i had always wanted since i kid, i'd see these older couples dancing. every step was perfect and every move was in unison. they were one. >> richelle shetina was looking for the perfect partner in dance and in life, and she thought she found him in a wealthy doctor. >> he was a wonderful dancer, and he introduced himself to me. my >> reporter: but somebody else wanted to cut in. this plastic surgeon. >> hello.

>> 911, what's your emergency?ee people trapped in what would become a dance of death. >> there's a bullet. i need somebody to hurry. >> there are police cars everywhere. there's crime scene tape all around.olute chaos. >> it was an in and out job, a hit to kill this person specifically. >> reporter: tonight only on "20/20," the woman caught in the two doctors. >> the kind of plot you expect from a soap opera. >> this is the oldest story in the book. this is vengeance. this is revenge. this is pride.us game of cat and mouse. >> accused of hiring a hit man -- >> so there was some kind of a triangle things going on. >> reporter: but who's the cat?is right. >> reporter: who's the mouse? >> this is a huge whodunit. >> reporter: a case with no shortage of suspects. a list of ex-girlfriends.n the back yard. and a con man with his own obsession. >> i'm kind of a sassy smart [ bleep ] and we just kind of

villainous even their own children turn on them. >> you made yourself a monster, dad. >> the verdict is in. >> unanimous verdict. >> what was yourinto that first trial? >> let's go get these guys. >> there are real sociopaths. sometimes they sleep in your bed with you. >> okay, game on.ance in texas. good evening. i'm david muir. >> and i'm elizabeth vargas. and tonight a love triangle that started in texas and went onl headlines. two doctors and a beautiful woman who says she finally found the love of her life. >> but right here tonight what you have never heard until now.the center now speaking out. ryan smith with a story that went from dance lessons to dirty tricks to deadly consequences. a lazy summer afternoon in lubbock, texas -- >> 911, what's the emergency? >> reporter: a break-in in this neighborhood of stately homes.

not show up for work today. >> reporter: prominent local physician dr. joseph sonnier is found murdered. a landscaper finds his oh, no! oh, god. >> ma'am, ma'am. what's going on? >> reporter: shot and stabbed multiple times. >> there's a bullet that wasground. i need somebody to hurry. >> yes, ma'am. >> reporter: zach johnson, a detective with the lubbock police, heads to the scene. this neighborhood had to bey this killing. >> they were. they were very scared because this doesn't happen. especially to somebody that's soeporter: upon entering sonnier's house it's immediately clear to detective johnson that this isn't a robbery gone bad. >> there was artwork in the very expensive pieces of furniture. there was ipads, all kinds of things, just kind of laying around. you know. nothing was taken. it was an in and out in the dining area

>> and the crime scene was very succinct. it wasn't spread out. you had the overturned chair. you hadn the floor. and you had the casings. so you knew that he was shot right here. >> reporter: another clue stands out.s on the floor near the shell casings from the bullets. police determine it's a crudely fashioned silencer. >> we were dealing with something that was a hit of ebody had come to this house to kill this person specifically. >> reporter: but who? >> to me it was just know, why is this man dead? he's a well-respected citizen in this community. why is he dead? >> reporter: sonnier's children are devastated and perplexed.er their mother had been murdered. and now their father too. for sonnier's oldest son, dallas, it's a scenario. >> i knew how to plan a funeral. i knew how to scrub blood off

i knew everything we had to do done it once before. >> this just doesn't happen. >> the statistical likelihood that both parents would be occasions, is unfathomable. i got the call the day before the two-year anniversary of my mother's death. i thought maybe it had something to do with herow out of left field and completely out of nowhere this was. >> reporter: for joseph's third son, ph questions than answers. >> we started racking our brains, well, it's got to be some kind of girlfriend situation. if it's not a robbery, it's somebody he knows.s all took place in lubbock, texas. nestled in the heart of ranching country. a broad and wind-swept terrain of cotton fields, cattle, and you can't see better sunsets and sunrises and thunderstorms

