denitive expressions of an intent to denuclearize. >> although they've g -- they're further along. so their bargaining position has chand. victor cha and tim shorrock, that was a great conversation. i really appreciate it. >> thank you >> that is "all in" we were like sisters. i have a picture of her. >> first she disappeared. >> i knew right then that she absolutely never made it into her house. >> then her wealthy boss did. >> we three kings be stealing the gold. >> melissa had had a three-week, you know, thing -- >> fling with the boss?

>> a billion, billion and a half dollars. >> he told me he had gotten in over his head with not-so-nice people. he said, if i don't get this taken care of, these people will put a bullet in my head.

the boldest, brassiest bunch of politically connected lawyers in florida. the rothstein law firm. >> had a gorgeous, panoramic view out to the ocean. >> from a few guys with law degrees to a juggernaut by the mid 2000s, with more than 70 attorneys led by scott rothstein. mike mayo was a columnist for the "ft. lauderdale "sun sentinel." >> he probably thinks i'm king of the world. >> and the firm is where melissa lewis, a by-the-book attorney found great success for herself

and her clients. she was by all accounts a workaholic who loved what she did. no shrinking violet either. melissa loved these boozy, splashy office parties just as much as the other lawyers. she'd found herself a nice slice of the american pie. and that's the thing about 38-year-old melissa lewis. even as she raised her voice and glass with the senior partners, her sad end wasn't far off. and her unexpected death would get caught up in a chain of events right out of a john grisham novel. murder, betrayal, and millions in fraud. melissa lewis at the start of everything awful that followed. >> it ended up being the beginning of the end. >> missy, as her family called her, had some so far. penthouse lawyering wasn't likely for a restless high school dropout. her mother, lisa lapoint. here was a kid who didn't really

finish high school. she got the ged ticket. >> correct. she didn't plan to be a high school dropout. she was in a hurry to get on with life. >> and focused enough finally to finish college, and in her late 20s, go for a law degree. she breezed past the younger students to become the prestigious editor of "the law review." she caught the eye of one of her professors, scott rothstein, who took her on as an intern. office manager debra villegas met her on the first day of work. what did melissa bring to the party? >> she was smart. capable. she was everything you would want in an associate attorney. >> she was also one of the nicest people debra says she ever met. they were fast friends. >> we were like sisters. she knew all my faults and flaws. and she loved me anyways. >> reporter: debra and melissa saw the firm grow tenfold in just a few years. their gregarious boss, scott

hobnobbed with big names in sports, politics, and business. even future presidents. fundraisers -- scott was your man. >> once your name gets out, you truly cannot imagine how many people knock on your door. >> the door scott knocked on was melissa's. >> melissa was the one, he knew she could handle it, she wouldn't let anything fall through the cracks. >> melissa specialized in employment law but volunteered her time for battered women and victims' rights. she also worked on building a memorial garden for crime victims. >> she was always a champion for the underdog. >> melissa eventually met a lawyer from a different firm and married. debra was a bridesmaid. after five years, her best friend's marriage had come undone and ended in a messy divorce. >> that divorce just devastated

her. >> after melissa's divorce, she took a second full-time job -- best aunt offer. carrie is her sister. she didn't have children? >> no. she didn't want to have children. she wanted her career. >> when her marriage was in trouble and hitting the rocks, separation, melissa was there for her, too. playing the same great aunt role for debra's four kids. the two became inseparable at work and outside the office. >> she's cooking for me and the kids, and we have movie nights on saturdays. >> after her divorce, a still-shaky melissa started dating a little, but work, not relationships, would occupy her front and center. eventually her diligence paid off. in 2008 after seven years at the firm, the former intern was made the first female partner. >> she shared with me early on that she hoped to be a judge one day. >> and debra had done well for herself, too. after all those years working as a paralegal and keeper of the supply cabinet, her boss promoted her to chief operating officer.

