i'm tamron hall. thanks for watching. >> there's this pile of leaves and it's where everything else is flat. my heart is racing a million miles an hour. i was using my boots to move leaves and that's when i screamed this blood curdling scream. >> nikki, a corporate executive who made time for romance and her three daughters. >> she was the best mom.

>> reporter: then she disappeared. dozens joined the search. >> we need nikki to come home. >> reporter: then they found her. >> launching a mystery that would divide this family. >> i suspected him from the beginning. >> reporter: one daughter thought her stepdad matt did it. the others said no way. and matt, he had a theory all his own. >> this is not the first time she's run away. >> reporter: had nikki taken off and found trouble? >> so you're thinking somebody gave her the date rape drug. >> possibly. >> it would indicate a large amount of data being stored. >> what they found was thousands of hours of tape. >> it's absolutely a torture to listen to. >> reporter: and would reveal one shattering truth. >> i got down on my knees and just started crying.

welcome to date line extra. nikki was a mother of three juggling family life and a thriving career when suddenly she vanished. friends and family quickly organized a search team. meanwhile detectives turned to those closest to nikki for information including her husband who had a lot to sigh and an astonishing discovery. nikki's last months had been caught on camera. could the recordings lead detectives to nikki? here's dennis murphy with the house on sydney's cove. >> reporter: there's never a good day to search for a missing woman, but this rainy, muggy saturday in the heat of july made an unhappy task all but unbearable. >> take some flowers with you. >> reporter: they decided, the friends and family that they'd all wear red shirts.

they got themselves organized in the parking lot of a walmart about an hour outside of atlanta. and set out to find any trace of a petite corporate executive named nikki. amy told reporters that her 44-year-old sister, mother of three, was hardly the kind of person who just up and disappeared without a word to anyone. >> i'm so worried about my sister. we have no idea where she is or what's happened to her. the question of where nikki was would be answered soon enough, but even now the question of what happened to nikki remains unclear. >> i'm sick of playing your games. >> what is clear from the recordings she left behind is that nikki lived a troubled and tormented life. >> this is what i live day in and day out is keep my mouth shut, my head down, and do

exactly what's expected of me. >> she was very funny. she and i used to laugh all the time and she was very -- she was very feisty. she -- she would say what she meant. you know, she didn't mince a lot of words. >> reporter: as sisters they were ten years apart but according to amy, they were always close. >> you two look alike in the old photos. >> we do. >> you're ten years apart. >> i wore a lot of her hand me downs. >> reporter: nikki had been married and divorced twice and she and her young daughter alex were sharing an apartment with amy. >> we had a good time. we laughed putting up picture ms. the apartment and stuff. >> reporter: this sounds like a sitcom. >> oh, yeah. >> reporter: eventually nikki moved out and had two more daughters with her third husband, a new yorker she'd met

online. >> we would all laugh. >> reporter: after brief stays in oklahoma and mississippi, nikki and matt returned to georgia and settled into this house on sydney's cove in lawrenceville. nikki was the primary breadwinner. matt, a computer guy, ran a small business out of the house. he started going to government surplus auctions and used these big pallets of old computer parts and would rebuild them and sell them on ebay. >> reporter: when when it was amy's turn to get married in 2003, her big sister was there. >> i just want to raise a toast to amy, my best friend, my sister and to the love of her life who makes her head spin, to amy and dillon. >> reporter: then later that night boogying to "we are

family." >> reporter: in late june 2011 amy organized a spa day out for nikki and her three girls. >> no boys allowed, only -- we're going to have a girl's day. >> reporter: where did you go? >> we went to go get our nails down. >> reporter: day of beauty at the spa. >> we went and got our nails done. >> reporter: nikki had her nails painted pink that day. alex says that day at the spa felt like a turning point, a fresh beginning. >> reporter: everybody looks pretty happy. >> yeah, it was fun. beyond grateful now that we've done it. >> reporter: two weeks later nikki had apparently left home many the middle of the night without a word to anyone. >> their response was we don't even know where to start looking. >> reporter: she's not on the

11:00 news every night. >> no, because frankly a grown woman having left her house wasn't that interesting a story. >> reporter: so then the cameras were out. >> then the cameras came. >> reporter: and this is what the cameras saw. searchers armed with maps literally beating the bushes around nikki's subdivision for clues as to what might have happened to her. >> keep your eyes open if you see her. definitely call 911 and let them know that you've seen her. >> reporter: every searcher had an assignment. nikki's mother had the job of going door to door. even though southern hospitality may have been in short supply, she pressed on. >> good morning, sir.

