Entire world around him. But is his wife just being mad. No, no, no, no, no. I know for a fact i let it go. Or go mad . My wife has a long history of mental imbalances. She was a train wreck waiting to happen. This is really freaking me out. The pa media, obsessed. This woman was murdered. And two days of crucial tape missing. Heres a man waiting for a crime to happen every day, and one finally happens. He has no pictures of it. What happens after an autopsy on the computer . It was bold. Tonight, haunted by the case. I made a promise to myself, i would never give up. The suspects daughter defending him, taking their crusad crusade public on youtube. My father is telling the truth. And how it gets stalled by a voice from the grave. I dont want any part of this freaking family anymore. What the camera didnt see. Good evening. Im elizabeth vargas. Welcome to 20 20 saturday. Im david muir. Right here tonight, is the case of a father trying to protect his family, or simply wanting to watch their every move 24 7. That verdict is now being appealed. Heres what we want to know. What do you think . Is a new trial warranted . Crucial evidence centered on those recordings taken from a command center right inside the home. Thousands of recordings that took investigators a year and a half to review, but where are the missing tapes . Could they solve everything . Heres jim avila. Reporter what would we see if your home was being watched inside and out 24 hours a day by 21 surveillance cameras . Watching as you sat on the couch in front of the tv, unblinking as you sneak outside for a smoke on the porch. Show me where you saw cameras. If you see the front door to the right of it, basically, up in the corner, there was a camera up there. From the top, on the back corner of the house. Reporter welcome to sydneys cove. A quiet called sack in lawrenceville, georgia. Bells of the Baptist Church can be hard in the backyard. And dinner time is marked by the rumble of the freight train. Its home to matt and nikky lively, and their children. Why all the cameras . Matts in the business. He sells security systems, a tech savvy law and order guy when has become a oneman neighborhood watch. We sat down with her family. Her father, her daughter and sister, amy. I knew that there were cameras all over the place, because i mean, he made it a point to sort of brag about it really. It was sort of a source of pride for him. Reporter the house seems so tranquil on the outside. Matt and nikknikky, both 44 yea old, married on valentines day, together 14 years. She was southern, an account, the bread winner. Matt, a new yorker, called her baby cakes. Nikky told me that she was in love with him. Their daughters now teenagers, posted this Youtube Video of the trip to hawaii to frolic in the sun. My mom surprised by dad while they were down there, and renewed their vows. She is happy, they were in love. It does sound like people in love, and care for each other do. Reporter but just like hawaiis famous volcanos, this love affair is about to blow in the dark of night, and thanks to matts over the top obsession, we hear it all. Before i breaking this [ bleep ] office. Im going to start breaking this. I know you are. I know you are. Reporter that Steel Magnolia plus size voice belongs to nikky, 93 pounds soaking wet. Matt is a giant oaf of a man. Big enough to lift his tiny wife with one hand. On some of the recordings, he he sounds like a punching bag. I cant keep doing this. Youre un[ bleep ] believable. How you can talk to me lower your voice. Lower your voice. How i spend my time. Reporter the reasons for their fights might sound familiar. Money and sex. They are 300,000 in debt. Their love life, troubled. They are see a counselor. Pick it up. Im saving this manrriage. The problem that you want is not me, and not us. Reporter matts surveillance business has become his obsession. Watching, always watching. The porch cams, the yard cams. The driveway cams. All diligently documenting the nonevents of daily life. He has the systems the military would be jealous of. Were talking about a huge server bigger than what we would have at the police station. Reporter alex moved out at 16 because she couldnt get along with her dad, and she left her halfsisters behind. It was uncomfortable. He had a camera in the living room, and you were being monitored. But matt insists there was a reason for all that surveillance. He was worried his wife had become mentally unstable. Im going to protect my child, and make sure youre not a raving lunatic first. You dont need to protect them from me. Reporter worse, she had a habit of storming off. Get the blk [ bleep ] out of my way. Can we compromise here . Well, i propose you calm down for a moment. If in a clear head, you want to leave, im not going to stop you. Good. Reporter now matts afraid nikky might run