not bad for someone who never finished college. things were going really well at the rothstein law firm. >> yes. yes. >> then came march 5th, 2008. just one week after melissa had been made partner. it was a wednesday night. debra tried to call her several times but got no answer. the next morning when melissa was a no-show at work, debra called her friend repeatedly but to no avail. then she got ahold of her sister, carrie. >> carrie was like me, oh, no, something's wrong. >> debra told her boss, scott. well-connected attorney that he was, he called a police officer he knew in plantation, florida, where melissa lived. the officer agreed to meet debra and carrie at melissa's house. when they got there, everything seemed to be normal. nothing was tossed? >> no. the only thing amiss was in her garage. >> melissa's car, her caddy suv, was gone. they all clued to something bizarre -- a fine mist of what looked like orange spray paint

throughout the garage. whatever the stuff was in the garage affect you? >> yes. i started coughing really bad. i said, that's pepper spray. >> pepper spray. like many women, melissa was known to carry a canister of it for self-protection. had she been attacked? had she used it? >> i knew right then that she absolutely never made it into her house. >> something had happened in that garage, something very disturbing. and it wasn't looking good for rising attorney melissa lewis. >> the answer comes all too soon. at lowe's our "grow together" planting system takes the guess work out of creating a beautiful yard. shop lowe's and save with pint annuals now 5 for $5. ♪

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ft. lauderdale attorney melissa lewis was missing, and friends and family were in a panic. she hadn't responded to phone calls, and didn't show up for work. she's not one to take a mental health day? >> no. uh-uh, no. >> reporter: this was going to be a high profile case. melissa's boss, scott rothstein, was a power broker attorney who had a little extra juice with local police. plantation police detective brian kendall. >> he was our union attorney, they knew him, they were friends of his. >> reporter: at melissa's house the mysteries piled up. her car was gone, and there was pepper spray all over her garage. melissa also had a dog, and there was pepper spray on the dog's face as well. you're in foul play country with

this investigation. >> our concern is raised greatly at this point that she is in some sort of danger. >> reporter: detectives wanted to know what melissa had been wearing the previous day at work. debra knew exactly: a new brown pants suit with pink pinstripes. sure enough, there she was -- captured on security cameras in her office lobby talking with another lawyer at 7pm. after leaving work, her sister carrie said she then went to the supermarket. how'd you know she'd gone to the supermarket? >> she actually called my daughter -- that night. she was the last one to speak to her. and she said, "i'm going into publix." >> reporter: detective kendall checked store surveillance video. there was melissa in the cosmetics aisle reaching for something on the shelf. later the cameras showed her leaving, documenting the start of her pathway to doom. you got a timeline and you know what she's wearing, huh?

>> now we have a time stamp on when we believe she arrived home, based on the distance to the publix, the distance of her -- her house. >> reporter: it was probably around 8:30. from the pepper spray on the walls and floor, it appeared melissa came home and was attacked inside the garage. detectives also found a small button on the garage floor, perhaps ripped from that pantsuit. then one detective had an idea: use the gps and security system in melissa's vehicle to locate it. >> it's a cadillac. cadillac has onstar. they're able to activate the onstar, tell us the location of the vehicle through gps, and brought us right to this parking lot. >> reporter: the car was about a half mile from melissa's house in this medical office parking lot that melissa never went to. and through onstar, you could remotely open the vehicle, huh? >> they were able to unlock the vehicle for us. >> reporter: inside the suv, disturbing clues. what do you find? >> we find a suit jacket that she was wearing the night before and on the suit jacket, there was a missing button. and that's significant because the corresponding button was found on her garage floor. >> reporter: the jacket smelled of pepper spray, too. there were two shoes found in the car, but nothing else. melissa had been wearing a sterling silver ring, diamond earrings and a $5,000 watch.

she also had an expensive prada handbag and an iphone. could very well be a target of some opportunistic grab and run. >> at the point we find her vehicle, we have no clues, no leads, and we don't have any suspects identified. >> reporter: police did find a tiny drop of melissa's blood in her car and on a tile in her house. but there were no fingerprints other than melissa's in either place. dna testing would take longer. now the question is, where's melissa? >> that's the million dollar question at this point. >> reporter: two days after she went missing, a worker made a gruesome discovery as he was clearing debris from a water pump at a nearby canal. poking around with his rake, huh? >> guess the first thing that comes to his mind is, "ah, it's just a mannequin." then he realizes it's actually a body. >> reporter: it was 38-year-old melissa lewis.