my daughter's missing. and they're trying to get some news coverage. >> reporter: like so many of the volunteers that day, allison wasn't a relative. she was looking for nikki, her coworker. >> i loved nikki. nikki was great. she was just so great to work with. very smart. lots of energy. just a wonderful person. >> reporter: allison recalls that she and another colleague from work were running late. that would turn out to be an important twist of fate. >> 40 minutes late actually. everyone else had started searching. >> reporter: so were you given a grid or an area to look at? >> yes, we were given the front of the neighborhood. the very front of the neighborhood on the right. a patch of woods near a busy road. >> derek and i went into the

woods together. and i remember having to walk up and go over a large tree. and there's this pile of leaves and it's and it's where everything else is clear and flat and my heart is racing a million miles an hour. i go up to the pile of leaves, i was using my boots to move leaves at the bottom of the -- of the pile. he heard the panic in my voice and he started helping me and that's when we saw blond hair. and i screamed this blood curdling scream. >> reporter: and there was no question. >> no. >> reporter: coming up -- >> she said it's her. we found her. there's her hair. >> reporter: how awful for her. >> a body and a vital clue. >> the telling factor was the bottoms of her feet were clean.

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welcome back. the suburban mom had been missing for a week when friends and family put together a search team. then a heart breaking discovery in the woods not far from nikki's home would turn the area into an active crime scene. here again is dennis murphy with the house on sydney's cove. >> reporter: at first, it was the unnatural way the leaves were clumped that attracted attention. then it was the hair. >> and i hear a scream from the woods. >> reporter: you hear a scream. >> yeah and i tore off running into the woods and when i got into the woods her coworker allison was there and she said oh, my god, it's her. we found her. there's her hair.

>> reporter: how awful for you. >> yeah. >> reporter: nikki's sister amy and her worker allison felt for sure the body beneath the leaves had to be nikki. >> i just kind of went into crisis mode and i called 911. >> reporter: within minutes, police, ambulances and news cameras were converging on the woods where the body was found. nikki's mother said she heard the news when a cop told her she'd have to stop leafletting the neighborhood. >> someone had complained and while he is talking to me his radio goes off. it's a dispatch, body has been found. >> reporter: you hear it over the dispatch. >> yes, sir. yes, sir. >> reporter: do you actually go to that place? >> yes. well i couldn't -- by the time i got there they already had the crime scene tape up and i couldn't get any further.

they had it'slated by that time, but i got to it as close as i could. >> reporter: soon harriet had nikki's oldest daughter alex on the phone. >> you know it's her? i'm right here. the police won't let me come, honey. they won't let me through. i'm right here where the police are. they won't let me through. where are you? >> i just remember fainting or something, but as soon as i came to, i took off running. and i ran all the way to where the crime scene tape was. >> you can't, baby. >> of course they wouldn't let me see her and i'm grateful that they didn't know. >> reporter: as nikki's family struggled to process the news, amy faced the microphones and once again became the family's voice. >> all we saw was her hair. but you know, so we're just waiting for the police to do their job and we'll find out

more soon. >> reporter: inside the police tape, investigators carefully uncovered the body of a middle aged female. she was nude, lying face down and tellingly appeared to have a fresh pink pedicure. given the decompensation, the heat, the rain, investigators figured the body had lain there for a while. >> it had been out there several days. >> reporter: police detective brad everyson. >> no clothing whatsoever. >> reporter: any injuries to the body? lacerations, blunt force trauma, gunshot, stab wound, anything you could see. >> nothing. and of course at this point there's no -- there's nothing around where the body is at that would indicate what happened. >> in the way of these things dental records confirmed what everyone suspected. the body in the woods was nikki. >> the telling factor was the