but it's the people that drive it. there's no probably anywhere in the world. >> reporter: one of those people is the victim, joseph sonnier, a well-known doctor, successful businessman, and and as far as women in lubbock are concerned, unquestionably a catch. he enjoys foreign travel, has a six-figure wine collection, and even makes his own he was a single man in his late 40s with disposable income and an empty house. >> he's living the single life and having a fun time. 't about getting married? >> i don't think he would have gotten married again. >> reporter: at 19 sonnier married his high school sweetheart, becky.is happy childhood, with loving parents. >> merry christmas, dad. >> my dad was the most supportive person in my life. my mom was our emotional>> merry christmas.

>> he was the one who was going to push us to succeed, push our dreams. >> reporter: dallas remembers how his father fell apart when his mother walked out on him after 27 years of marriage for another man. >> she was that he had ever been with and ever dated and ever fallen in love with. when they got divorced, it was a shock to him. everything he'd worked for in his life evaporated in one>> reporter: his ex-wife, becky, quickly remarried, and to the sonnier family's horror she was murdered by her new husband, who james sonnier remembers how his father helped him and his brothers come to terms with their mother's murder. >> he came in aftered and he became like our guide about how to handle this -- this tragedy. >> reporter: and the elder sonnier was still in the process

scene, dr. sonnier takes a chance. >> he went i think on a larce class. ballroom and salsa. swing. and through that dance community he finds. >> he started to meet beautiful single women, attractive women who were also in his age range. >> so able to start dating again. >> and he got the mojo back like that. >> so how did you feel about the women that he dated? >> the truth is we liked most of them.nd his brothers had grown up and moved away. but every fall they joined their dad for a texas tech football game. one year dr. sonnier brings a family tailgate. >> she's blond. she's tall. she's gorgeous. >> reporter: she is richelle shetina. single mother of four boys who a ballroom dance class.

which is -- that's nerve-wracking for some people. me. i certainly wasn't nervous about it. >> she knew how to handle herself in a social situation, around his sons. we're toughknow. and we gave her a thumbs up. >> reporter: like sonnier, richelle is divorced and has grown children. they begin dating. and when things start to get her to visit his grandchildren in los angeles. >> touch your head. >> we had a great time. she came over to the house. played with my kids.e better. >> she's a smart girl. >> reporter: while sonnier is enjoying dating richelle, dallas says his father's feelings do not run >> in your mind he was never going to put a ring on it. >> reporter: but richelle may want more than casual dating. according to sonnier's family she repeatedly tells him how much she wants to get married. every step of the way following

>> that's not true. what i was looking for was a with a good person. and that was it. >> reporter: a couple of months after the l.a. trip dr. sonnier tells his son that heere going to paris. >> it was a birthday gift for my 50th birthday. i was just over the moon. it was really a dream come true. >> reporter: joseph and richelle's romantices a trip to the pont pont des artes, a bridge across the seine the thousands. >> we bought a lock and joseph wrote his name on it and i wrote my name on it, and you throw the keen into the seinet locks the most forever. >> reporter: but for richelle and joseph forever would only be a matter of weeks. on a sweltering wednesdaylle learns that the love of her life has been

>> there are police cars everywhere.e all around joseph's house. emergency vehicles there. reporters there.olute chaos. >> reporter: searching for a killer, the first place police go is to the people closest to the victim. so detective zach johnson's attention turns to sonnier'sichelle shetina. >> meeting with richelle that very first time i don't know a lot about her. >> did you ever have a time where you suspected that richelle could in some way haven dr. sonnier's death? >> you always have to consider people the closest because 90% of the time it's going to be the people that are victims that committed crime against them. >> reporter: the police take richelle in for questioning. she's on the hot seat, and she starts naming names. >> there's just, you s that he dated. and joseph would get these