the missing persons case was now a murder investigation. >> still a whodunit. we have no idea. >> reporter: the news media quickly picked up on the story. >> my husband told me. he saw it on the news. >> reporter: how did -- how did he tell you? what was the -- >> he came to my work and told me. and i just broke down. i couldn't believe it. >> reporter: police called the victim's best friend, debra. >> when they told me that they had found her body, i just collapsed to the ground. >> reporter: your friend melissa was dumped into a drainage canal. >> this beautiful, wonderful person who was nothing but kind. >> reporter: when the medical examiner's report was completed, it showed she had been strangled. >> that is such a personal thing to do to somebody, to have to look them in the eyes and do that. >> reporter: an up-close and personal killing. no question. but those timeless questions of

all investigations went unanswered, who and why? >> coming up, a person of interest, very close to home. >> i said, no, he better not have done anything to her. >> a missing cell phone of great interest to police. when "dateline" continues. >> reporter: the hunt was on for

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>> reporter: the hunt was on for a suspect in the strangulation murder of melissa lewis. the lawyer's body was found

floating in a canal two days after she went missing. as they always do, detectives looked at the circles she moved in. was there something in the background of my victim here that accounts for what's happened to them? >> we don't think so. she doesn't live a high-risk lifestyle. she's a prominent attorney. she's safety conscious, you know, she carries her pepper spray. >> reporter: melissa specialized in people with gripes, employment lawsuits -- detectives couldn't find any history of bad blood between melissa and her clients or people she had sued. detectives talked to the ex-husband, but his alibi was solid. and then they looked at the current men in her life. what about boyfriends? she was a single woman who had been dating some guys. >> we assigned detectives to go out there, talk to them, and they were alibied out pretty

quickly. >> reporter: of course, they also wanted to talk to melissa's co-worker and best friend, debra. >> who better to talk to than someone's best friend to find out what their habits are, what they like to do? did she have strange men come to her home? >> reporter: far from it, debra told detectives. most nights, melissa was either at debra's house cooking dinner for her and her kids, or home with her dogs, george and gracie. still, they continued to pick debra's brain. >> it's just a million -- you just can't even imagine, like, the questions that they ask you. >> reporter: detectives also talked to melissa's sister, carrie. when asked who she thought might have done this, her reaction was immediate. >> i said, "oh, no. he better not have done anything to her." >> reporter: who was he? >> my ex-husband. because we had just gotten divorced. and he knew my sister. he got served by her firm. >> reporter: so you thought he -- if she's gone missing, he might have something to do with it. >> yup. she said that he had come to her house. just -- it kind of scared her. >> reporter: detectives found out he had a record, so they checked out the sister's ex. >> he was a subject of interest early on in the investigation. he came in. he consented to any type of questions we asked of him.

he voluntarily answered them. he had been released from prison -- in the past. >> reporter: so you haven't ruled him out yet? >> not yet. >> reporter: with the list of possible suspects shrinking, detectives shifted their focus to something that might provide their first break in the case. with melissa's iphone missing, detectives put in an emergency request to the phone company to see if it could help track her cell. when he got the report, detective kendall couldn't believe what he saw. melissa's iphone had been active after the murder and someone had actually gone into her voicemail and played back messages, read texts. >> we try to make sense as to why he would want to do something like this. >> reporter: police were dumbfounded that someone wouldn't know that a smartphone was a detective's best friend and police could track them using cell towers. it was either bold or stupid or both. people know this concept of pinging off towers. it's -- the cell phone is telling the towers, "here i am"?

