loudly, and now. and if you hear someone else, speak up. don't let a cry for help go by. >> i'm craig melvin. >> i'm natalie morales. and this is "dateline." you had the good cop. you had the bad cop, and the polygraph. it felt like "law & order." >> the fire broke out before dawn. in the daylight they found this mother of two young children dead. >> she lived a very courageous life. she was very bold in the things she did. >> but after the smoke cleared a mystery lingered. >> we knew she did not die in that fire, she died before the fire. >> who do you look to as the suspect? >> obviously the spouse is the first person you look to. >> but her husband had a clear alibi, and he passed a lie detector test.

eventually, the case grew cold. until this witness came forward with a tale of love and lust gone wrong. >> he took the sweatshirt and wrapped it around her neck. >> but could she be believed? >> i was sleeping around. i think i slept with half the town. >> was she out for justice or revenge? >> is it a perfect world? no. will she get hers? yes. when she dies. >> what was the lie, and what was the truth? >> how could you miss it? he wasn't there! hello. and welcome to "dateline." paul and kathryn novak wanted to escape the hustle and bustle of the big city. they found peace and quiet when they moved into what kathryn dubbed the big red house. but soon a roaring fire would ravage the couple's home.

and when the flames subsided, one of them would be dead leaving investigators wondering if the blaze was a tragic accident or something more sinister. here's andrea canning with "secrets & lies." >> reporter: on a frigid december morning in 2008, in a tiny picturesque town along the banks of the delaware, a tragedy unfolded. >> 911. what is your emergency? >> the whole house is on fire. >> reporter: a deadly blaze burned a small country house to the ground, and left behind in the ashes were secrets. love gone wrong, illicit affairs, friends turning against each other. it would take years to unravel the mystery of that fire, haunting this town. and those who loved the couple who once lived in that house, paul and catherine novak. the novaks had both grown up as city kids. paul was a new york city paramedic, a job that seemed the

perfect fit. >> i wanted to be that person that would show up that would help my parents, help my sister if she was in a car accident or something like that. >> reporter: but he also saw the dark side of city life. a little too close to home. >> i would do shootings and stabbings two blocks away from my apartment, and i always thought to myself that i could just never raise a child in this area. >> reporter: so in 2002 paul and his wife, catherine, went house hunting in narrowsburg, new york, a small hamlet tucked between the catskill and pocono mountains. they didn't need to look for long. >> it was the big red house as she called it. and she would talk about the big red house all the time. >> reporter: catherine's brother michael and sister-in-law joanne said she worked hard to make the big red house a home. >> growing up, we lived in apartments. you know, this was a space of her own. >> yeah, she was thrilled to have five acres or ten acres of property, and she loved it there. >> reporter: the perfect place for the perfectly matched couple. they seemed meant for each other right from the start.

>> i liked her from the first moment i met her. she was very effervescent and very funny and very opinionated, and i really liked that in her. >> so you really saw into the future the first time you saw her. >> yes. i mean, we ended up getting married i think seven months later. >> reporter: two years after that their first child, natalie, was born. >> it was very special. >> reporter: catherine's mom, christina, was ever the proud grandmother. >> natalie looks so much like her mom. so much like her mom. >> what was it like the first time you laid eyes on your new daughter? >> natalie. it was like falling in love like a thousand times more than you have with any other person. natalie's just -- you know, she's a part of me. >> reporter: four years later along came nicholas. >> she was in her glory. and then you know, to have a boy and a girl, which was good. >> things were all coming together. >> yep. >> she got directly engaged in the community, in the church. she taught sunday school.

she became a girl scout leader. the school board. she did many, many things. >> and she did almost all of it by herself. paul was still working as a paramedic in new york city, more than 100 miles away. >> that's a big commitment. this is pretty far from the city. >> it's a two-hour drive. i was making the new york city money but living up here. and the sacrifice was that i couldn't be home every night. >> and that, they soon discovered, can be tough on a marriage. >> we went to counseling for about year. and she just felt that she never got a break, you know, from being a full-time mom. >> reporter: but they were both committed to making their marriage work. on their tenth wedding anniversary, valentine's day, paul surprised catherine with a ceremony to renew their vows. >> now, i'm not a churchgoing type. so for me to do that is a big thing. i planned a little, you know, couple of day getaway, and she was really taken by surprise by that. and things were good for a couple of months after that. >> reporter: it wasn't enough.