bottoms of her feet were clean. >> reporter: what does that tell you? >> that tells you she didn't walk out there and put herself in those woods. she sure wasn't going to cover herself up. >> reporter: later, lab analysis of nikki's blood revealed something else that was odd. there was a high level of the date rape glad ghb in her system. >> reporter: so now you're thinking maybe sometime before this woman's death, someone gave her the date rape drug. >> that's a possibility. >> reporter: and they also found semen. >> correct. >> reporter: had she been abducted, raped and dumped less than a mile from her home sm the detective couldn't say. but while this was still a missing person's case, nikki's husband matt had told everson something intriguing on the phone. this wasn't the first time nikki had walked out on him. >> my wife has a long history of some kind of mental imbalances. okay? and i've been finding out the past two days everything she's

been telling me in therapy all these years has been a lie. >> coming up, the nikki no one knew. stories of unstable behavior. >> this is not the first time she's run away. >> and even violence. >> her father is a witness of her throwing a knife at my face. ♪ using 60,000 points from my chase ink card i bought all the framework... wire... and plants needed to give my shop... a face... no one will forget. see what the power of points can do for your business. learn more at chase.com/ink see what the power of points can do for your business. ...doesn't go on your wrist. technology... ♪ the highly advanced audi a4, with class-leading horsepower.

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welcome back to "date line extra." it didn't take long pr the police to discover that the body discovered was nikki. lab tests would reveal something abnormal. she had high levels of a date rape drug in her system. dennis murphy returns with the house on sydney's cove. >> reporter: by the time searchers found nikki's body, police detective brad everson already knew bits and pieces of her life story. he'd been working her case since she was reported missing a few days earlier.

>> i'd already talked to her dad, her mom, both her sisters, talked to her oldest daughter. >> reporter: the picture that emerged was of a woman whose life had revolved around her work, her daughters and her husband matt. >> he would come sometimes and do lunch with nikki. >> reporter: did she ever talk about her girls? >> yeah, she was very proud of all three girls. yes. >> reporter: photos on the desk kind of thing? >> oh, absolutely. >> reporter: like most marriages nikki's had its ups and downs. early july 2011 when nikki disappeared was one of the down times. matt freely admitted that. >> she's run away and she's been gone for two hours, she's been gone for three hours, four hours one time. she's gone to work with a bag of clothes and then come back after work, you know, but she's never been gone overnight. >> reporter: so he's telling you this is the latest of a

continuing episode that my wife has. >> correct. >> reporter: many this telephone call which the detective recorded matt said his wife was mentally unbalanced. >> she's not very happy with her life. she never felt accepted. okay? we've been in and out of therapists. there's a fear of intimacy. she's got no problem with girls but when it comes to a male they're a threat. they are -- all my life guys have used me for sex. >> reporter: he's giving you a hose full of information? >> i have ha hard time getting a word in edge wise. >> all i'm doing is please stop. do you remember what the doctor said? is this the the person you want to be. >> reporter: he even said he considered getting a court order. >> i've got pictures of myself with bruises on me. my father was a witness for her throwing a knife at my face. i'm 250 pounds.

she's 100 pounds soaking wet. >> reporter: he's telling you that she's bats? >> absolutely. he stated they had gone out to eat and gone to a movie after she'd got home from work. >> we had a great time. we came home, on the way home i said to her, you know, hey, you know, i wanted sex so i said to her, you know, how about you put on an outfit? i think that might have set her off. >> reporter: she wanthe wanted put on a sexy costume. >> correct. >> apparently that set her off because she picked a fight. >> reporter: as matt tells it, the fight continued at home and ramped up. matt's father who was visiting from new york was just down the hall. when the argument touched on the way nikki had supposedly been treating her father-in-law, matt asked his dad to weigh in. >> he called his father into the bedroom and basically asked him

to tell nikki how he felt about being down there and that he came out with a line that he hn hadn't felt welcome and nikki reacted by saying he was lying. >> reporter: then matt said his wife did something off the wrong. >> i mean, she rips her shirt off with her [ bleep ] hanging out, no bra or nothing and she says maybe we should just [ bleep ]. throws her shirt on the floor and said isn't that what family does. >> reporter: she flashed her father-in-law. >> my wife has done some weird [ bleep ]. that's the weirdest she's ever been. >> reporter: nikki in the bedroom, he on his couch many the downstairs office. >> i wake up about 6:00 to go to the bathroom. the light is on in the bedroom. i can see it upstairs. so i go upstairs to see what's going on. she's not there. >> all her stuff was still

there. her car was there, her keys, her phone. >> reporter: her purse was still there. >> correct. he assumed she left on foot. >> reporter: it was then that he realized his home security system had been turned off. >> i have a camera system in the house because i sell cameras with a dvr. she always shuts it off when she leaves. >> reporter: that's the first you learn that this place is wired for sound and pictures. >> correct. >> reporter: when her body was found days later near her home, learning the story told by those cameras became most urgent. >> coming up, a treasure trove of evidence. >> reporter: quantify it. what are we talking about? >> thousands of dollars of material. >> just what will it reveal? it's absolutely a torture to listen to. ♪ the highly advanced audi a4, with available virtual cockpit.