>> yeah. so it's giving us a general vicinity and -- of an area, where -- that cell phone communicated. >> reporter: and the phone records showed that person had been on the move from the believed time of the murder into the next day. how important is the story told by the cell phone? >> very important. cell phone's almost like someone dropping pieces of popcorn, leaving a trail. >> reporter: but the trail was a wide one. cell phone towers don't pinpoint exact locations. >> we know from that cell tower there is maybe three to four-mile radius from that tower that we're looking for to try to figure out where that phone is. >> reporter: investigators believed melissa was killed in her garage around 8:30 p.m. wednesday. that night, her phone went south from her home in plantation, eventually stopping in an area

in miami gardens. >> from midnight till about 5:00 am, the phone's in one location. >> reporter: thursday morning, the phone went northeast to fort lauderdale then went further north to pompano beach. shortly afterwards, it turned back towards fort lauderdale. but somewhere along the way, the signal was lost. either the battery died or the killer dumped the phone. all told by thursday, the day after the murder, the phone or whoever had it travelled a distance of about 60 miles. >> so obviously, who's with that cell phone, was most likely the last person that was with -- with melissa. >> reporter: detectives also focused on those five hours the phone was stationary in miami gardens. was the killer home in bed? >> we have to identify if melissa knows somebody that lives in this area. >> reporter: does anything come up at that point? >> no. we have no reason to believe anybody she's dating, anybody she knows lives there. >> reporter: melissa's family confirmed that. police asked everyone remotely involved in the case and the answer kept coming up no. by now, police had also cleared the ex-husband of melissa's sister. he had no connection to the area either. but when they asked debra if she knew anyone who lived around there, her jaw dropped. she said she did know someone. >> i was like, i just do not think it was him. >> reporter: but cops are funny,

they don't just take people's words for things. they check them out. >> police have identified and cleared a number of potential suspects, but now there's someone new on their radar. the revelation would rock melissa's friend debra. why would he want to kill her? >> coming up, a new suspect, close to debra but who barely knew melissa. so why would he want to kill her? >> she couldn't connect the dots that put him in the garage with her friend. >> absolutely not. >> i remember i couldn't stand up. i wasn't able to stand on my feet. >> when "dateline" continues. [ doorbell rings ]

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welcome back. i'm craig melvin. desperate to find melissa lewis' killer, police turn to technology to help unlock the secrets in melissa's phone. what they found sent them hurling in an unexpected direction. here again is dennis murphy with "betrayed." >> reporter: melissa lewis' cellphone was looking to be the key to unlock the mystery of what happened to her the night of her murder. >> the phone stayed with the person that we believe took melissa. >> reporter: now they were focused on miami gardens where the phone had been stationary for several hours after the murder. police asked melissa's best friend, debra villegas, if she knew anyone who lived in that area.

>> debbie says, "my husband, tony, who i'm going through a divorce with." >> reporter: debra was dumbstruck. tony? melissa? >> he would have no reason to do this to melissa. she's never done anything to him. >> reporter: so you're telling the detectives, "you're looking at the wrong guy." >> yeah. >> reporter: did tony know melissa? >> he had met her a few times, you know, over the years, but we weren't social. >> reporter: debra told police she and tony had been married for 17 years and had four children. they had separated more than a year earlier. tony had then moved into a house in miami gardens with a friend. for twenty years, he'd worked for florida east coast railways hauling freight. >> you know, he basically drove a train for a living. >> reporter: police checked him out on their computer. has he any priors? >> none. no priors. >> reporter: detectives went to talk to tony and recorded the conversation. >> how well did you -- do you know this -- your -- debra's -- debra's friend? >> melissa. i know her from her. i've seen her a few times. >> you guys ever have any problems, maybe? something like that?

>> never. never. i don't think i ever spoke to her more than two words. >> do you know if she's had anything to do with what you're going through right now with debra and the divorce? >> i don't know. and i really don't -- don't care. i mean i just -- >> that wouldn't bother you if she did? >> oh no. the thing is that i just want to get away from my wife. i just wanna be at peace. >> reporter: then they asked him the question. >> did you have anything to do with -- with melissa's death? >> no. >> reporter: but what tony didn't know is that before detectives spoke to him, they had obtained a copy of the train route he drove the day after the murder. and guess what? it matched the route traveled by melissa's phone. detectives confronted him with the evidence. >> her phone, after it was stolen, drove to the area of your house and stayed there overnight. and came to work with you the next day. and traveled north with the train, because the train has gps on it, doesn't it? >> uh-huh. >> it was on the train. okay? unless someone else here knows melissa, lives in your house, comes to work with you, you had the phone. okay? listen, this -- i'll be honest