the glow of that getaway faded, and life became routine again. soon paul's eyes wandered to a much younger woman, someone from work. they had an affair, and paul moved out, leaving catherine and the kids alone in the house. >> she was beside herself. she was absolutely hysterical. >> reporter: catherine's good friend and neighbor, sue muller, remembered when the marriage ended. >> she couldn't even get her breath, she was sobbing so hard. >> reporter: but catherine's family, who considered her the eternal optimist, watched her move on with her life, pouring all her love and attention into her children. >> she was very focused on them. very engaged in their lives. did everything with them. >> sounds like that's what was important in her life anyway. >> absolutely. >> reporter: she was working at her children's school and had even been on a few dates. catherine was creating a life without paul. then in december 2008, sometime in the early morning hours, somewhere in her house, a fire

started. >> the house is totally on fire. it's on fire. >> reporter: when firefighters arrived, the big red house was a wall of flames. they had no idea if anyone was still inside. >> does anyone live there? >> yes, yes, there are kids. >> do you know if they're out of the house? >> i don't know. >> reporter: neighbors knew paul wasn't there. he was living in an apartment three hours away with his new girlfriend. that morning he got a call from catherine's pastor. >> picked it up and it was pastor phyllis and she goes, "where are the kids? where are the kids?" and i'm like they're with me. what's going on? she goes, "the house is on fire." >> reporter: firefighters worked for hours dousing the flames. when catherine's friend sue muller arrived, the fire was still raging. she stood vigil for hours, waiting to hear news of her friend. >> all of the sudden the firemen were all concentrated in one area, looking down into the basement, and then the local funeral home was there with the body bag. and i saw them bring the body bag down into the basement.

>> reporter: in the destruction and muck of the basement, under massive pieces of what had been the house, firefighters found the remains of the family dog. and to their horror, the body of 41-year-old catherine novak. >> oh, no. oh, no. it can't be. and i think it takes awhile to grasp that death is forever. >> what did you think when you heard that news? >> i was just a blank. a complete blank. what on earth am i going to tell these children? how am i going to tell them? she was a great mom. i didn't know how i was going to be able to even try to fill that void. >> reporter: the autopsy report said she was killed when heavy debris fell on her. catherine's death was officially ruled accidental. >> she lived a very courageous life. she knew what she wanted. she went after it. she was very bold in the things she did.

>> reporter: a tragic end to a life that held so much promise. but as you've probably guessed, the story didn't end there. for investigators it was just the beginning. not everyone believed this was an accident. >> if it wasn't an accident, was it murder? it certainly didn't look that way, until a second autopsy report came back. coming up -- >> we knew she did not die in the fire. she died before the fire. >> when "dateline" continues. nus ♪

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the remains of that old country house were still smoldering as investigators dug through the debris looking for clues. they wanted to know what caused the fire and exactly how catherine novak died there. her mother's question was more simple. >> the big thing for me was why didn't she get out? that was what kept going over in my mind. why didn't she get out? >> reporter: even her estranged husband paul said he was puzzled. >> i didn't know what to think about it. i'd been surrounded by death and violence my entire life, and now it hits home. >> reporter: the pathologist ruled catherine's death an accident, but investigators weren't so sure. they turned to district attorney steve lungen to take a closer look. >> so you were contacted despite this talk it was an accident.