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"20/20" continues with "a last dance in texas." joseph sonnier, a respected doctor, is found murdered in his home in an upscale lubbock . and the first person homicide detective zach johnson wants to

sonnier's current girlfriend. he brings her ing. >> how would you describe your relationship with dr. sonnier? >> he's -- he's the love of my life. >> meeting with first time, i don't know a lot about her. there were a couple of things that were mentioned by her that struck me as odd. >> reporter: richelle tells detective johnson that in up to the murder she feels like someone was watching her, following her to the gym. >> i had gone in to work out and i pulled into the parking lot and there was this big -looking guy sitting there. and at the door, like he was someone. >> reporter: she also thinks someone was hiding in sonnier's back yard,e one evening after dance class. >> it was dark outside, and joseph and i both saw a flash from thend kind of joked about, you know, maybe somebody was following us.

asks richelle if she knows anyone who might have stalked the doctor or held a grudge against him.ould get this -- these horrible text messages, you know, calling him a [ bleep ] and you know, you're such a [ bleep ] and whatever. as no suspects. she rattles off a list of sonnier's ex-girlfriends. she also remembers a letter she mysterious woman named tina. >> and that she met joseph on the internet and that they had sex for money, d he said, you know, this is obviously someone trying to drive a wedge in between us. >> reporter: police are intrigued by the idea of a love ad of focusing on sonnier's dating history he asks richelle about her past lovers. one name is on the tip of >> his name is thomas michael dixon. he's a plastic surgeon in amarillo.

>> hello. i'm dr. mike dixon. if you're considering -- >> reporter: well known, he's divorced, wealthy, and used to date richelle. >> he had a place int there to get botox injections. >> what attracted you to him? >> he was funny, he was very witty, and he was enjoyable. if it can be enjoyable put needles in your face, you know, i guess that's about as enjoyable as it could be. >> reporter: richelle and dr. dixon had dated for a yeary broke up and she started seeing dr. sonnier. >> did he know about your current relationship? >> he knew that i was dating joseph. he called him by namees of text messages, trying to get me to go out with him and to meet him for coffee. >> reporter: richelle says she rejected his advances but he waso he wanted you to see him on the side, basically?

i told him no. is dixon the kind of man to take no for an answer? johnson wants to find out. so he drives two for a face-to-face conversation with richelle's ex that the detective secretly records. [ knocking ] >> dr. dixon, i'mson with the lubbock police department. we've got a case down in lubbock, and i'm needing to talk to you about it. >> i told him, it's richelle's boyfriend.as oh, i don't know anything about him. >> i don't know anything about him. i haven't talked to her in months and months. >> and i was like, okay, well, that's a in our interview with richelle she told us that he knew about the relationship. >> yeah, i'll be honest with you. i loved, loved, loved that did. richelle. over this break-up. he just couldn't seem to let her go.

>> i really had fallen head over heels. in fact, made a lot of life changes for her. >> he's very up front about yeah, i wanted her back.on recalls how their relationship ended when he failed to propose to richelle on her birthday and instead gave her a subscription to a tea >> and she went ballistic and said, well, it -- i mean i remember clearly it's not a big [ bleep ] rock. and i said, no, it's ng ring. it was tea. tea is lovely. i don't happen to drink it. he was not present in anyive aspect of my world. >> reporter: but despite richelle's unhappiness with him dixon says they kept in contact after their break-up, exchanging texts and he says they weekend getaway to a resort. >> she was like, hey, do you want to put this back together? and i was like, yeah, i do. and so blah, blah, blah. the next day she's like, hey,

>> he still loves her. he's got a lot of feelings for her. but boom, on him and says oh, by the way, i'm in love with my dance partner. >> some would say, well, you're throwing it in his face a littleno, i wasn't throwing it in his face. there was an ugliness from him to me. >> reporter: dixon seems like a likely suspect, but he has an sonnier's murder. as do richelle shetina and those ex-girlfriends. detective johnson is stumped. >> there's something not right here. this is a huge r: until johnson gets the call all detectives pray for. it's from a tipster who offers a new name that could crack the case. >> his name's dave shepard. >> reporter: but who is dave shepard? stay with us. , stephanie. we're, like, so goth. we're, like, goth goth. honey? i'm dying my hair, mom. hair dye? no, not in my bathroom!