with you. this doesn't look very good for you. >> but i don't even know her. >> reporter: detectives searched tony's house, his car and his train, but never did find melissa's phone. and there was still a missing motivational piece to this puzzle. why in the world would tony kill someone he barely knew? and yet, tony said something during his interview that opened a window into a private side of his character. he was capable of intense jealousy when talking about his estranged wife. >> the few times i've picked up my kids, she has guys in there, so i always told her i don't like flies on my meat. and -- and i love her. i gave all my life to her. >> but it wouldn't bother you that -- if she's spending a lot of time with melissa? that wouldn't bother you? >> no, no. >> reporter: despite what tony

said, detectives thought the crude comment had a broader meaning, speaking to the bff relationship of debra and melissa. does he feel like he's been tossed out of the house because melissa has taken his place? >> i think he definitely believes that melissa was a catalyst to enable debbie to go forward with the divorce. he kills melissa lewis to get back at debra for divorcing him. >> reporter: but if you're lethally angry about an impending divorce, why not kill the wife? >> if he kills melissa and he's caught, debbie's still there to raise their kids. >> reporter: although tony would later deny it, debra told detectives he had been violent with her and her kids in the past. because of that, debra said she had decided on her own that tony had to go. you thought he was physically gonna hurt the kids? >> no, he was already physically hurting them. i thought he was going to go too far. >> debbie was scared of tony. but didn't raise any suspicion as to why he would want to ever harm melissa. >> reporter: she couldn't connect the dots that put him in that garage with her friend.

>> absolutely not. >> reporter: maybe senseless to the wife, but those dots were starting to connect for detectives. they eventually shared their suspicions with debra and how the evidence of the travelling iphone pointed to tony. >> i remember that i couldn't stand up. i wasn't able to stand on my feet. >> reporter: melissa's murder was devastating and frightening for everyone at the law firm, especially it seemed for scott rothstein. only the week before, rothstein was toasting melissa after making her partner. now, he was helping her family with funeral arrangements. melissa's aunt, lynn haberl, spoke at the church memorial. >> i could look out from the podium and see a sea of lawyers out there. >> reporter: including scott rothstein? >> including scott rothstein. >> reporter: who actually paid for the funeral. >> he actually paid. he came to the funeral home and paid for everything. >> reporter: three days after the funeral, detectives arrested tony villegas. he was charged with first-degree murder. >> he denied involvement in this.

>> reporter: tony's attorney is bruce fleisher. >> they sought the death penalty. >> reporter: police and prosecutors were confident they had a solid case against tony villegas, but something happened that threw the whole investigation into freefall. that's because new crimes were about to be revealed. and new questions were about to be raised about who really killed melissa. and in the midst of it all, scott rothstein, like melissa, would disappear. >> coming up -- were melissa and scott rothstein's disappearances connected? >> we three kings be stealing the gold. >> the dark secret buried beneath all these rothstein riches. >> he said if i don't get this taken care of, somebody is going to put a bullet in my head. each day justin chooses to walk. at work... and after work. he does it all with dr. scholl's. only dr. scholl's has massaging gel insoles that provide all-day comfort. to keep him feeling more energized. dr. scholl's. born to move. ♪

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>> reporter: debra villegas' world had been turned upside down. her best friend, melissa lewis, had been murdered and debra's estranged husband, tony, was charged with killing her. >> people thought, "debra's psycho ex-husband has murdered melissa." you know, i was just overwhelmed with guilt and shame. >> reporter: melissa's murder weighed heavily on debra's mind, as well as the mind of her boss scott rothstein. but scott seemed to be rattled by something more than just melissa's murder. for some reason after tony's arrest, rothstein beefed up his own security. who was he afraid of? >> obviously that he was next. >> reporter: but if melissa's

murder had been solved, why was scott still worried? debra knew because she was privy to a secret that threatened to send even more people to prison, and to destroy scott rothstein's reputation as a high-profile mover and shaker. >> he could pick up the phone and call and make things happen. >> reporter: a walk through his office left no doubt. his hero wall was plastered with pictures of him with politicians, business moguls, and movie stars. the governor was on speed dial. it had been a heady ride for a boy from the bronx, by no means shy about his success and who liked to joke about how he got there. >> that's right. we're breaking the [ bleep ] law. we're lawyers. if we're not gonna break the law, who is? >> reporter: he had his trophies for sure, a waterfront mansion with an 87-foot yacht out back. his fleet of cars included a million-dollar bugati, a maserati and a lamborgini. his wrist always flashing an expensive watch from his collection. why did he want all that stuff?

