but the problem, then as now, is time. i'm craig melvin. >> i'm natalie morales. >> and this is "dateline." >> we were like sisters. we had shared so much. they told me that they had found her body. i just collapsed. she's dead because she was my friend. >> first, melissa disappeared. >> where's melissa? >> that's the million dollar question. >> i knew right then that she absolutely never made it into her house. >> left behind in her garage signs of a struggle and a strange orange mist. >> we didn't know what it was.

>> then, her boss went missing, too. >> who was he afraid of? >> he might of been afraid that he was next. >> he said, "if i don't get this taken care of, these people are gonna put a bullet in my head." >> he left behind a bigger mess. >> we three kings be stealing the gold. >> a missing fortune. >> ballpark? $1-1.5 billion. >> a missing woman. >> we have no clues, no leads. >> some wondered, was there a link? >> this had a twist to it. >> two crimes. one for money. one supposedly for love. and behind both, a lingering mystery. >> it's just so ugly and so wrong. and i can't fix it. welcome to "dateline." hot shot florida attorney melissa lieu wigs was living large in ft. lauderdale, but then her seemingly charmed life ended in tragedy, her body was discovered in a drainage canal.

she had been murdered. but who would want her dead? with few clues, fewer suspects and the scandal involving her law firm, investigators had their work cut out for them to unravel the mystery of what had happened to melissa. here is dennis murphy with "betrayed." >> reporter: if you ask someone in town where the buzziest part of ft. lauderdale lies, they'll probably steer you here. las olas boulevard. and way up there in this high-rent district is a penthouse office suite that once upon a time was home to a high-powered law firm. the boldest, brassiest bunch of politically-connected lawyer

players in south florida. the rothstein law firm. >> it had a gorgeous, sweeping, panoramic view. all the way out to the ocean. >> reporter: 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. >> reporter: and the firm is where melissa lewis, an earnest, 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 those 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 billions of dollars in fraud. melissa lewis at the start of everything awful that followed. >> it ended up being the beginning of the end. >> reporter: "missy," as her family called her, had come so far. penthouse lawyering wasn't likely for a restless, likely for a restless, high school dropout. her mother lisa lapointe. 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. >> reporter: and focused enough, finally, to finish college and then in her late 20's go for a law degree. she breezed past the younger law students to become the prestigious editor of the "law review." and 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 her first day of work. what did melissa bring to the party? >> she was smart and capable. you know, you -- she was everything you would want in -- in an associate attorney. >> reporter: she was also one of the nicest people debra says she ever met. the two became fast friends.

>> we were like sisters. she knew all my faults and flaws and -- and she loved me anyways. >> reporter: debra and melissa saw the firm grow tenfold in just a few years. their gregarious boss, scott, was the front man. he hobnobbed with a who's who of big-deal names in sports, politics and business. even future presidents. fundraisers? well, scott was your man. >> once your name gets out there you truly cannot imagine how many people knock on your door. >> reporter: and the door scott knocked on was melissa's. >> melissa was the one that he knew she could handle it. he knew that she wouldn't let anything fall through the cracks. 1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years.

whthe moment you realize you didn't really mean "any color you want." we want you to feel great about your color choice. that's why we have a paint guarantee. if you don't love it, we'll replace it. whimper yap yap yap yip is your dog trying to tell you something? licking, scratching, scooting, and rubbing may be signs of allergic itch, a medical condition that may require treatment. that's why there's prescription apoquel: the revolutionary medicine

that's giving millions of dogs the relief they deserve. apoquel goes to the source of the itch to provide relief in as little as 4 hours. woof and apoquel is safe without many of the side effects associated with the use of steroids. apoquel is for the control of itch associated with allergic dermatitis and the control of atopic dermatitis in dogs. do not use apoquel in dogs less than 12 months old or those with serious infections. apoquel may increase the chance of developing serious infections and may cause existing parasitic skin infestations or pre-existing cancers to worsen. do not use in breeding, pregnant, or lactating dogs. most common side effects are vomiting and diarrhea. don't wait. ask your veterinarian about apoquel today. apoquel. it's itch relief worth barking about. bark but climbing 58,070 steps a year can be hard on her feet, knees, and lower back. that's why she wears dr. scholl's orthotics. they're clinically proven to relieve pain and give you the comfort to move more. dr. scholl's, born to move.

