreds of cases of children who die in hot cars. In a recent case i was involved in in australia, a mother drove one block, a 30second drive, and in a matter of that brief time forgot that her child was in the car. Reporter what were talking about here, there is actually a name for this. This is referred to as forgotten baby syndrome, which actually describes a phenomenon in which normal, attentive and loving parents, for reasons we dont fully understand, lose awareness that their child is in a car. Reporter diamond says it can happen to anyone. Distraction and exhaustion often play a role. He add, once the child is forgotten, the brain plays a dangerous trick. Whats remarkable about these cases is that these parents actually create sort of an artificial memory that the children are actually at day care and that they are safe. Reporter but in this case, investigators were increasingly convinced that coopers death had nothing to do with a slip of the mind. How could you forget something that quickly. Now, i dont know what was going through this mans mind, but i do know that i have five children and i forget things in an instant. It just happens. Is it fair to say, oh, he wouldnt be able to forget something so fast . This is something that if you look at it alone, can somebody forget something that fast . Is it possible . Yes. But then you look at the location of the car seat and all of the other factors together and that showed us that he could not have. Reporter investigators noted that coopers car seat was just inches from the drivers seat. And when they looked at Surveillance Video from ross work parking lot, they saw this, video of ross backing up before he parked. They were sure ross must have seen cooper when he backed up. We wanted to see for ourselves. Were in the same kind of car ross harris was driving. Weve placed the same model of car seat in the same spot cooper was sitting. If i turn around, i can definitely see it. If i use my mirrors to back up, i cant. And there was another detail the Surveillance Video from home depot revealed. Ross had gone to lunch with some friends. There he is getting picked up. But look here, nearly an hour later, there he is again getting dropped off at his car. He opens the drivers door and throws a box of light bulbs onto the front seat. Ross never told detectives about going back to his car in the middle of the day. Did he lie about going to the car or did he just not disclose that he had gone to the car . I think when you look at it in totality, he absolutely lied about it. Reporter investigators were sure ross was hiding something. They believed there was no way he could have opened that door and missed his son in the back seat of the car. Did you consider the possibility that maybe he really did just throw the light bulbs in there and didnt see cooper . Absolutely, but when you look at Everything Else in the case, reporter and that Everything Else included what investigators uncovered on ross cell phone. There were a whole lot of secrets to be revealed . Yes, maam. Coming up ross hair iz, devoted family man . Just incredibly loving and doting. Or deevous facade . Did you engage in sexual acts with him . Yes, on three different ocassions. This guy clearly was leading a double life. Hows that for unlimited . And now, find out how to get a free iphone se from sprint. For people with hearing loss, visit sprintrelay. Com. Moroccan infusion for shine and new honey infusion for strength. Find the blend you need for the hair you love. Suave professionals works as well as salon brands. For the first time ever. G to the next level, at olive garden. Never ending classics starting at 11. 99. Switch it up between never ending helpings of your most loved classic dishes. Because the best things in life should be never ending. At olive garden. Fios is not cable. Were wired differently. Which means we can deliver internet speeds differently. Welcome to 8 and a half maple street. Its half a house. And even though it only has half the headroom, half a hallway, half the closet space and a half bath, its a full house to the wilsons. Because they have fios, the only 100 Fiber Optic Network with uploads as fast as downloads, their half house has full internet. Cable only offers upload speeds that are a fraction of their downloads. Now you might think its a little odd that the wilsons have a half house, but they think its a little odd to pay for uploads that arent up to speed. Get 150 meg internet with equal uploads and downloads, tv and phone for only 79. 99 per month online for one year. Cable cant offer speeds this fast at a price this good. Only fios can. Y25eiy y16fy police were suspicious of ross harris from the moment they met him on that first terrible day. But their next discovery would turn this strange case into an explosive one. Police seized his phone and computers. And thats when they found the photos and texts. This guy clearly was leading a double life. Reporter investigators found a sordid stash of sexually explicit online chats and texts women, one as young as 15. And whats more, some of the sexual chats happened on the very day cooper died. He was communicating with a woman right. Reporter ten minutes before he left with cooper . Right. We were able to determine that he had been messaging at least six different women throughout that day, sending pictures of himself, asking for photographs. Reporter prosecutors believed ross harris was in the grip of an escalating obsession with sex. And they came to an awful conclusion. That ross wanted so badly to be rid of the constraints of family and fatherhood, he decided to kill his own child. Does being a creep with women make him a child killer . Absolutely not. In this case, though, it showed us the extent to which he was living the other life. It showed us how it had