>> yes. we had a fire and we had a death. the question of how the two of those items were going to come together would not play out for a couple days later and actually years later. >> reporter: the police, as they often do, began by interviewing catherine's soon to be ex-husband paul novak. >> what happened in the interview as far as the way they treated you, the questions -- >> they were nice. they asked about catherine's last known whereabouts, if she had any boyfriends, who may have been in the house, any utilities in the house that may have had a problem, anything like that. >> reporter: the interview was all very routine but the investigation at the scene was not. fire inspectors couldn't figure out what ignited the blaze. they checked the wiring, the appliances, the pellet stove, the propane tanks. nothing conclusive. but then things changed. the d.a. brought in a specialist, a forensic

pathologist, to do a second autopsy a few days later. and the results this time told a different story. >> we knew she did not die in that fire. she died before the fire. >> reporter: the second pathologist discovered there was no carbon monoxide in catherine's blood or soot in her lungs, which meant catherine had stopped breathing before the fire started. she changed the manner of death from accidental to pending investigation. >> the question is what else can we gain or learn before we can start to classify this as a homicide? >> who do you look to as the suspect? >> the state police had done some initial interviews. obviously, the spouse is the first person you look to. the spouse had a clear alibi. >> reporter: paul and his new girlfriend, michelle la france, said they were far from catherine's beloved red house when the fire broke out. a three-hour drive away in their apartment on long island. still, investigators didn't just take the couple's word for it.

they made a request. >> he goes, we want you to take a polygraph test. >> did you feel like you were almost in a tv show at this point? >> yes. it felt like "law & order," a really bad episode of it. >> when did you get the results? >> he came back about 15 minutes later and he said, okay, you're all done, you passed. >> he was driving home from the interrogation, and he was hysterical. >> reporter: paul's sister, ilona, had never heard him so emotional. >> he was crying and saying they asked me if i killed her. he just found it so unbelievable that he was being asked these questions. >> reporter: so if it wasn't paul, investigators needed to look for other suspects. >> the state police did a complete canvass of the area, anybody who had any connection to catherine novak, the state police reviewed, found, interviewed. >> reporter: but after many months and no leads, investigators hit a dead end. the case turned cold. none of that mattered much to catherine's mom.

>> i still miss my daughter the same. i miss her, no matter what happened to her. i miss her. >> reporter: seven months after catherine's death paul and his girlfriend packed up the kids and their apartment on long island and moved 1,000 miles south to florida. >> i figured with my experience that it would probably be pretty easy for me to get a job somewhere. >> kind of a fresh start? >> a fresh start. i thought it would be good for the kids. great school, nice neighborhood. >> reporter: but paul said not long after their move things with michelle started to sour. when they first met, she was a paramedic in training. he was her teacher, her friend. she had confided in him about her history of mental illness, long bouts of depression and alcohol abuse. but now he says her problems were beginning to take a toll on their relationship. his young daughter, a sore spot. >> she was very jealous of natalie. and her mental issues definitely became more apparent as time went on.

at one point she actually threatened to commit suicide inside my own house. >> reporter: this was no surprise to ilona and her mom, who loved catherine but never approved of michelle. >> what are your first impressions of michelle? >> i didn't like her. >> why? >> she walked into my mother's house and she immediately wanted catherine's pictures turned around because she felt like catherine was looking at her. >> reporter: paul said it took him a bit longer than his family to realize he and michelle were not the best match. they had been together for three years when he found out she was cheating on him with a married man. >> he didn't want to stand for that. so he had to ask her to leave. and he did it very nicely. and she didn't want to go. >> reporter: in what paul described as a bitter break-up, he forced michelle to move out and told her it was over. by that time it had been more than two years since catherine's death. investigators back in new york

had moved on to other cases. the years were ticking by with no new leads. but the d.a. was a patient man. >> we never put the file away. it was always a matter of when something is going to come forward, we'll be ready to go forward. we never accepted an accidental cause of death, ever. >> reporter: his patience would be rewarded. a break in this cold case was coming, and it would surprise everyone. >> coming up -- a surprise knock at paul novak's door. >> there's two police detectives outside and want to talk about your car being involved in a hit and run. >> is that what they really wanted? when "dateline" continues. ntinu.