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announced the start of an offensive to retake mosul. isis has been in control of that city since 2014. donald trump is making it clear who he blames for an attack on a republican party office in north carolina tweeting out animals representing hillary clinton and dems in north carolina just fire bombed our office in north carolina because we are winning. the clinton campaign and the north carolina democratic party have condemned that attack. for now, back to dateline extra. >> welcome back. nikki was dead and now her husband was telling police that this seemingly happy mom had a dark side. he claimed nikki was violent and mentally unstable, especially on the night she disappeared. they were about to get a better view into the home than they could have ever imagined. here again is dennis murphy with

the house on sydney's cove. >> reporter: within minutes of finding her body, police raced to the home about a mile away. what they observed right away was astounding. the home security system that mad had casually mentioned a few days earlier, appeared more appropriate to fort nox than a house in the burbs. >> you can see all these huge, these big cameras on the eaves of the house. both sides. >> reporter: 21 security cameras in all with a tricked out control room to monitor and record everything. >> he sounds like a one man nsa. >> a very low crime area. so you know, it almost boggled the mind as to why he felt he needed quite so much surveillance coverage for the house. >> reporter: an observation to tuck away for later but the duty became first notification. the officers telling him that his missing wife had just been

found dead. >> the uniformed guys told me that he at one point seemed like he got sick. >> reporter: he may well have been sick. sick of talking to the cops because by now he's lawyered up and wasn't answering any of their questions. so you now have probable cause to get a search warrant. >> correct. >> reporter: do you think this is going to help us? maybe these cameras saw and recorded something that tells the story. >> that was my hope. we're mainly going for anything in the house that has any sort of memory, be it computers, be it, you know, he had a dvr hooked up to his system. >> reporter: the detective knew it would take time to review and catalog all of that material. is since the police had found no sign of blood or any signs of struggle in the house the detective reviewed the evidence he did have, particularly matt's claim that his wife was bankers. >> are new of her family members

corroborating this emotional instability claimed by her husband. >> none whatsoever. >> reporter: are any of them suspicious of matt, the husband. >> yes, they were all suspicious of matt. >> reporter: there was plenty her daughter had to say to the detective. >> i wanted him to know what was going on many the house. i wanted him to know that i suspected him from the beginning, that my mom would have never left her girls, and i wanted him to know he would restrain her and lock her in bathrooms. >> reporter: why did he do the whole thing with the cameras? >> she's just extremely controlling. >> reporter: despite the family's suspicion and the semen on her body proved to be matt's they didn't feel they had enough to make an arrest. you haven't taken his passport. does anybody say if you're going to be moving around tell us where you're going to be?

is it that kind of relationship at that point. >> no. there's not really a relationship with us. >> reporter: what about all the video evidence? they appeared to be use legislation. aft ---less. the best investigators could come up with was this. it's a film of nikki walking up to have a smoke. the day she went missing. after that, nothing. >> reporter: whav what happened after nid might in that house? >> that was the million dollar question. >> reporter: the video files from midnight until 6:00 in the morning that day were corrupted according to the tech guy who examined them. >> you could see footage but it was very disjointed. most of it was not time stamped or date stamped so it was not in a manner that you could go in and click play and play through everything. >> reporter: the bottom line, the police had zero, nada,

zilch. and so with no compelling reason mad moved back up to vermont to be closer to his family. that was in february, 2012, almost 7 months to the day after nikki's body was found. nikki's stepmother said that move effectively ended all contact between nikki's family and her two youngest daughters amanda 12 and rebecca 9. >> he was to provide us with telephone number. he was to set up a skype account so we could talk with the girls. nothing. packed up and moved. >> reporter: five months later in the summer of 2012 the investigative file passed to cold case detective. >> i was actually in the homicide unit as a corporal when her body was found. >> reporter: does that stay with you? >> yeah, i always say there's certain cases that stick with you and this is one. >> reporter: at first he did what all cold case detectives do. he reinterviewed witnesses. when that went nowhere, he took another look at matt's computer