>> he wanted people to look at him and say, "that's a successful guy, and he knows everybody." >> reporter: rothestein's bragadoccio success and conspicuous bling had already caught the eye of "ft. lauderdale sun sentinel" reporter mike mayo. >> i was asking, "how is your firm making all this money?" he said, "well, we've come up with a formula where we -- we're not going to trial. we're settling cases before trial." >> reporter: the cases were age and sex discrimination lawsuits. rothstein figured out a way to file the cases without the firm paying to do it. instead, he found investors willing to fund the lawsuits. they were promised a fantastic return for their investments, once the cases were settled. attorney sam rabin represented a banker who did business with scott. >> the investor would give the $5 million to rothstein. he in turn would tell the investor, "i'm gonna give you $6 million in six months." >> reporter: but behind the scenes there were big problems as debra learned about a week before melissa was murdered.

>> he told me he was in trouble. he had gotten in over his head with some not-so-nice people. and he said, "if i don't get this taken care of, these people are gonna put a bullet in my head." >> reporter: scott then asked her to cross the line and forge signatures on documents. >> i knew this is something that shouldn't be going on, but you know what? it was gonna be a one-time thing. >> reporter: it wasn't. scott asked debra, his chief operating officer, to do it again and again. the reason, the cases were made up, phonies, and the forged documents were used to fool investors. >> the settlements were not real. >> reporter: there was no client? >> the cases were fabricated. >> reporter: it turned out it was all a ponzi scheme. mr. high-flyer scott rothstein didn't use investor money to file lawsuits. instead he used that money to fund his champagne and yachts lifestyle. >> we three kings be stealing the gold. >> reporter: in the end it would be the largest ponzi scheme in florida history. how big did it get? >> ballpark, $1-1.5 billion. >> reporter: and then halloween eve, 2009.

more than a year had passed since melissa's murder with tony villegas still sitting in jail awaiting trial, and another twist to the story. >> scott rothstein has disappeared. >> reporter: unlike melissa, scott was not a murder victim. but he was a fugitive, a bernie madoff figure on the run. he had left the country in a private jet for morocco with $16 million in cash and his collections of watches and jewelry, fleeing after learning unhappy investors had gone to the fbi. one month later, he was back in florida, but not under arrest. what no one knew was that scott had cut a deal with the fbi to act as an informant. >> this is scott rothstein, november 16th, monday, 1:43 p.m. >> reporter: he wore a wire and helped convict 26 people involved in his ponzi scheme. and despite his cooperation, in 2010, he was sentenced to 50 years in prison. but one big question emerged,

speculation about that woman in the firm who'd been killed. >> whether melissa knew about the ponzi scheme is one of those great mysteries. >> reporter: scott had started his ponzi scheme three years before melissa was murdered. >> is it time to take a fresh look at the whole melissa lewis murder? is there something more sinister? >> reporter: detective brian kendall now had a whole new problem with his fairly straightforward case against tony, the jealous train engineer. is this woman, melissa, killed because she knew too much? >> after we think we had this solid, buttoned-up case, "we do have the whole scott rothstein ponzi scheme comes into play?" >> reporter: the fbi combed through the detectives files looking into a melissa-rothstein-ponzi link. >> they spent a week going through every inch of that case to find out if there was a connection to scott rothstein. >> reporter: with all these messy complications, tony's