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years had passed since catherine novak's body had been discovered among the blackened ruins of her big red house. but the passage of time didn't make it any easier for her mother. >> it's the thing that never happens to you, it always happens to someone else. it doesn't happen to you. you don't lose a child like that, in such a horrible way, a fire. >> reporter: catherine's brother michael and his wife, joanne, had stopped asking questions, choosing instead to accept they might never really know what happened to her. >> to take catherine's

perspective, she would look for the positive side, the good things, and she would want us to move on. and you know, that's what we tried to do. we made our peace with it, and we went on living. >> reporter: but as time went by in the little town of narrowsburg, dark suspicions were whispered from neighbor to neighbor, and one name kept coming up. catherine's estranged husband, paul novak. her close friend, sue muller. >> i was angry as time went on, and i thought more and more about it and i thought that paul might somehow be involved. >> reporter: as she looked back, she was particularly haunted by the way paul acted the day of catherine's memorial service. >> the whole congregation were sobbing so loud. i mean, the pastor couldn't even finish her sermon. and i went up to him, and i hugged him. i kind of was struck by how he really showed no emotion. after 11 years of marriage that she might have meant a little bit more to him, that he might

shed a tear. but i didn't see any. >> reporter: but there was no evidence that paul had anything to do with catherine's death. no dna or fingerprints at the crime scene. no witnesses. he had even passed a polygraph test. and he had an alibi for the morning of the fire. he was three hours away with his girlfriend, michelle, in their apartment on long island. paul continued to enjoy his new life in florida with his two children. working again as a paramedic and now dating a new woman he'd fallen for quickly on match.com, kat del grasso. >> we started texting and then we made a date, and we went on a date. really that was it. >> it was instant? >> instant. instant. >> what was the attraction? >> i don't know. it's really hard to put your finger on something like that. we just seemed to have an immediate connection. there was zero stress talking. no uncomfortableness.

>> reporter: their romance blossomed, and she eventually moved in with paul and his kids. >> do they look up to him? >> they worship him. they completely worship him. he's always up with them, checking homework. we do a lot of things as a family. >> is it a nice life? >> mm-hmm. we were really happy. really, really happy. >> and then you get a knock at the door. >> yep. yeah. that was a tough day. >> reporter: it was an early morning in september 2012. four years after catherine's death. >> i was asleep. i just got off of work. i worked 12 hours at the hospital. and i remember my girlfriend comes in and she goes, there's something fishy going on outside. there's two police detectives outside and they want to talk to you about your car being involved in a hit and run. >> reporter: but when he arrived at the police station he saw a familiar face and realized this had nothing to do with a car accident. >> this is investigator kelly from new york. so i'm like, okay. so he sits down, he grabs a chair and he's like a foot away

from me. and then i remember him. he's the guy that grilled me, the one that got in my face. >> how are you feeling? oh, my gosh. these people are back in my life, four years later. >> at that point i still didn't know what they wanted from me. i knew this guy was yelling at me and then i just looked at him and i said, "i would like to speak to a lawyer." >> reporter: paul had already been interviewed by police several times. he thought this was all behind him. >> you knew it had to be about catherine. >> well, yeah, obviously it had to do something with that. >> reporter: later that day the police went back to paul's house. >> and i went outside in the driveway with them, and they said, "we're sorry to have to break this to you, but paul novak's under arrest." and i said, "for what?" and they said, "it's for involvement in his wife's murder four years ago." >> reporter: what cat and paul didn't know was that a witness had come forward telling police an evil tale. and in that story paul was the villain. >> they arrested you --

>> right there. >> did they put you in jail right there then? >> yes. >> reporter: the story the witness told was chilling. >> please have a seat there. >> reporter: revealing dark secrets. but was it true? >> coming up -- paul's alibi becomes his accuser. >> he was going to chloroform her, leave her and burn the house down around her and she was going to die in the fire. lowe's knows you'll do it right, to save big on the floors you want. we do it right too, with exclusive options that are waterproof and easy to install.

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i'm dara brown with the top stories. another busy week ahead in the house impeachment inquiry. the highlight expected to be testimony from former u.s. ambassador to ukraine, marie yuvanovitch who was removed from her post. the president calling her bad news in one call. a key witness in the murder of a white dallas police officer convicted of killing her black neighbor has been shot and killed himself. joshua brown was found with multiple gunshot wounds. police are investigating. now, back to "dateline."

welcome back to "dateline." i'm craig melvin. after the mysterious death of his wife catherine, paul novak was trying to move on. he relocated to florida and had a new girlfriend. but then came that knock on the door and detectives placed paul under arrest. soon, he would learn that someone was claiming they had disturbing new details about the night of the fire. paul's world was about to turn upside down. once again, here's andrea canning with "secrets & lies." >> reporter: catherine novak's death had been a cold case for more than three years when, out of nowhere, a witness came forward, pointing a finger at catherine's estranged husband, paul. so who was this mystery witness? a woman from paul's past. his ex-girlfriend, michelle.