hard drives. >> reporter: do you think somewhere in there is the nugget that's going to get you to the next step in this investigation? >> i think we need to redo it just to see if technology had advanced. so i needed a new guy to look at the video or whatever else he could find on the computer. >> reporter: turned out the tech he needed was just down the hall. he had been an it guy before joining the police force. >> he came down and said hey, do you mind taking a look at this? so i start looking at what's easily available. and i really started digging through and finding all these audio files. >> reporter: nobody had listened to the audio files before because investigators were so focused on looking for video. >> i basically looked at that video in raw format which is basically computer language. >> reporter: so something was recorded there. >> yes, they just wouldn't play. >> reporter: he determined the screwed up files were no

accident. someone had deleted those files and run a cleanup program to clear the database logs. not once, was twice. >> the only days was the day he reported her missing and the day her body was found. >> he turns to leave and i think he just looks back and he says oh, i got a bunch of audio files on there if you're interested. >> reporter: quantify it. what are we talking about in terms of hours of material? >> thousands of hours of material from 2008 up to 2011. >> reporter: the audio recordings are probably best described as cringe worthy scenes of a very bad marriage. >> that's not how i said and how i said it. when we got in that [ bleep ] car [ bleep ] [ bleep ]. damn it. control your voice. >> what's actually a torture to listen to because we have a woman who i know is now deceased and i'm hearing how she's living

for the years preceding her death and how she's just being beaten down psychologically and mentally. >> reporter: it took the detective nearly a year and a half to listen to all of the recordings. and by then, he'd heard more than enough. when he learned that matt would be returning to georgia to testify in a civil suit concerning the payout from some life insurance policies nikki had, he planned to be waiting. >> coming up, would investigators have it all wrong? nik nikki's youngest daughters paint a picture of her mother's inner battles. >> she would hear voices. >> and why they are furious with her mom's side of the family. when "dateline extra" continues. i have to tell you something. dad, one second i was driving and then the next... they just didn't stop and then... i'm really sorry. i wrecked the subaru.

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welcome back. for years matt had been recording almost everything that went on inside his home with security cameras. the video from the short period surrounding his wife's disappearance was gone. cold case investigators believe it had been deleted intentionally. and they wanted to ask matt some questions and they were about to get their chance. back to dennis murphy with the house on sydney's cove. >> reporter: in march 2015, matt returned to georgia for the first time since he'd left the state three years earlier. it was money that brought him back. a court proceeding concerning a payout from his wife's life insurance policies. >> i knew he was coming down. it made me feel really creeped out. >> reporter: this was three years later? >> uh-huh. what we didn't know is that the whole courthouse was crawling with police. >> reporter: they were taking

him down that day. >> they were. we had no idea. >> reporter: the plain clothes cops waited all day for just the right moment to make the move. how does it go down? >> we put the handcuffs on him, it felt pretty good. >> reporter: nikki's family knew the feeling. >> i raised my hands and said praise god. that was my reaction. >> reporter: in addition to facing a murder charge, matt was eventually charged with sexual assault and multiple counts of eaves dropping. a few weeks after his arrest nikki's daughters amanda and rebecca posted an edited video on youtube in support of their dad. in the video the girls claimed that their mother hated their own family and those same spiteful relatives were the primary reason their dad was in jail. for nikki's family, that video was devastating. what they wondered had happened to those girls in the four years they'd been in vermont.

>> he poisoned them against us and i can only attribute that to, you know, them living in a house with a master manipulator. >> reporter: the notion of matt as a master manipulator would become a central theme when his murder trial began in january 2016. >> good morning ladies and gentlemen. >> reporter: prosecutor depresident-electdepicted matt as a couch potato. >> she was the breadwinner. that family was in debt up to $300,000 in debt. >> reporter: further more, she said, matt tried to control his wife by turning their home into a virtual north korea with cameras and recording devices everywhere. lenses aimed at them as they sat on the couch and watched tv. >> you will take a look into this marriage, ladies and gentlemen, in this case. you will hear the voices of nikki and the defendant in this