defense attorney, bruce fleisher, thought about two words, reasonable doubt. >> a lot of people thought that because of the rothstein ponzi scheme, that he had something to do with the murder of melissa lewis. >> reporter: and debra villegas was back in the hot seat herself, being grilled by homicide detectives who bluntly asked her about scott, the ponzi scheme and melissa's murder. she had her lawyer with her this time. >> was melissa aware of anything that scott was involved with? and i'm -- i'm gonna use a term the ponzi scheme. >> no. >> reporter: and then the questioning got more direct. >> any discussion between you and scott about having melissa killed? >> absolutely not. >> are you aware of any discussion or conspiracy to hire tony for melissa lewis' murder? >> no. before i would have let him kill melissa, i would have let him move back into my house. that's the biggest regret that i have in all of this. >> reporter: but detectives did learn one new thing about melissa and scott, some dish. >> she had an inappropriate relationship with scott. >> with scott. >> melissa had had a very, very brief, like, a three-week, you know, thing --

>> reporter: fling with him, with the boss? >> with scott. oh, god, melissa. it so doesn't matter. >> reporter: but it had been years before, when melissa was first hired out of law school. detectives discounted it, saying it had nothing to do with melissa's murder, and was not relevant. and, of course, rothstein himself was grilled about melissa lewis' murder during depositions in civil suits brought by the investors. >> we asked him directly whether or not he was involved in any way in -- in the homicide, and he vehemently denied it. >> reporter: how did he take it? >> he was indignant. but he was also a great actor, because he was a sociopath. >> reporter: in the end, neither the police, nor the fbi could connect melissa's murder to rothstein, and his ponzi scheme. so what happened to his loyal aide debra? she pleaded guilty to money laundering and the judge came down hard. and you went away to federal prison? >> i did, with a 10-year sentence. >> reporter: the sentence was later reduced to four years. meanwhile, years had gone by and debra's ex-husband tony still

hadn't gone to trial for murder. he sat in jail, all but mute, his lawyer claiming a malady that might prevent him from ever seeing a judge and jury. >> coming up, finally, eight years after melissa's death, tony villegas would stand trial. but what would the jury make of such a strange murder? >> you have these domestic homicides all the time. but this had a twist to it. >> when "dateline" continues.

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>> reporter: a funny thing happened to tony villegas on the way to the courtroom. he'd exhibited bizarre behavior and stopped communicating with his attorneys and was declared mentally incompetent to stand trial. still in custody, he was in and out of treatment facilities for years until doctors found him competent again. finally, in the summer of 2016, eight years after the murder,

tony went on trial. >> the defendant in this case -- >> reporter: the prosecutor shari tate argued that tony, fueled by a jealous rage, waited in the bushes for melissa to come home, followed her into the garage and then launched a brutal attack on his wife's best friend. >> it is a hands on, personal murder. it takes time. it takes premeditation. and, why? because she was a friend. >> reporter: but the residue of pepper spray all over the garage was evidence that melissa had fought back and some had apparently gotten on the killer. tony's housemate testified the night of the murder, he saw his roomie scrubbing his arms. >> he said that, um, he got pepper spray on him and that his hands were burning and itching. >> reporter: then, an expert on cellphone tracking told the jury tony had both melissa's phone and his own personal phone with him the night of the murder and

the next day when he was driving his train. >> they moved north and then back south along the railroad. >> reporter: but now prosecutors had to tackle the head scratching question of motive. why would tony kill melissa in the first place? debra villegas testified that tony became very jealous and angry with melissa because she'd virtually replaced him in the household. >> was melissa helping you through this difficult time in your life now, through this divorce? >> yes, ma'am. >> reporter: and that was the theory. in order to get back at debra, he killed her best friend. >> you have these domestic homicides all the time but this had a twist to it because he didn't kill debra. >> reporter: then tony and debra's 23-year old son, caleb, was called to testify against his father. the usual blank stare on tony's courtroom face changed as his son recalled how his father blamed melissa for the divorce. >> did he tell you that it was

melissa's fault? >> he -- he believed that she had a part in it. yes. >> did he tell you that he was mad at melissa about this? >> yeah. he was mad about the whole situation. >> reporter: oh, and there was one more thing. remember melissa's jacket, the one found in her suv? tests showed tony's dna on the jacket. prosecutors believe tony wiped his nose with it after being pepper sprayed. >> odds of finding an unrelated individual with that profile are rarer than one in 30 billion. >> reporter: you couldn't have had better evidence if you had a movie of him killing her. >> right. >> reporter: the defense had been dealt a poor hand to play, but attorney bruce fleisher chipped away at each state witness, starting with tony's housemate, the guy with the scrubbing away pepper spray story. the defense said he had 250,000 reasons to make his story up. >> there was a reward offered. >> yes. >> and who offered the reward? >> scott rothstein. >> and, how much was the reward in the case? >> $251,000.