off in a rage and get hurt. To deal with that, he turns to another of his tech skills. Hidden audio recorders. In her purse, in her car, and using her cell phone to track her. Heres matts explanation. Im recording my wife and i have a tracker on her, you know . I have to find my wife every time she runs away. Aye not some overpossessive freak. Reporter the girls still living in the house are witness to the constant marital battles. In that Youtube Video which will play a big role later, they say their mom was the problem. She was acting crazy. She was saying how she was tired of the voices telling her that people were talking bad about her, and she was tired of the voices telling her this, and the voices telling her that. Reporter that was june 28, 2011. Nikky calls 911. Documentation of what matt says he fears. She is running away from home, and he is trying to stop her. My husband refuses to let me leave the house. My wife is yelling and screaming me, and just woke up the children. Doesnt the cops here . I think my wife is throw a tantrum. Let me have her tell me that. Pick up the phone, or else they will come. You dont need to comp. I have them dispatched. Thank you, maam. Youre welcome. Reporter the cops come by to make sure things are under control, but nikky doesnt even look at the officers. Thats her bag, packed and ready by her side. Later that day, she takes it and leaves. And within hours, matt has her then 12yearold daughter, amanda, call and beg her not to stay away. Its haeartbreaking. Hey, mommy. How are you . Good. Mommy, we need to go on vacation. All of us as a family. We need to save this family. Reporter the family doesnt go on vacation. Nikky comes home. They stay at sydneys cove behind closed doors with those cameras rolling. Things seem to be getting back to normal. The family saved for two weeks until a july night, that small figure on the screen is nikky. Its date night with matt. Dinner and a movie. And later that night, the lilys surveillance camp show a smoke before bed. We cant tell, but this cigarette is not the only thing smoldering that summer night. Nikky is about to disappear. When we come back after 13 years of marriage and thousands of arguments, nikky is finally gone for good. And her husband says its because she is crazy. Where is nikky, and what do all those cameras say about her disappearance . St announcer 20 20 saturday continues with what the cam are didnt see. Reporter a hardworking spit fire of a woman, nikky lily, mother, bread winner, a whom who despite her size, takes nothing from her outsized husband. Now she is missing. Nowhere to be found in her familys upscale house outside atlanta. We can go inside with video obtained by abc news. Any clues that answer the question, where is nikky . Go ahead. Look around. See any signs of a violent struggle . Bloodstains on the carpet . Broken furniture . Theres a gun in a holster, but its not smoking. Nothing more incriminating that an unmade bed, and theres the fortress. Yet someone so concerned with the comings and goings in and around his house, matt waits two days before bothering to pick up the phone and call her sister, amy. He said, have you talked to nikky . I said, no. Why . Whats going on . He said, she is missing. I said, are you serious . Call the police. Reporter after that call, matt did file a missing person report and told his story to police. He and nikky had a fight. He slept on the floor of his office, and when he woke up the next morning, nikky was gone. He says the only thing she took was her toothbrush. Her purse, her phone, all the tracking devices left behind. I go upstairs see whats going on. Shes not there. Reporter he says she has been breaking down mentally for some time, and just walked away. This is the weirdest thing, okay . This is really freaking me out, okay . This is not the first time she has run away, but she has never been gone overnight. Reporter matt overshares with the cop on the phone telling him the fight is about sex in detail. On the way home, i said to her, you know, hey, you know, because i wanted sex, but the sex we have been having wasnt anything special, you know . So i said, how about you put on an outfit . That might have set her off. Reporter he said, maybe she is in a hospital suffering from a breakdown. My wife has a long history of some kind of mental imbalances. Okay . Reporter now matt says he has had enough. He is done with his crazy wife. I told her if she doesnt straighten up, im going to divorce her. I saw an attorney about it yesterday. Reporter thats right. Before police have even launched a search, and before matt spread the word that nikky had gone missing, he had hired a lawyer to divorce her. What was that about . I couldnt tell you. My response to, that and reaction to that was, who does that . It was all about him. It was never a frantic, where