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tt4w`t2n`qt"" dztq sy@ tt4w`t2n`qt"" entq #] tt4w`t2n`qt"" gzt& :zx 4 tt4w`t2n`qt"" iztq @=l tt4w`t2n`qt"" jntq rm, er: "20/20" continues with ryan smith and "a last dance in texas."tive zach johnson is desperately trying to unravel a tangled web, but he has no viable suspects in the murder of dr. joseph sonnier. a phone call. what was it that broke this case wide open for you? >> when paul reynolds called the

i'm trying to get some information and we think we've got a crime that happened down here in lubbock. >> who is paul reynolds? >> believe it or not, there are good people in the world and paul reynolds is one of them. >> reporter: reynolds is a registered nurse. down on his luck when ad named dave shepard offers to let him crash on his couch. he offers to tell police everything he knows. >> so i crashed on his couch. he kind of started weird talk. >> reporter: according to reynolds, shepard starts acting strangely, telling wild violent stories of killing a man in credulous, reynolds googles the information, only to discover that the murder is real. >> and then these stories started to come out. tells investigators that coincidentally, shepard is a good friend of none other than richelle's ex, dr. mike dixon. the investigation takes a roing in on shepard.

relationship, how it evolved. >> he's afd of a sassy smart [ bleep ] and we just hit it off. >> they bonded over cigars and martinis at local hangouts in amarillo commiserating over ex-wives.s is a very sociable thing and we just connected, hooked up. >> so y'all just happened to >> that's it. and kind of had a co shepard's daughters, haley, abigail, and rachel speaking exclusively to "20/20" about the strange bond between their father and dr. mike definitely obsessed with mike. >> really? >> he had a big man crush on mike. >> reporter: it was an unlikely bromance.ful plastic surgeon, and shepard, a divorced unemployed con man. >> so what did your dad see in >> his money. and his success. >> dadke. >> reporter: shepard may have

dixon was obsessed with someone else. richelle eft his wife for her. you know, she broke up his marriage. and he just wanted i guess payback. >> david and tells us exactly what happened. >> so he tells you everything. >> this whole thing was like this stair step, and it started at the very bottom of these stairs as being a reporter: shepard tells police that it all began harmlessly enough, trying to tarnish dr. sonnier's reputation in the hope that richelle would break up with him andhe arms of dixon. what were some of the things they came up with? >> they were going to get this porn subscription, like child gay important, and they were going to send it to dr. office. >> go to an adult bookstore and buy the most obscene, nastiest,

and send it to his office. because -- i said that's a gift that'll keep giving. >> they were thinking that was going to ruin hishis professional reputation. >> reporter: thinking more like teenagers than grown men, they concoct ridiculous schemes to humiliate dixon's rival, like hiring a stripper to pretend to be sonnier's richelle will think he's two-timing her. as the months go by and richelle is still dating sonnier, dixon becomes desperatve to follow him. we have to figure out where he's at. he goes, hey, what are you doing? let's go -- let's take a little trip to lubbock. >> reporter: they drive the 120-mile stretch of highwaynd lubbock. >> and next thing i know he tells me that richelle and dr. sonnier take these dance d he showed me where the dance class was, where to go. >> reporter: shepard spends months in lubbock, watching the lovers. turns out it was shepard whothe early morning hours when he's staking out her gym.

move breaks into sonnier's back yard andl selfie. the flash alerting richelle and sonnier inside. >> it looked like a camera flash. and we kind of shrugged our shoulders and said that was eporter: shepard fails to dig up dirt on sonnier. so dixon grows impatient. >> was there a specific act that he was wanting done that -- wasll were discussing? >> yes. >> and what was that? >> he -- he wanted him hurt. and then it gradually developed into having him killed. hours of interrogation an exhausted shepard gives police a blow by blow of what happened that night. a full confession. july 10th, 2012night shepard will stalk his prey. he breaks into sonnier's back yard armed with a gun in wait. sonnier comes home, makes himself a drink after a long day at work.

