they were one. >> richelle shetina was looking for the perfect partner in dance and in life, and she thought she found him in a weahy doctor. >> he was a wonderful dancer, and he introduced himself to me. my name's joseph. >> reporter: but somebody else waed to cut in. this plastic surgeon. >> hello. i'm dr. mike dixon. >> 911, what's your emergency? >> reporter: three people trped 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. it was just absolute 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 middle between 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. >> reporter: a dangerous game of cat and mouse. >> accused of hiring a hit

>> so there was some kind of a triangle things going on. >> r reporter:ut who's the cat? >> no part of this is right. >> reporter: who's the mouse? >> this is a huge whodunit. >>eporter: a case with no shorge of suspects. a list of ex-girlfriends. a peeping tom in n the back yard. and a con man with his own obsession. >> i'm kd of a sassy smart [ bleep ] and we just kindd of hit it off. >> reporter: characters so villainous even their own children turn on them. >> you made yourself a monster, dad. >> the verdict is in. >> unanimous verdict. >> what was your mindset going into that first trial? >> let's go get these guys. >> there are real sociopaths. sometimes they sleep in your bed with you. >> okay, game on. >> reporter: a last dance in texas. good evening. i'm david mu. >> and i'm elizabeth vargas. and tonight a love triangle that started in tex and went on to make national headlines. two doctors and a beautiful woman who says she finally found the love of her life. >> but right here tonight what

that woman caught in the center now speaking out. ryan smith with a story that went from dance lessons to dirty tricks to deadly consequences. >> rorter: on a lazy summer afternoon in lubbock, texas -- >> 911, what's the emergency? >> reporter: a brereak-in i i this neighborhood of stately homes. >> somebody has bken a window not show up for work today. >> reporter: prominent local physician dr. joseph sonnier is found murdered. a landscaper finds his body. >> oh, no! oh, god. >> ma'am, ma'am. what's going on? >> reporter: shot and stabbed multiple times. >> there's a bullet that was laying on the ground. 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 be freaked out by this killing. >> they were. they were very scared because

especially to somebody that's so esteemed. >> reporter: upon entering soier's house it's immmmediately clear to detective johnsonon that this isn't a robbery gone bad. >> there was artwork in the home. there were 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 job. >> reporter: in the dining area johnson can see where the fatal blows were delivered. >> and the crime scene was very succinct. it wasn't spread out. you had the overturned chair. you had the glass on the floor. and you had the casings. so you knew that he was shot right here. >> reporter: another clue stands out. a gatorade bottle lies on the floor near the shell casings from the bullets. police determine is a crudely fashioned silenc. >> we were dealing with something that was a hit of sorts, that somebody had come to this house to kill this person specifically. >> reporter: but who?

you 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. two years earlier their mother had been murdered. and now their father too. for sonnier's oldest son, llas, it's a hauntingly familiar scenario. >> i knew how to plan a funeral. i knew how to scrub blood off the floor. i i knew evething we had to do because i'd already done it once before. >> this just doesn't happen. >> the statistical likelihood that both parents would be 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 her death. completely out of nowhere this was. >> reporter: for joseph's third son, phillip, there are more

brains, well, it's got to be some kind of girlfriend situation. if it's not a robbery, it's somebody he knows. >> reporter: this all took place in lubbock, tes. nestled in the heart of ranching country. a broad and wind-swept terrain money. >> you can't see betterunsets and sunrises and thunderstorms and everything else coming in. but it's the people that drive it. there's no better people probably anywhere in the world. >> reporter: o one of tse people is the victim, joseph sonnier, a well-known ctor, successful businessman, and multimillionaire. 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 perfume. >> 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.