is my wife . Reporter as if divorce is not enough of a threat, matt goes down to the courthouse to fill out paperwork to have nikky committed. Here he is telling his brotherinlaw about it. I was at the courthouse swearing out a warrant for niqwu for involuntary committal. Reporter a multigenerational civil war is breaking out with matt and his young daughters about the southern inlaws, and her daughter, alex. My mother was the farthest thing from crazy you could get. Her family has a different take. Reporter and they are angry that matt took two days to tell them she is missing. She wasnt worried at all about finding his wife. She was concerned about making sure that he stred the story that she was insane. Reporter so a week after she vanished, he helps organize a search, in order to get the community involved. More than 100 volunteers, all in red spread out through the neighborhood. Matt was not among them. Skipping what may have been the shortest search in the history of missing persons. Ten minutes after friends and family had formed the grid i saw a huge, big pile, and it looked like it was covering up something, so i started kicking away at it, saw her body and her hair. I heard somebody scream from the woods, and i you know, so i went up there to see what they had uncovered, and it was my sister. Oh, dear god. Family members cry out as a were roping this area off. When firefighters and Police Arrive after minutes looking for niqwe lively. I blacked out. Reporter she was found nude, less that a mile from her house. If she was running away, she didnt get far. Her body covered in leaves. Reporter the fingerpointing began. This is amy moments after her sisters body is found. He waited two days to even report her missing. And he told me they had a huge fight and that, you know, she wasnt well, and she had been having graekdowbreakdowns, but r two weeks ago, and she was fine. Reporter the search is closed, but is this murder . The investigators are talking with her husband, and searching the couples home, but police say right now, he is not a suspect. Reporter certainly, matts personal setup will prove he had nothing to do with his wifes disappearances. What better alibi witness than 21 cameras . Heres a man waiting far crime to happen every day. Sitting in his office, looking around. One finally happens, and you have no pictures of it. Correct. Reporter when we come back when the cam announcer 20 20 saturday continues with what the cam aer didnt see. Once again, jim avila. Reporter take a good look at this image of nique leili on her porch. Hours before she supposedly walked out on her husband matt. Its the last picture of her alive. Because, believe it or not, in this house tricked out like a small casino with 21 cameras, none of them managed to capture a single image of her final exit. So did you as an investigator think, well, this might be easy . Theres cameras all over the place. Hes got a recorder here. You might get some evidence off of this. Correct. And did you ask him, can i see the night . He stated that when he came back to his office he realized the system was turned off. Reporter cue the chorus. How convenient and suspicious. The most puzzling tape gap since watergate. Only this isnt just 18 minutes. Its two days worth of critical video, nowhere to be found. You would think wed have it on video. I mean, this guy was serious about his video surveillance. Reporter matt leili tells police that after his wife had that cigarette on the porch the last time she was ever seen on the night of july 8, 2011, his elaborate Monitoring System designed to watch every move simply went dark. Matts theory she stopped by his office where he was sleeping on the floor and pulled the plug on her way out the door on her crazed walk into the night. He said she turned off the system. Reporter without him knowing it . Correct. Reporter even though hes in the room . Correct. Reporter getting no help from matts cameras, investigators turn to niques body under the branches. The bodys telling you something else. Yeah, the bodys definitely telling us that she didnt walk there. Were working this as a homicide. Reporter then there is the condition of her bare feet. Thats something thats very telling of, you know, of a body being placed is the clean feet because if youre running around the neighborhood, youre going to get cuts. I mean, these were pristine. The nail polish is clean and not nicked up. Reporter after an autopsy, the toxicology report reveals a tantalizing new piece of evidence about niques last hours. In her system they find high levels of ghb, the date rape drug. In hundreds of cases, accidentals, overdoses, homicides, suicides, ive never seen ghb in a toxicology report. So that caught my attention immediately. Reporter remember, matt told the police the big blowup that night was over sex. He wanted