>> michelle la france, who was the defendant's alibi in 2008, has now come forward and said paul was not home and that paul went to narrowsburg and that paul killed catherine. >> what was that phone call like? >> it was now time to get to work. >> reporter: jim farrell was now the district attorney. he teamed up with the former d.a., steve lungen. >> didn't it feel good you had a break? >> it's a break. but again, i needed more information. >> reporter: investigators sat la france down to hear her story. >> let's start back in the beginning. >> okay. >> reporter: during a six-hour interview, michelle laid out what she claimed was the true story of how paul killed catherine. she said he started plotting weeks before the murder. >> he was researching things on the internet. he was going to chloroform her and leave her and then burn the house down around her and she was going to die in the fire. >> reporter: michelle says one week before the fire she and

paul went to catherine's house to move his things out and paul unlocked the basement doors. >> so that he can go up the next time we had the kids, which would be a week later, and that way he can sneak into the house and she wouldn't know. >> reporter: according to michelle, paul wasn't with her on the night of the murder. that alibi was a lie. instead, she said he was with a fellow paramedic named scott sherwood, who drove paul to narrowsburg. >> as far as i know, scott was left in the car, and paul walked down to the house. >> reporter: michelle said paul told her he went inside, set off the basement smoke alarm, hid behind the stairs, and when catherine came down to investigate he tried to knock her out with chloroform. >> this was supposed to be quick and painless and, you know, she was supposed to be passed out before she knew what happened. but i guess he put it over her mouth and it didn't work. she was screaming and begging him for her life.

>> reporter: through her tears michelle spilled out gruesome details of what paul said were catherine's final words. she begged him to think of their children. >> and he told me that the only thing he said to her the entire time that he was fighting with her was, "i'm doing this for the kids." and he said that she had been wearing a hooded sweatshirt and that he finally just took the sweatshirt and wrapped it around her neck and held it until she stopped breathing. >> reporter: then michelle claims paul took a blow torch from the garage and set the kitchen curtains on fire. >> he waited for it to catch fire. and i don't think he ever told me how long he -- i don't think he ever told me exactly how long he sat there and waited and watched. >> reporter: michelle's story was a stunning betrayal of her former boyfriend and if it was true, paul had committed a vicious and calculated crime. michelle said paul told her he did it because catherine was a monster.

>> he had me convinced that catherine was the bad guy and he was the good parent and these kids were abused and these kids were miserable. >> he did this for the kids. >> paul's sister ilona didn't believe a word of it. from the moment she heard a witness had come forward she believed her brother was being set up. >> this is michelle. you got rid of here. and now what happened? >> this is payback? >> i believe that's what it is. >> reporter: paul's girlfriend kat who got engaged to him in jail also believed michelle's story was suspicious. >> he's innocent. absolutely, positively. >> why are you so sure? >> he's just not that kind of a person. he's a caretaker. you know, it's like, his job as a paramedic defined him. >> reporter: and while paul had a squeaky clean record, michelle, his accuser, had issues. a history of depression and alcohol abuse. and she'd waited years to come

forward. >> michelle la france has been described as a scorned ex-girlfriend, a woman looking for revenge. did all that go through your mind? >> no. i don't believe that it did because after she leaves paul in january, february of 2011, it's 14 months before she gets up the courage to come forward to the police to tell the police what she knows, fully expecting that she's going to be arrested. >> do i need a lawyer? >> reporter: as paul waited for his trial to start, he told us he wasn't worried. >> there's really nothing that puts you at that crime. >> no. >> there's no eyewitnesses. do you think that's going to work in your favor? >> i think it's going to go rather well for me. >> coming up -- the prosecution is feeling confident too. did someone leave digital tracks? >> state police did a search for the toll records of that vehicle, and we had a hit at 6:39. >> but what, if anything, does

that prove? when "dateline" continues. new emergen-c protein fuel packed with plant-based protein antioxidants and real superfoods new protein shake new snack break new emergen-c protein fuel & superfoods emerge & see