>> i pull the gun out of the bag on it. i point the weapon with the bottle at him. >> reporter: shepard pushes through the window and fires, emptying his gun into sonnier.ehow finds enough strength to stumble out of the room to get away. but shepard is in pursuit and finds him in the garage, where he stabs him 11 times.e's laying on the floor, not moving, not breathing, nothing. i check his pulse in his neck. >> reporter: there's so much blood it seeps under the garage door to the outside. >> he's a murderer. he's a liar. he's a thief. he's an ots of things. as far as his role in this, i think he was a pawn for mike dixon.ict attorney matt powell offers

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re of "20/20" and "a last dance in texas." despite rolling across the outer western plains, in downtown lubbock things were heating up as the biggest murder trial this town

>> this prominent plastic>> dr. michael dixon -- >> accused of hiring a hit man. >> friend and business partner david shepard. >> i cannot believe that they did this. it makes me so angry. a lowlife scum [ bleep ] doctor. >> reporter: when dr. mike dixon was arrest kd and brought to trial for his role in joseph sonnier's death, dallaslbent on bringing his justice. >> what was your mindset going into that first trial? guys. >> reporter: but as always, there's another side to this was another son in that courtroom. >> he was a good dad. he still is a good dad. >> reporter: andrew dixon convinced his father is y're trying to prove him guilty, and he's fighting for his life. i mean, it's just terrifying and just so sickening. >> reporter: the man tasked with putting andrew away, a hard-charging texas district attorney named matt powell. >> mike dixon's running the show

>> many people make thee dixon never laid a hand on dr. sonnier. >> he's just controlling the -- dave shepard's just another instrument for mike dixon.hat instrument dave shepard has agreed to testify. pitted against his friend mike dixon to avoid the death penalty. >> this is the oldest story in the book. this is vengeance. this is revenge. >> reporter: the motive? in courtroom 72 of the lubbock county courthouse the prosecution paints a picture for the jury of dixon as anulating puppetmaster. >> he wanted her to suffer or he wanted her back. he knows what the true answer to that question is. but dr. sonnier was in the way. >> reporter: the pillars of e -- police find the gun shepard used at the bottom of a lake, conveniently located behind dixon's office. and discover it's registered to dixon's brother. and theynce videos from the day after the murder. that's shepard in the plaid

the two hanging out.s. >> was there any discussion about when the police went over there and spoke to him? >> he was nervous. he said i had to get out of town. >> reporter: but he didn't.ttempts suicide. he slits his wrists. when he fails, who does he call for help? his buddy mike. here they are. that's shepard towering overd into the doctor's office to stitch shepard up. >> so he sews your hand up. does he discuss anything with you in >> he told me i need to keep my cool. >> reporter: prosecutors also have a myriad of incriminating text messages between shepard and dixon. as shepard stalks sonnier for months.m dixon ordering shepard, you have to stay close, watch him in the a.m., go get 'em. and put it on him. the price for murder between friends? police say dixon paid shepard for the hit in the form of a box

bars that turned up at this pawn shop in before the murder, two the day after the murder. sold by none other than dave shepard. >> in terms of demeanor hene way or the other, it sounds like? >> not at all. >> couple days later he's on the front page of the paper. >> i was blown away. >> reporter: but dixon's lawyers have an explanation for all of this.used. dixon's home. defense attorney frank sellers shows me where. >> they came in here. they're picking out a cigar to shepard opens this drawer here, and it's a gun. >> so that's how shepard knew a gun was in that drawer. >> exactly. >> reporter: and the silver bars? were for a business investment, not a murder for hire. they say dixon only wanted shepard to try to take photographs of sonnier out with other women to sonnier wasn't all he was cracked up to be. >> in the days before they leave for paris he says, "it's got to happen tomorrow because the trip is imminent."