overtaken in his life what was important to him. Reporter so they threw the book at him. Ross was indicted for malice murder, the first person ever to be accused of using a hot car to intentionally kill a child. Stunning and damning new details emerge. Reporter the case became a media sensation with more revelations. Investigators said ross had done Internet Research on hot car death and even visited an online forum for people interested in living a childfree life. A monstrous pore tras was emerging. But even after weighing all the allegations, ross friends were still convinced he never meant to hurt cooper. Did you ever hear ross get frustrated with cooper . No. Reporter treat him like he was a burden at times . No. Reporter because you know there are times when kids can get on our nerves. No. No. There are times when you definitely need a break. Okay . But he loved that boy. Reporter ross Harris Family enlisted the help of defens and his team. The entire case was a house of cards. We felt that, despite public sentiment, and despite the bravado of the state and the charges, we felt extremely confident that that house of cards was going to collapse in trial. Reporter in october, 2016, more than two years after the death of his son, ross harris went on trial for murder. Death. Deception. And a double life. Reporter chuck boring, the lead prosecutor, told the jury why ross story had never added up. That chickfila video showed cooper wide awake. That drive that was too short to forget a toddler. The car seat was just inches behind ross. And at ross office there was a photo of cooper and a gift from cooper. He even sent a text to leanna in the afternoon about cooper. When you getting my buddy, it said. There was just cue after cue after cue that if he had actually forgotten would have triggered something. Reporter and then the prosecution showed what it believed was powerful evidence that ross had to have known that cooper was still in the backseat. That video of ross returning to the car. Why would ross harris return to the scene of the crime . We know, first of all, doing this job enough, people do return to their scene of the crime. Once he went into the car, he realized either this child was still alive or this child was dead and he couldnt take what he had done and he threw the light bulbs. Reporter and prosecutors dissected ross behavior later that day. Witnesses at the scene testified his reactions were off. Did he ever ask to be with the child or ask to hold the child or anything like that . No, sir, not that i recollect. Reporter prosecutors pointed out that when ross got into the patrol car he complained about, of all things, the heat in the back seat. Feels like im not getting heard that ross seemed disconnected from his sons death, they also heard he was obsessed with the sexual contacts hed made outside his marriage. A parade of women took the stand. A woman ross had said he was in love with. Another women he met at his home. We had sex. Reporter and a prostitute. Did you actually engage in sexual acts with him back in may of yes, on three different occasions. Reporter this witness is one of the six women ross was communicating with the day he says he forgot about cooper. And at 5 46 a. M. , within 17 seconds of your messages, did he respond . He did. Reporter did you have to consider the fact that maybe all these women were causing a distraction for ross, which then led to what happened versus that the women were actually a motive . Oh, absolutely. But when you look closely at the content of the messages and whats going back and forth specifically youre trying to prove to a jury that this person had the intent in his mind to kill his child. You have to get to know that person. You have to get to know what theyre made of. Reporter and prosecutors say one message in particular said it all. Just minutes before ross strapped cooper into his car seat for the last time, he messaged a woman on an anonymous app called whisper. He typed this. I love my son and all, but we both need escapes. Honestly, it sent chills down our spines knowing we were in the head of a murderer. Reporter nonsense, according to the defense. If he is in the throes of committing a heinous murder, is he really going to announce that by texting it through this application right in the middle of doing it . Reporter ross defense team says the entire case against him was outrageous, built on evidence that was twisted by prosecutors to make him look like a killer. They say that message about ca hanging out with friends, not killing his son. If you take that one message in isolation, you can make it mean all kinds of things. Reporter another case in point, that childfree website ross supposedly visited . He actually found it repulsive. The link was sent to him by a friend in jest. Ross goes to the link, looks at it, and he responded, grossness. Reporter and the defense says there was more misinformation released early on, like that story about ross researching hot car deaths. Ross had clicked on one video posted on a popular website about pets and hot cars, but the defense said that was hardly research. A computer expert testified ross never actively searched for information on hot car death. I didnt see him searching for anything at any point in time that would have been how to kill a child in the car or hot car deaths or anng reporter as far as his return to the car that day . The defense says ross had no idea his son was in the back seat. Never even glanced inside as he tossed the light bulbs onto the front seat. Look at this angle of the video. The proof was his head never got below the roof of that car. The proof showed that he was turning in the other direction. Reporter but what about a those reminders during the day . Shouldnt one of those have triggered his mind to