with advil liqui-gels, what bad shoulder? what headache? advil is relief that's fast strength that lasts you'll ask... what pain? with advil liqui-gels happiness is powerful flea and tick protection from nexgard. nexgard kills both fleas and ticks all month long. and it comes in an easy-to-give tasty chew. so you'll be happy you're keeping your dog protected with nexgard. no wonder it's the number one choice of vets for their dogs and yours. see your veterinarian for more information on flea and tick protection you and your dog will love. nexgard. the vet's #1 choice.

>> 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. >> 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.

the first survivor of alzheimer's disease is out there. and the alzheimer's association is going to make it happen. but we won't get there without you.

visit alz.org to join the fight. gives skin the moisture it needs and keeps it there longer with lock-in moisture technology skin is petal smooth after all, a cleanser's just a cleanser unless it's olay.

>> 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. >> 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. >> reporter: does anything come up at that point? >> 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. >> reporter: but cops are funny, they don't just take people's words for things. they check them out. >> coming up, a new suspect, close to debra but who barely knew melissa. so why would he want to kill her? >> when "dateline" continues. i'm dara brown. sorry, are you gonna... (harmonica interrupts) everytime.

geico. 15 minutes could save you 15% or more on car insurance. ♪ protect your pet with the #1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years. i'm and i'm an emt.erer when i get a migraine at work, it's debilitating. if i call out with a migraine, that's one less ambulance to serve a community. i just don't want to let these people down. excedrin migraine. relief that works as hard as you do.

i'm dara brown. nbc reports president trump's son-in-law failed to disclose to federal investigations russian attempts to contact the trump campaign.

now back to "dateline." 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. >> reporter: detectives searched tony's house, his car and his train, but never did find melissa's phone. 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. >> 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? >> 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. >> 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. 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. >> reporter: debra villegas' world had been turned upside

down. neurologic disorders. the most common side effects are vomiting, diarrhea, and lethargy. say goodbye to ticks and fleas... with monthly simparica chewables. ...the only eye drop... ...approved for the signs... ...and symptoms of dry eye. because dry eye can mean... ...more than... ...just dryness. xiidra may provide lasting relief... ...starting in two weeks. one drop in each eye, twice a day. don't use if you are allergic to xiidra. common side effects include eye irritation, discomfort or blurred vision when applied to the eye, and unusual taste sensation. don't touch container tip to your eye... ...or any surface. after using xiidra, wait 15 minutes... ...before reinserting contacts. chat with your eye doctor... ...about xiidra. copd makes it hard to breathe. so to breathe better, i go with anoro. ♪ go your own way copd tries to say, "go this way."

i say, "i'll go my own way, with anoro." ♪ go your own way once-daily anoro contains two medicines called bronchodilators that work together to significantly improve lung function all day and all night. anoro is not for asthma. it contains a type of medicine that increases risk of death in people with asthma. the risk is unknown in copd. anoro won't replace rescue inhalers for sudden symptoms and should not be used more than once a day. tell your doctor if you have a heart condition, high blood pressure, glaucoma, prostate, bladder, or urinary problems. these may worsen with anoro. call your doctor if you have worsened breathing, chest pain, mouth or tongue swelling, problems urinating, vision changes, or eye pain while taking anoro. ask your doctor about anoro. ♪ go your own way get your first prescription free at anoro.com.

get your first prescription free withwhat sore back?sk... what bum knee? advil is relief that's fast strength that lasts you'll ask... what pain? with advil ♪ protect your pet with the #1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years.