trying to say somebody imminently. >> we believe it was an attempt to make the trip uncomfortable. get the photographs. >> reporter: and they say this was all because dixon was elieved richelle was his face. >> richelle was posting on facebook all the time how dr. sonnier wasat michael dixon would ever be. and he wanted to show richelle that she was wrong. >> reporter: zbl so from your perspective it wasn't shetina. ego. >> right. if he was obsessed with her, he'd have been following her. >> were you in any way trying to flaunt your relationship?ed from my facebook page. so was i flaunting anything? no. >> reporter: dixon's attorneys say dave shepard simply went rogue when he killed sonnier. >> do you at least admit that he seed by even discussing this relationship? murder? no.

>> mike is morallyid shepard being down here. but not for the purpose of killing dr. sonnier. mike dixon never wanted that >> i asked him, you sure you want to do this, mike? i said, when you kill ffect you for the rest of your life. you'll have nightmares. it will bother you. and he goes, "doesn't bother me." >> reporter: and the trigger man to testify against his best buddy in open court, the sonnier family was sitting front and center. >> he had a chance to get uponfirm his story, point to that guy as the person who paid him to kill my dad, and end it all. >> reporter: he does end it. but not in the way dallas wants.ut to drop a bombshell. >> but daddy, why didn't you tell that?

flesh and blood despise him.rself a monster, dad. >> reporter: when we come back. i'm jerry bell the second. and i'm jerry bell the third. i'm like a big bear and he's my little cub. this little guy is non-stop.g out with his friends. you've got to be prepared to sit at the edge of your seat and be ready to get up. there's no "deep couch sitting." definitely not good for my back. really don't like right here. (doorbell) what's that? a package! it's a swiffer wetjet. it almost feels like it's moving itself. this is kind of fun. floor? eww! this is deep couch sitting. [jerry bell iii] deep couch sitting! performance... style... ...reinvented. sophistication... introducing the all-new lexus rx and rx hybrid. agile handling. available 12.3-inch navigation screenss roof. never has luxury been this expressive.

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>> announcer: "20/20" continues with> when the convicted murderer dave shepard took the stand at his best friend mike dixon's trial, he was facing the victim's family, the jury,ost poignantly his three daughters, rachel, abigail, and haley. and they are not here to defend their father. >> you were in that closure. >> we were there more in support of the sonnier family. >> right. >> yes. >> our heart was broken for them.

saying their father is a >> and do you think that mike dixon paid your father to kill dr. sonnier? >> yes. >> yes. >> reporter: but on the stand ay saw coming. >> shepard himself has basically denied all of his previous testimony. >> reporter: shepard's confession was expected to put mike dixon away. this is what he said, well, just go behind him when he's not paying attention, hit him with a board. i said, you could probably kill him. and doc went -- like that. that later. >> reporter: but in the courtroom he suddenly changes his story and says mike dixon never asked him to kill sonnier, letting his friend hook. >> you begin to question him. what happens? >> well, he completely digressed from what his statement was to law enforcement in the fact thate any involvement in this deal. >> reporter: the veteran prosecutor blindsided. >> what's going through your mind? >> okay, game on. >> in that hated anyone more than i've

>> reporter: the shepard daughters also watching are embarrassed and ashamed. >> it was cowardly. >> i mean, he has a chance to right and he completely ruined it. >> why do you think he did that? >> he was trying to help out his buddy.irls compelled they apologized to the sonnier family for what their father has done. >> what did you say to them? >> we are so sorry for what he has done continuing to do to you. >> reporter: and after shepard changes his story, back in jail, his daughters confront him. it's a rare and raw look at a ly. >> but daddy, you didn't tell the truth. >> i did. >> you didn't say anything. you just kept saying that you wouldn't tell them. >> but i did. >> why, you didn't, daddy. you said i plead the fifth. i don't -- i'm not going to answer that. >> none of this is right.