say, wait. Cooper. Wheres cooper . I think thats a fair question to ask. If ross had forgotten that he had a son, seeing a picture of cooper would have reminded him that he had a son. He didnt forget he had a son. Once ross slipped into his work day, he had every reason to believe that cooper was at the day care. Reporter as for those witnesses who said ross seemed detached, they didnt know him, the defense argued. So they called people who did, like his friend billy. In my opinion, he was just incredibly loving and doting. Reporter a colleague from home depot. When cooper was born its all he would talk about. Reporter even prosecution witnesses wound up vouching for ross as a good dad. A teacher from coopers day care. He would just spend quality time with him interacting with him doing the activities. Reporter and some of those women who testified for the prosecution about sexting with ross . Even they agreed he seemed to love his kid. What would he say about his son . That he was great, and that he loved his son. He just talked about how much he loved him and how he would never do anything to hurt him and that kind of thing. Reporter but the woman who should have known ross harris best was about to take the stand. She had something to say about the man who betrayed her, and left her son to die. And it may be the last thing youd expect to hear. Cooper was the sweetest little boy. Heartache laid bare. Coopers mom tells her story. I just kind of went into a panic. Would she help her husband or hurt him . You ruined my life. He destroyed my life. Crying or laughing that doesnt match how you feel. It can happen with certain neurologic conditions like stroke, dementia, or ms. He prescribed nuedexta, the only fdaapproved treatment for pba. Tell your doctor about medicines you take. Some cant be taken with nuedexta. Nuedexta is not for people with certain heart conditions. Serious side effects may occur. Lifethreatening allergic reactions to quinidine can happen. Tell your doctor right away if you have bleeding or bruising. Stop nuedexta if muscle twitching, confusion, fever, side effects may include diarrhea, dizziness, cough, vomiting, weakness, or ankle swelling. Nuedexta made a difference by reducing my pba episodes. Ask about nuedexta and go to nuedexta. Com a new epic flavor. Its cranberry. Its pineapple. And theres no. Sugar. Added. Cranberry pineapple 100 juice. The next big thing to hit the juice aisle. Cramom washed our clothes. Uice. Credibility as handymen. One wash with tide pods and were right back where we started. We look like catalogue models who trusts a clean handyman anyway . We cant look this good dinge is the dirt the bargain detergent cant get to. Tide pods can. If youre gonna make an entrance. [car driving upon the water] Leanna Harris had lost so much her child and her life as she had known it. By the time ross went on trial, leanna had heard all the revelations she could stand, and she had divorced him. If anyone had a reason to hate ross, to be angry at ross, to not get up on that witness stand for ross, its her. Right. Reporter but yet she did. Because she believes 100 that it was not intentional. Reporter so there she was in court, not condemning ross, but defending him. Tell these folks a little about cooper. Cooper was the sweetest little boy. He had so much life in him. He was everything to me. Reporter and everything to ross, too, she testified, as the jury watched family videos of father and son. What are we looking at there, leanna . Thats just them in the bed. And thats just kind of a little game that they would play. Reporter leanna said ross was the kind of dad who always played at the park. Go. Reporter and made goofy videos of his son at snack time. You want it . Yeah. Did ross love his little boy . Yes, he did. Very much. Did you ever see ross express anger or hatred or malice toward his son ever . No, never. Reporter then came that terrible day. The courtroom was silent as leanna described arriving at coopers day care and being told he wasnt there. She said, he didnt come today. And i just kind of went into a panic. I was just it didnt make sense. Cooper was supposed to be at day care. I was supposed to be the one to pick him up. It didnt make sense. The only thing that made sense to me, based on everything that i knew that day, ross must have left him in the car. Reporter it made sense because she knew ross so well. He could be forgetful. And when she saw the video of him with police, she recognized that ross, too. This morning we woke up reporter the overlysocial guy just chatting away. He just would talk to everybody, very outgoing, very vocal. He didnt he never met a stranger. Reporter but leanna also told the jury how ross looked when she first saw him at the police station. She says he was in terrible pain. Him like that. Reporter this was the true face of ross grief and guilt, the defense said. And leanna explained to the jury why she asked ross that question that made investigators so suspicious. Did you say too much . I couldnt understand what was happening. I didnt understand why he was being charged. And the only thing that i that i could think in my head was what did you say . And so those words came out. Reporter as for that prosecution theory that ross had wanted to escape his family for his secret life, leanna said it wasnt true. Shed known for years that ross had a problem. I came home from work one day, and he told me that he had a problem with pornography. Two years after that probably, i found a message on his phone that i guess you would describe it as sexting. Reporter she said they worked hard to save the marriage, and if ross had wanted out, all he had to do was ask. I just very bluntly one night said, do you want a divorce . I mean, if you want a divorce, you can have it. I will give it to you, if