it, she didnt. But now theres evidence, somehow he had his way. Something he failed to mention in his phone conversation with the cops. I said, listen. Okay, this has gone on far enough, all right. Ill go downstairs, once again, and sleep on the couch. You go to sleep. Well talk about this in the morning. Reporter but the autopsy is most notable for what it does not reveal, the georgia summer is a killers accomplice. We dont have an indication at that time, because of decomp and seven days out in july heat, of exactly the cause of death. Reporter there are no bullet holes, no knife wounds. No blunt force trauma. Reporter you thought she had been strangled. But theres no fingerprints either, right . And theres no marks around her neck. Right. Because of decomp, we dont have the telltale signs of strangulation. Reporter matt leili is definitely a suspect in his wifes murder. In fact, the only suspect. But there is not enough evidence to charge him. Niques family is beside themselves. Her daughter alex almost feels guilty. Like, there was something i wasnt doing to help fight for justice. There was something i was missing. Sometimes you just wanted to scream at the rooftop. You know, he did it. Do something. Reporter matt cuts off niques family. Isolating his daughters, they skip a memorial for nique. They dont even go to her funeral. He stops talking to police too. Police say matt leili is not cooperating, refusing to meet with them. Reporter the case is growing cold. And worse yet the day before what would have been matt and niques 14th anniversary, sidneys cove is being vacated. Today we found two moving trucks in the driveway. Reporter matt leili is moving away from niques accusing family. There is no recourse so we feel very helpless. Reporter and the questioning georgia cops. As far as restricting his movements, we dont have any right or reason to do that right now. Reporter starting a new life 1,000 miles away in a Hilltop House in rural londonderry, vermont. And he is taking amanda and rebecca with him. Well, hes gone away, alex, but the real downside is your sisters have gone away too. It breaks my heart. To be completely honest, it breaks me down. I practically helped raise those girls. Reporter time is moving. But the case is not. Alex, niques oldest daughter, is planning her wedding with no mother of the bride. The other two daughters are now teenagers. Sydneys cove is foreclosed and sold off. A family divided. A case frozen in time but not forgotten. At police headquarters, located poetically on hi hope road, sits Sergeant John richter, unwilling to give up on hope. He spends an entire year listening to what its like being watched and controlled 24 7. Im supposed to live my life running around wondering where a recorder is . What emails are being read . Who brought that on themselves . No, matt. People dont live that way. Reporter 1,200 hours that he says reveal to him, the only crazy thing about nique was that she was married to a monster. [ bleep ]. Lower your voice i am not going to sit here and listen to this [ bleep ]. Reporter matt shows he is just as capable of losing his temper and according to nique using his hands as well as his voice to abuse her. If i wanted to do harm to you i could have done it. You think im going to harm you . I dont know, matt. You tried to tonight. I did not. [ bleep ]. With 65, 250 [ bleep ] plus pounds, with your hands around my throat. You had me pinned to the [ bleep ] wall. All my homicide victims over the year, ive never met anybody. But after listening to these recordings, it gave me the you know, ability to know her. Reporter you liked her. I think she was a wonderful person, a wonderful mother, and by all accounts, she was a wonderful wife. Just couldnt do enough for one individual. Reporter and you became determined to get this solved. I wasnt going to give up. Reporter that devotion leads to a big break. Something as good as a bloody fingerprint hidden deep inside matt leilis computer. This was enough to tip the scales. Reporter control, alt, arrest. Matt lieli, about to find himself in handcuffs. And his teenage daughters, staying loyal to their father. How far will they go to prove daddy didnt do it . Jail house pho announcer 20 20 saturday continues with what the camera didnt see. Seems like over the years, i must have passed this place hundreds of times and i always thought of her. Id always stop and look. Reporter as years passed, some may have figured hell would freeze over before police would solve the strange case of nique leili, found dead near her home in the atlanta suburb of lawrenceville. Its a day much unlike today. Its, you know, not snowing. Its july. And its hot. Reporter it is definitely freezing on this day, more than four years later, as cold case cop john richter leads us to the little woods where her nude body was hastily b