>> reporter: ironically, he never got the reward. the collapse of rothstein's ponzi scheme put an end to that. and as for the prosecution's theory of motive, fleisher argued it was as thin as it was nonsensical. >> you would think that if you were so enraged that your wife were doing this that you'd wanna harm her, and not someone else. >> reporter: as for debra villegas, defense attorney fleisher surprised everyone when he didn't ask her a single question. but he did go after the son, caleb, challenging him as to why he sat for so long on this story about his father badmouthing melissa. >> you didn't tell your mother about that when you first heard about that, did you? >> no. i didn't see any relevance. >> and when you spent time with him, things were good? >> yes. >> you love your dad? >> yes. >> reporter: would jurors notice the tear rolling down tony's cheek? so, onto the scientific evidence, the cellphone first. lawyer fleisher found a mistake

in a chart the state's expert had used. was the expert analysis, in fact, sloppy? if you're such a hot shot expert -- >> right. and -- >> reporter: how does this error creep in? >> and he said, "well, it was a mistake." >> reporter: the same went for the dna evidence, attack the credibility of the analysis. the defense said the dna results, returned within a few days, were rushed through the police lab because of rothstein's connections. attorney fleisher also suggested there could have been cross contamination to tilt the scale so the results pointed at tony. >> our goal was to educate the jury on the rothstein connections, and the rothstein influence. >> reporter: had meddled with the physical evidence? contaminated it maybe? >> we can only speculate. but when a man is as powerful a guy as -- as rothstein was, people would think that they could do things. they could conjure up dna. >> reporter: and use it to frame tony villegas. before the defense rested, the judge asked tony villegas if he wanted to testify.

>> is it your wish to testify or remain silent? >> silent, sir. >> reporter: in closing arguments, prosecutor tate said all the evidence pointed to tony. the pepper spray, cell phone records, and the dna. >> there is not one other person on the planet earth that could leave the dna on this jacket. >> reporter: the defense reminded jurors that the pepper spray evidence was weak, and that both phone records and dna results could be manipulated. >> the pieces of the puzzle do not fall into place, because reasonable doubt prevents them from falling into place. >> reporter: the jury now had the case. outside the courtroom debra villegas saw melissa's family for the first time in eight years. >> all these years later and it just washed over me like -- like it had just happened. you know, that -- that i caused these people a kind of pain that's unimaginable. >> reporter: later that afternoon, the jury sent out a

note. "verdict." as the verdict was read, debra sat with melissa's family, consoling her niece. >> tony villegas is guilty of murder in the first degree. >> reporter: tony's face was blank. before sentencing, melissa's aunt, lynn haberl, addressed the court and said directly to tony. >> we forgive you because we must and release you into god's hands for all eternity. >> reporter: sentencing was immediate. >> sentenced to spend the rest of your natural life in a florida state prison. >> reporter: after tony was led out of the courtroom, melissa's family went to his people and hugged them, then all cried together. >> my heart broke for them. it is a legacy for their family. >> reporter: melissa's own legacy is something called the garden of reflection. before her murder, she worked for victims' rights, and raised money to build it. now, her name is inscribed there, too. the victim, as prosecutors told it, that in the end had nothing to do with knowing too much

about a notorious scandal, but a victim simply of an all consuming jealousy. >> that's all for now. i'm lester holt. thanks for joining us. i'm craig melvin. >> i'm natalie morales. >> and this is "dateline." i learned that he was arrested. i was shocked. i was just so confused. i didn't think it was real. >> in the world of the ivy league, he was the total package, star student, gifted athlete, wildly popular. >> he is one of the nicest guys ever. >> no one could understand how a weekend visit to his parents' house -- >> you have a set?