case arguing. >> reporter: nikki's murder she claimed was simply matt's final act of control. >> i think they got into an argument, that he wanted to have sex. that he drugs her. that she's not able to resist as much as it progresses that sesilences, he asphyxiates her where she can't breathe. >> reporter: not meaning to maybe. >> i think he meant to. i think she knew that she was leaving him. she made it clear she was done. >> reporter: the state's first witness was nikki's oldest daughter alex. >> he would end up locking her in a bathroom. she'd been shoved downstairs, there were several nights that i would lay up at night and listen to her say please get off of me, get off of me, you're hurting me. >> reporter: next nikki's sister amy told the jury about the constant monitoring at the house. >> we knew he would record phone

conversations that came into or out of the house. >> were you aware at any time whether there were gps trackers or tracking devices on the phones or the vehicles of the residence? >> yes, i knew that he had trackers on nikki's phone and when alex was old enough to have a cell phone that he tracked her phone as well. >> reporter: then the prosecution gave the court a fly on the wall look inside the home by playing those promised recordings of the couple's fights. >> let the record show i am now locked in a room again. i don't want to be here. i don't want to have this conversation. i've asked out of it. >> the record shows she's being an absolute [ bleep ]. wants her way no matter what. >> reporter: it was hard to listen to. bitter screaming matches frequently about sex. >> i know that when we go two days without sex you're going to automatically assume i am on strike mode no matter what else is happening. don't touch me. sit down if you want to sit down. >> i'm reaching out to you.

>> i don't want to hold your hand right now. >> reporter: in retrospect the recording seemed to have the ring of prophesy. >> your hands are around my throat. >> my hands are not around your throat. >> [ bleep ]. you threatened to kill me. >> reporter: the prosecutor said nikki's best chance for leaving her marriage came 12 days before she disappeared. after yet another argument, nikki had called 911. >> yes, my husband won't let me leave the house. >> my wife is yelling and screaming and just woke up the children. >> reporter: officers dispatched to the home that day offered to help nikki leave, but as the still photo shows she wouldn't budge from the front porch. >> he didn't want to go. he wanted her to go. she wasn't going to leave without the girls. so the argument was pretty much at an 'em pass.

very then she was dead. in a house where practically everything was recorded the prosecutor claimed it was no accident that the video covering the crucial hours when nikki went missing was somehow corrupted. >> the surveillance system was in fact recording during that time period. is that correct. >> that is correct, yes. >> reporter: the prosecutor countered the claim that nikki had somehow turned off the security system by calling the police department's it tech. >> so did an individual have to go in and purposefully corrupt and delete those files. >> that's correct, yes. that's the only way i can explain why all of the dates and videos i can recover, that's the only days i can't recover from. >> reporter: the prosecutor suggested that it was probably video of matt carrying his wife's body out of the house. >> you heard her. >> reporter: in closing the

prosecutor let nikki have the last word. >> you need to listen to what she says and what she lived. >> welcome to my world. you killed me a long time ago. >> welcome to my world. you killed me a long time ago. find him guilty. because that's exactly what he is. >> coming up, as the prosecution really proved anything? >> i think their gut feeling was she was buried this close to the house, it's got to be him. >> it's what you call a circumstantial case. >> and then the daughters say in their parents' marriage matt was the victim. >> she took a heel and threw it and i myself had to duck from it. >> was it being thrown at your head? >> yes. >> when "dateline extra" continues. ♪ using 60,000 points from my chase ink card

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welcome back. here's dennis murphy with the

conclusion of the house on sydney's cove. >> reporter: by early february 2016, the prosecution had rested its case against matt. the husband was portrayed as an eaves dropping control freak who'd killed his wife during an argument. his defense attorney insisted that matt was in fact, an innocent man falsely accused by the state of georgia. >> they have a theory and that theory is nothing more than a hunch. it is a guess. so if you were to ask yourself questions that might have been posed of you, if you were to have gone to journalism school, who, what, where, why, and how, you will find that during the course of this trial, the state of georgia will fall woefully short in proving the allegations that they are making against this man. >> i think their gut feeling was come on, she's naked, she's