- when you're volunteering, "it's not my job."r that's because right where you live, there's a need for your time and skills and effort and talent. please consider volunteering and feeling that feeling that you helped someone today. as paul novak prepared to stand trial for the murder of his wife, he insisted he was innocent. >> are you the evil murderer that some people think you are? >> no. not at all. >> any reason to kill your wife? >> no. no. absolutely not. i mean, when i left catherine, i

probably wasn't in love with her anymore. but i respected her, and she was -- she's the mother of my children. >> reporter: for catherine's brother michael the upcoming trial felt like opening an old wound. >> part of me wished i didn't get that phone call because i knew how traumatic it would be to the family and especially how traumatic it would be to natalie and nicholas. >> reporter: catherine's mom also knew a trial would mean more heartache for her grandchildren. >> i know no one could imagine how i feel losing my child. i can't imagine how they feel now with the loss of both parents in essence. >> all rise. the criminal court is now in session. >> reporter: in august 2013 the trial of paul novak began at the sullivan county courthouse. the district attorney opened the case. >> the evidence will show that as catherine begged and fought for her life the defendant ended her life.

murdering her in the basement of her own home. >> reporter: prosecutors set out to prove that paul orchestrated this murder down to the last detail. >> he was planning this for a period of weeks and maybe more in his own mind, of how to rid himself of catherine. >> he's a murderer. he's a sociopath. he planned. he executed. and he killed catherine novak in cold blood. >> reporter: their star witness was paul's ex-lover, michelle la france. the jury heard every minute of those police interrogation tapes of michelle describing the details of how he killed his wife. >> he told me that they were fighting and that they were rolling around on the basement stairs -- floor for like 45 minutes and that's why he was so late. and that she was screaming and begging him for her life. >> reporter: and the jury didn't have to just take her word for it. prosecutors called scott

sherwood, paul's partner from work, to the stand. they told the jury he had been interrogated by police and showed them the tape. >> let's go from the beginning. paul. you meet paul where? >> i met paul at his house in glen cove. >> reporter: jurors heard him tell police his version of what happened the night of the murder. >> so he gets in your red blazer. who's driving, you or him? >> i was driving. we were driving up toward where his residence was. where catherine still lived. >> reporter: sherwood said paul told him to park about a mile away from catherine's house and wait in the car. >> how long is he gone from the car? >> over an hour. >> and what does he say when he gets in the car? he said "it's done." he had said that the chloroform didn't work. "i had to strangle her," and something about hitting the gas line to ignite. >> so you knew the house was on fire? >> yes. >> reporter: as scott sherwood's story played in the courtroom, the prosecutors pointed out how

remarkably similar it was to michelle la france's. >> did he say where he strangled her? where in the house. >> in the basement. >> reporter: prosecutors felt these matching stories were powerful but didn't think they would be enough to get a conviction. they wanted physical evidence to prove michelle and scott were telling the truth. they began with sherwood's account of the drive up to narrowsburg. sherwood had told investigators paul asked him to stop at a walmart. >> when you get into the middletown area, you said you stopped where? >> at a walmart. >> and he went inside? >> he went inside. >> you waited outside? >> waited outside. >> and then he came out with a bag? >> yes. >> do you know what he bought? >> i believe duct tape. >> reporter: prosecutors showed jurors what investigators found when they visited that walmart. >> the state police found a receipt. only one receipt out of 30 registers that had three things on it -- duck tape, a hat and gloves. scott sherwood tells us that the

defendant used tape to tape up his scrubs, he had a hat and gloves on when he went and came back from the house. >> reporter: and there was more physical evidence to back up sherwood's account. he told police he and paul crossed the george washington bridge on their way back to paul's place the morning of the murder. >> was it a toll you guys went through? >> i would assume so. we went through i guess it was the lower level, but there was no booth -- there was no attendant. >> reporter: no attendant saw them pass, but detectives wondered could digital eyes help place the car at the toll booth? >> state police immediately did a search for the ez pass records, or toll records of that vehicle, and we had a hit at 6:39 of that vehicle coming across the george washington bridge lower level. >> that's huge. >> it's huge. >> it was a highly corroborative piece of evidence to corroborate scott sherwood. >> reporter: what's more, there was a photo snapped of the license plate. it was evidence that almost didn't exist. prosecutors say paul had planned to pay cash that night.