>> no matter what i do -- they think i'm some kind of a monster. >> you've made yourself a monster, dad. literally breaking down in tears. >> it was frustrating. i felt like i was scolding a child. like i just want you to answer my question and then you can go back to time out. >> reporter: but the damage was done. to free his friend, it works. the case ends in a mistrial. >> the only reason for the hung jury was david shepard's ter: regardless, d.a. matt powell is undeterred. >> matt powell comes into the room where we're standing, and without blinking he says, "we are going to get thisng to do this again. don't you worry. i've got you." and that's all i needed to he second trial is scheduled, delaying a homecoming for andrew dixon's father, who once lived in this big texas spread with a canyon as his backou look so happy.

he did dad things. you know, american dream kind of stuff. >> reporter: but that dream was re truth is andrew's father is facing capital murder charges and the second trial begins. >> amarillo doctor michael dixon is back onter: and this time around prosecutor mike powell has a new witness. >> the number one most important thing from this second trial was the rageous testimony of haley shepard. >> reporter: next, dave shepard's own daughter haley takes the stand. and what she recalls about a ill stick a fork in this case once and for all.

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>> announcer: "20/20" continues with "a last dance in texas." lubbock, texas. haley shepard, the hit man's the stand. she takes the jury back three years. and you'll see why. it's a hot summer night in amarillo, texas.e shepard, treats his daughters to a fancy steak dinner, served with a side of suspicion. >> he had some money. i got a nice shepard's daughters say that night their typically cash-poor father bragged about buying a new grill and new tires for his suv. >> dad had money out of the ust randomly had money. and he didn't ever have money. >> reporter: for his older daughter haley there was also a brand new cell phone. >> we all asked him, how do you have money? and"i did some

early." >> reporter: this time the prosecutor calls her, not her mike dixon's retrial. and you think that was a prepayment for killing dr. sonnier. >> in retrospect, absolutely.m joseph sonnier's family haley's testimony is a game changer. >> she got up there and said, at dinner i asked my dad, i saids money? and david shepard says to her, i did some work for mike, he paid me early, don't ask what i did for him. over. >> reporter: it takes a new jury only three hours to deliberate. >> and my hand was shaking like this because i knew we got a i knew it. i knew it. i knew it. >> reporter: and he's right. >> the verdict is in. >> unanimous verdict. >> guilty on two charges. >> reporter: mike dixon iswo counts of capital murder.

>> i had to turn to my wife, and i had to say, he said guilty, right? he saideen waiting for that moment for over three years. >> reporter: for the sonnier brothers it's finally look at the photos of him, smug smile. when you look at his mug shot from his arrest, smug smile. and he smile for both trials, and it was so great to be able to know that we'd finally wiped that smile off hisr: still -- >> he's lost everything. time with his family. >> reporter: another son, andrew dixon, remains convinced his father is innocent.ut the fact that he has to spend the rest of his life in prison without parole, how does that make you feel? >> it's a nightmare. you lay your head down at night and it's just always there.

everything. >> reporter: remarkably, dave ave accepted both men's fate as justice served. >> i know you guys don't talk to your dad a lot right now. but if you could what would you say to him? >> we're doing very good. okay. >> we're okay without him. >> i think he's where he needs to be. >> reporter: as for the woman at the center of it all, richelle shetina has a warning.eal sociopaths and psychopaths that walk amongst us. they're charming. they sit at the dinner table with you and your children.hey sleep in your bed with you. they're not capable of feeling love for you or empathy for anyone. when you see that, don't ignore get out. run. as fast as you can. >> reporter: tonight, richelle

of her mind but sayssonnier will always have a place in her heart. >> i would tell him i loved him.ays -- i'll always love him. and i would just tell him how sorry i am.hepard and his one-time best friend dr. mike dixon are now serving life in prison without the possibility of parole.ppealing that verdict. >> and that is our program for tonight. but be sure to join us tomorrow night for a special "20/20" saturday. i'll have the very latest on thee bill cosby case. i'm elizabeth vargas. >> and i'm david muir. for all of us here at "20/20" and abc news, thank you for watching tonight. and i'll see that's right.