buried this close to the house, she's obviously hidden, it's got to have been him. >> reporter: it's what you call a circumstantial case. >> yes. >> reporter: he had some circumstances to overcome beginning with the six hours of missing surveillance camera video from the night she disappeared. >> the video surveillance system was shut off at some point in the morning. matt believes that nikki shut it off. he is insistent that he didn't shut it off. >> reporter: so whatever happened to her, the cameras didn't see it. >> the cameras did not see it. that is correct. >> reporter: as for the audio recordings of the arguments, he pointed out that most of them were recorded in 2008 and 2009, two years before nikki died. according to the defense attorney matt made the recordings with the encouragement of a marriage therapist that the couple had been seeing at the time. >> he is talking and he is

conciliatory in my opinion. he is trying to calm things down and it is impossible to calm nikki down. >> please, don't do this. please. >> you do not want to do this with me right now. i mean it. you do not want to tangle with me right now at all. >> what did i do? >> according to his attorney the prosecution cherry picked scenes from the marriage highlighting the bad and downplaying the good. bright spots like a 2010 trip they took to hawaii. they even renewed their marriage vows. >> the tapes reflect both of them at their worst. the flip side is when they're getting along well, when they are affectionate towards one another, when they renew their wedding vows in hawaii, they don't tape that stuff. >> reporter: the darkest side of the moon. >> the darkest side, yes. >> reporter: as for the night she disappeared. the defense tried to show she

was behaving erratically. the father-in-law was called to verify the allegation where she allegedly flashed him. >> she tore off her top and said let's go, let's f like a family. >> were you expecting any sort of comment like this? >> never. never. >> reporter: once nikki disappeared, his attorney says he inquired about having his wife involuntarily committed. a man who knows his wife is already dead, he says, wouldn't have done either of those things. >> he did not want to divorce her. he wanted to let her know, look here are your options. you can get help if yourself or i'm going to go forward with a divorce. >> reporter: the defense wrapped up its case by calling matt and nikki's two daughters.

rebecca 14 and amanda 17. >> did you ever see your dad hit your mom? >> no. >> did you ever see any obvious injuries or bruises to your mom? >> no, sir. >> reporter: according to the girls their mother was the one with the violent temper, not their dad. >> she took a heel and threw it and i myself had to duck from it. >> was it being thrown at your dad. >> yes. >> reporter: amanda said her mother complained about hearing voices in her head. >> she was pacing back and forth saying that she was tired of people talking bad about her behind her back and my dad asked her who was talking about her and she said that she was hearing voices and like the voices in her head were telling her that people were talking bad about her. >> reporter: throughout, neither girl made eye contact with their mother's relatives who hadn't seen them in four years. whatever affection might once

have existed seemed to be gone now. >> we made our own decision, we don't like that side of the family so we wanted to stay away. it's not him forcing us to stay away from them. >> reporter: he argued that while the state may have proved matt unlikable it had not answer any of those basic journalism questions. who, what, where, when, why or how? >> i said you've heard all of this evidence. the state cannot answer any of these particular questions. what does that tell you? that tells you they have fallen woefully short of proving matt's guilt. >> reporter: after eight days of testimony, both sides of the family prepared for a long and anxious wait for a verdict. turns out they didn't have to pace long. after just three hours of deliberation the jury announced it had reached a verdict. >> i'm going to ask at this time if you would stand and read the verdict out loud. >> as to count one we the jury find the defendant guilty of murder. >> reporter: though not a sound

came from nikki's family, their expression said it all. >> thank you, sir. >> reporter: before passing sentence the judge gave matt one last chance to have his say. >> is there anything you want to say? >> i didn't do it. and i'll be filing an appeal. >> reporter: with that the judge asked matt to rise and receive his sentence. >> i am going to follow the state's recommendation to count one and have you sentenced to life without the possibility of parole. >> reporter: it was a bittersweet ending for nikki's family. they'll likely never see matt again but as nikki's youngest girls left the courthouse to go back north, it seemed just as likely that they would never see them again either. >> they were my girls. i still love them to this day. i taught them how to read, got them ready for school in the mornings. >> reporter: you'd live like to have a relationship with them? >> i'd love to. i don't know that that day will ever come but i want them to know my door is always open but

i don't know if that day will ever come. >> reporter: one murder, so many victims. >> that's all for this edition of "dateline extra." thanks for watching. when i saw her, i lost concept of time. i reached in, pulled her out, i started screaming help. >> please! emily, wake up! wake up! >> it was the worst seconds of my life. >> how was it possible? >> i would give anything if