thats what you want. And i believe his answer back to me was, thats the last thing i want. Reporter prosecutors told us there was no evidence leanna knew what her husband was supposedly planning. And when they crossexamined her, they suggested she didnt know her husband at all. Youd agree theres a whole part of his life that you had no clue about . I would agree that i did not know the depth. Have you read the Text Messages that he sent to these other women . No. I have no i have no reason to haea okay. So if hes saying foul things to a 15yearold girl, you wouldnt think that that was Something Different than the way he portrayed himself to you . I think its horrible. Reporter the prosecutor pointed out that ross lied to her all the time. One example did you know that was the afternoon he actually called a prostitute and went to have sex with her instead of being at home with you and cooper . I didnt know that. Reporter humiliating as it was, she stuck it out for nearly two days of testimony. That woman had every reason in the world to hate ross harris. And despite all of that, despite all of that, she was willing to come testify for him because she knew what the truth was. Reporter and then, in his final question to leanna, ross attorney wanted to make something clear. Leanna was there for one reason only she believed that what happened to cooper was a mistake, not a crime. Away. How do you feel about your exhusband . He ruined my life. He destroyed my life. Im humiliated. I may never trust anybody again the way that i did. If i never see him again after this day, thats fine. Nothing further, judge. Coming up ross harris is an innocent man. The death of Cooper Harris. Accident or murder . He was very loved by everyone, especially his parents. The jury has its verdict. The ancestry dna results were really specific. They told me all of these places in west africa. I feel really proud of my lineage, and i feel really proud of my ancestry. Customer service d. Maam. 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At the corner of happy and healthy. Ross harris, the man whose exwife says never met a stranger, was about to have his future decided by 12 of them. How were you all feeling as the jury went out to deliberate . I didnt think there was any chance of them coming back with guilty on anything that had to do with cooper. Reporter ross cousin katie said nothing she had seen at trial had swayed her belief in ross innocence. You could hold a gun to my head and tell me that i had to say that ross hurt cooper on purpose, and it will never come out of my mouth. Will never come out of my mouth. Reporter ross best friend billy was equally confident. The prosecution did not do well at all. They did not prove motive. I mean, they didnt get close to it. In fact, i feel like their witnesses could have been defense witnesses. Reporter the jury took its time to deliberate the charges. Not only multiple counts of Child Cruelty and murder. Ross also faced charges related to exchanging sexually explicit images with a minor. One day passed, then two, then on the fourth day word came. A verdict. We, the jury, find as follows, count one, malice murder. As to count one we find the defendant guilty. Reporter guilty on all counts. Im sure youll never forget that moment. Its ludicrous. Its insanity. Reporter what would you say to the jury . Im disappointed. I dont feel like they did their job. Reporter we wanted to know how the jury reached its decision. None of the jurors would speak to us on camera, but one did tell us they paid close attention to that video that shows ross harris returning to his car at lunch time. In fact, the jury wanted to reexamine the video during deliberations. The juror also told us that in his heart of hearts he bve son. The prosecution says the jury got it completely right. But hearing the word guilty was no cause for celebration. What i wanted to hear most is, you know, we can bring cooper back. You cant get that from it though. Reporter three weeks later, a judge sentenced ross harris to life in prison. Sentence of the court is life to serve in confinement without parole. Reporter his defense team has already filed an appeal, arguing among other things that the judge never should have allowed all that testimony about sex into the murder trial. And the defense says inaccurate information released early on about ross computer searches made it impossible for him to get a fair trial. Our personal belief, not lawyer talk, our personal belief and knowing ross and knowing this case better than anybody in the world, ross harris is an innocent man. Reporter are you going to this case is far from over. Reporter having seen the appeal, vic reynolds, the top prosecutor in cobb county believes it wont change the outcome. I have complete confidence in the jurys verdict, complete confidence in the evidence that was presented, and i believe when the day comes, this verdict will, in fact, be affirmed. Reporter but ross harris supporters say there is another tragedy in all this. They believe his conviction will make things worse for parents who make similar, terrible mistakes. This sets the precedent that anyone that does this is a monster. And thats just not the case. This really can happen to anyone. Reporter coopers family may never stop grieving for the little boy who had just learned to say his dads name, loved his trucks and loved to smile. What does leanna want coopers legacy to be . That he was loved. He was very loved by everyone that knew him, especially his parents. Of dateline. Well see you tomorrow at 8 00, 7 00 central for the dateline for all of us at nbc news, good night. Now at 11 00, investigators working through the night in a Northern Virginia home. Three people found dead inside. 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