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. >> 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? 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. she pleaded guilty to money laundering and the judge came down hard. and you went away to federal prison? >> 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? but this had a twist to it. >> when "dateline" continues.

deborah testified that tony became angry with melissa because she had 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 deborah, he killed her best friend. >> you have these domestic homicides all the time but this had a twist to it. he didn't kill deborah. >> reporter: then tony and deborah's 23-year-old son, calleb, 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 believe it was melissa's fault. >> he believed she had a part in it. >> was he mad at melissa about this? >> he was mad about the whole situation. >> reporter: and one more thing. tests showed tony's dna on melis melissa's jacket. >> the odds of finding an unrelated individual with that profile were rarer than 1 in 30 billion. >> reporter: the defense had been dealt a poor hand to play. but attorney bruce fellcher chipped away at each member. the defense said he had 250,000 reasons to make his story up. >> there was a reward offered. >> yes. >> and who offered that reward? >> scott rothstein.

>> how much was the reward in the case? >> $250,000. >> reporter: he never got the reward. the collapse of rothstein's ponzi scheme ended that. and how about the motive? it was as thin as nonsensical. >> you would think if you were so enraged that your wife were doing this, you would want to harm her and not someone else. >> reporter: as for deborah viagas, the defense attorney prize e surprised everyone when he didn't ask her a question. but he asked calleb how long he sat on that story. >> you didn't tell your mother when you first heard about that. >> no. i didn't see relevance. >> when you spent time with him, things were good? >> yes. >> okay. you love your dad? >> yes. >> reporter: would jurors notice the tear rolling down tony's cheek? on to the scientific evidence, the cell phone first.

lawyer fletcher found a mistake in the chart that was used. was the expert analysis sloppy? >> if you're a hot-shot expert, how does this error creep in. >> 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 with the police lab was a of rothstein's connections. attorney fletcher suggested there could have been cross-contamination to tip the scale. >> our goal was to educate the jury on the rothstein connections and the rothstein influence. >> reporter: had meddled with the physical evidence. contaminated, maybe? >> we can only speculate. but when a man is as powerful a guy as rothstein was, people would think they could do things. they could conjure up dna. >> reporter: and use it to frame tony viagas.

before the defense rested, they asked if he wanted to testify. >> do you wish to testify or remain silent? >> silent, sir. >> reporter: all of the evidence pointed to tony. the pepper spray, cell phone records and the dna. >> there's 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 phone records and dna results could be manipulated. >> the pieces of the puzzle do not fall into place. reasonable doubt prevents them from falling into place. >> reporter: the jury now had the case. outside the courtroom, deborah viagas saw melissa's family for the fist time in eight years. >> all these years later and it washed over me like it just happened. that i had caused these people the kind of pain that's unimaginable. >> reporter: later that

afternoon, the jury sent out a note, verdict. as the verdict was read, deborah sat with melissa's family, consoling her niece. >> tony viagas is guilty in the first degree. >> reporter: tony's face was blank. before sentencing, melissa's aunt 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. >> spend the rest of your life in a florida state prison. >> reporter: as tony was led out of the courtroom, melissa's family went to her family and hugged. >> my heart broke for them. it's a legacy for their family. >> reporter: melissa's own legacy, is the garden of reflection. before her murder, she had raised money to build it. now, her name is inscribed there, too. the victim, as prosecutors told it, in the end had nothing to do

about knowing too much about a scandal, but a victim simply of an all-consuming jealousy. that's all for this edition of "dateline." i'm craig mel vinvin. thank you for watching. i'm craig melvin. >>morales. >> this is "dateline." >> our hearts break for this mother. people don't randomly disappear. >> she was a design original. christina, the fashionista. >> the most fantastic wardrobe. >> it was news nationwide when she vanished. >> she went out to drinks with friends. never came home. >> i said, something's wrong. >> we realized, this is real. >> who was the last to see her? >> i don't know where she went. >> and where was her boyfriend?