but construction at the toll booth forced him to drive through the ez pass lane. >> he made some mistakes. and he couldn't have anticipated the bridge was going to be under construction with no toll takers. >> reporter: and then prosecutors presented what they thought would remove any smudge of doubt from their case. a third person who linked paul to the murder. elyse hanlon, scott sherwood's wife. on the stand she recalled a conversation with paul where he told her that he committed the murder and that he did it alone. >> scott had nothing to do with it. there's no way scott's getting into trouble. scott had nothing to do with it. >> and he told her i went up there with him, he drove, i went in, i did everything. >> three people in three different rooms, telling us the same thing. you may not be able to say we have a fingerprint or we have dna, but that's pretty damning evidence. >> reporter: the last piece the prosecution needed was motive. why would paul want to kill his wife, catherine? simple, they said. money.

when catherine died, paul cashed in on her life insurance policy and homeowner's insurance. it all totaled around $700,000. >> the defendant said he would kill catherine and burn up the evidence, and he did just that. >> reporter: now it was the defense's turn to attack. jurors would hear more about the checkered pasts of the witnesses at the very heart of the case. coming up -- and what a very checkered past some of those witnesses had. >> i think i slept with half the town. crest's three dimensional whitening... ...removes stains,... ...whitens in-between teeth... ...and protects from future stains. crest. healthy, beautiful smiles for life.

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it was the defense's turn. paul novak would not take the stand to proclaim his innocence. >> it's my decision not to testify. >> reporter: instead his defense attorney, gary greenwald, did the talking. >> and i'm going to tell you you're going to have reasonable doubt. >> reporter: his argument, don't believe everything you hear. consider the source. consider the mental states of the key witnesses. consider their possible motives. he started by attacking paul's ex-girlfriend, michelle la france, the woman paul had thrown out of his house. >> she was a liar. she was manipulative, willing to take whatever steps necessary to hurt paul.

>> reporter: the defense tried to portray her as unstable, offering evidence of everything from suicide attempts to a bizarre drunken incident involving the police. >> it took six officers to take me down. and i apparently had to be handcuffed to a tree. topless. i had bruises from fighting the -- from fighting the tree. >> reporter: the defense attacked her credibility and used her own words to portray her as a liar who carried on a string of affairs with married men. >> i was sleeping around in mattituck. i think i slept with half the town. >> she was probably one of the most promiscuous people who i've ever seen testify in an open court. >> reporter: and the defense also argued scott sherwood suffered from serious mental health issues. >> scott sherwood from the time he was 8 years old was being treated for major psychiatric problems. and one of the crucial pieces of evidence was his psychologist, who testified that when he was put into a conflict situation would say whatever was necessary to get out.

>> i think what some people are going to have a hard time wrapping their head around is why three separate people would all lie. >> the reality is i take elyse out of the picture because she lied to support her husband. scott had a psychiatric problem. and he was manipulated in my opinion by michelle. michelle was a woman scorned. >> reporter: and the defense argued their stories were tainted because michelle had been given full immunity when she agreed to testify against paul, and sherwood made a plea deal for a reduced charge and a sentence of 3 to 12 years in prison. next, the defense went after the evidence that seemed to support sherwood's story, specifically that photo of sherwood's license plate taken the morning of the murder. >> one piece of evidence that seemed pretty damning was the ez pass record that showed scott sherwood's suv crossing the george washington bridge at the right time for this crime. >> the answer to that is very simple.

it proves nothing. there's a picture of the license plate. there's no picture of who's in the vehicle. how do you know as we're sitting here now that scott sherwood or possibly michelle were not in that vehicle? the answer is you don't. >> reporter: and greenwald dismissed that receipt from the walmart in middletown. >> is it just a coincidence that someone went into walmart around 1:30 in the morning the morning of catherine's death and bought a hat, gloves, and duct tape, all the things that were supposedly used in her murder? >> okay. first of all, mr. sherwood admitted under oath to me that he got to middletown at 12:00. he never could have been there at 1:30 or so because he was out by 12:15. >> reporter: still, there was an age-old motive, money, to explain away. and in our interview paul himself had an answer for that. >> are you having any financial issues at this point? >> actually, at that point i was in a much better financial situation than i had been

previously because i had ended up getting a second job at new york hospital in queens which was very high paying. >> reporter: and then greenwald called what he said was his most crucial witness, paul's landlord. the defense wanted to use him to undermine a key part of the prosecution's case. remember, scott sherwood said that after the murder he and paul drove home to paul's house. >> do you go straight to paul's house in glen cove when you come back? >> yes. >> reporter: but on the stand paul's landlord disputed that. he said he'd been outside setting up for a photo shoot starting in the early morning and didn't lay eyes on either of them. >> how could the man be out there and he never sees scott sherwood or paul? there's only one way. it didn't happen. >> reporter: the landlord's testimony was proof, the lawyer argued, that scott sherwood had made up his story. the defense closed its case claiming the prosecution had not proven beyond a reasonable doubt that paul was a killer.

>> paul novak is not guilty. and we ask you to find that. >> reporter: after seven weeks the jury finally began to deliberate. going into the trial, paul was certain they would find him not guilty. >> your life's on the line. >> yes, my life is on the line. but i think the truth will come out in the end. and hopefully -- hopefully those 12 people will know the true story. >> reporter: his fiancee, kat, told us before the verdict she will stick by him no matter what. >> i believe in him. >> have you thought about your wedding and where it will be, when it will happen? >> i actually already bought my dress. >> reporter: kat's future and so many others would be determined by what the jury decided. for catherine's family the waiting was the hardest part. >> i truthfully did not know what it was going to be. no matter which way you went with it, it was emotional.

there's no winners. >> reporter: almost five years after catherine novak's murder, so many secrets, lies, and betrayals had been revealed. so many questions raised. would the jury believe paul's ex-lover and his ex-partner? was paul a ruthless killer, or had he been set up? it took the jury two full days of deliberations. on the third day they had made a decision. the verdict was in. >> we find in the case of the people of the state of new york versus paul novak as to count 1, murder in the first degree. >> guilty. >> reporter: guilty. convicted of first-degree murder. paul showed only a slight head shake as he was convicted of all charges against him, including insurance fraud, grand larceny, and arson. >> how are you feeling right now? >> not very good. >> reporter: paul was sentenced to life in prison without the possibility of parole. plus 20 to 60 years.

but michelle, who knew about the murder plan from the beginning walked away a free woman. >> a lot of people will be angry and think this woman knew about a murder that was going to happen and didn't do anything. >> is it a perfect world? no. will she get hers? yes. when she dies. >> as for kat, she continued to stand by paul. and the couple married in 2018. the future for the children will be decided by the people who love them most, paul and catherine's families. >> we will work to get for those kids what catherine wanted for them. >> up in narrowsburg where catherine novak's beloved red house once stood, the trees glow orange and gold. autumns have come and gone. her mother still mourns the daughter she lost, but remembers the life she lived. >> what do you miss most about her? >> her smile and her hugs.

she was a lot of fun, catherine. she enjoyed life a lot. >> that's all for this edition of "dateline." i'm craig melvin. thank you for watching. as president trump tries to fight an escalating impeachment battle, we've learned a second whistle-blower has come forward and is raising similar concerns about trump's july 25th phone call with the president of ukraine. >> plus, the president seems to have a new defense for the ukraine scandal. he's reportedly told house republicans he made the call at the urging of energy secretary rick perry. >> the white house says turkey will soon be moving forward with an operation in turkey and will be responsible for all isis fighters captured within the past two years. ♪ good morning, everybody, it is