married? >> i don't think he would have gotten married again. >> reporter: at 19 sonnier married his high school sweetheart, becky. dallas recalls his happy childhood, with loving parents. >> merry christmas, dad. >> my dad was the most supportive person in my life. my mom was our emotional support. >> merry christmas. >> reporter:. >> he was the one who was going to push us to succeed, push us to follow 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 the only person 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 second. >> reporter: his ex-wife, becky, quickly remarried, and to the sonnier family's horror she was

then killed himself. mes sonnier remembers how his father helped him and his brothers come to terms with thei mother's murder. >> he came in after she was murdered and he became like our guide about how to handle this -- this tragedy. >> reporter: and the elder sonnier was still in the process of rebuilding his own life. 48 years old and on the dating scene, dr. sonnier takes a chance. >> he went i think on a lark to a dance class. ballroom and salsa. swing. and through that dance community he found his confidence again. >> reporter: and that's not all he finds. >> he started to meet beautiful single women, attractive women who were also in hisge range. >> so that's how he was able to start dating again. >> and he got the mojo back like that. >> so how did you fee about the women that he dated? >> the truth is we liked most off themem.

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 date to their f family tailgate. >> shehe's blond. she's tall. she's gorgeous. >> reporter: she is richelle shetina. single mother of four boys who sonnier meets at a ballroom dance class. >> it's the first date and he's bringing you around his family. which is -- that's nerve-wracking for some people. >> i mean, it was the first date. it really wasn't a big deal to me. i certaly wasn't nervous about it. >> she knew how to handle herself in a social situation, around his sons. we're tough critics. you know. and we gave her a thumbs up. >> reporter: like sonnier, richelle is d divorced and has grown children. they begin dating. and when things starto get serious, he takes her to visit his granhildren in los angeles. >> touch your head. >> we had a great time. she came over to the house. playeded with my kids.

>> she's a smart girl. >> rorter: while sonnier is enjoying dating richelle, dallas says his father's feelings do not run to marriage. >> in your mind he was never going to put a ring on it. >> that's right. >> reporter: but richelle may want more than casual dating. accordin to sonnier's family she repeatedly tells him how much s she wants to get married. >> it was constant pressure at ery step of the way following the l.a. trip. >> that's not true. what i was looking for was a committed relationship with a good person. and that was it. >> reporter: a couple of months after the l.a. trip dr. sonnier tells his son that he and richelle were 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 romantic getaway includes a trip to the pont pont des artes, a bridge across

>> 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 seine river. and that locks the most foforever. >> reporter: but for richelle and joseph forever would only be a matter of weeks. on aweltering wednesday in july richelle learns that the love of her life has been murdered. >> there are police cars everywhere. there's crime scene tape all around joseph's house. emergency vehicles there. reporters there. it was just absolute chaos. >> reporter: searching for a killer, the first placeolice go is to the people closest to the victim. so detective zach johnson's attention turns to sonnier's girlfriend, richelle 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 have

>> you always have to consider people the closest because 90% of the time it's going to be the people that are closest to our 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 kn, some girls that he dated. and joseph would get these horrible text messages, you know, calling him [ bleep ]. you know, you're such a [ bleep ], whatever. >> reporter: when "20/20" returns. hey, you forgot the milk! that's lactaid. right. 100% real milk, just without the lactose. so you can drink all you want... ...with no discomfort? exactly. here, try some... mm it is real milk. see? delicious. hoof bump!p! oh. right here girl, boom lactaid . 100% real milk. no discomfort and for a creamy and delicious treat, try lactaid ice cream

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>> announcer: "20/20" continues with "a last dance in tes." joseph sonnier, a respected doctor, is found murdered in his neighborhood. and the first person homicide detective zach johnson wants to interview is richelle shetina, sonnier's current girlfriend. questioning. >> how would you describe your relationship with dr. sonnier? >> he's -- he's the lovove of my life. >> meeting with richelle that very 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 inhe months leading up to the murder she feels like someone was watching her, following her to the m. >> i had gone in to work out a i pulled into the parking lot

creepy-looking guy sitting there. and at the door, like hehe was looking for someone or watching someone. >> reporter: she also thinks someone was hiding in sonnier's back yard, spying on the couple one evening a after dance class. >> it was dark outside, and joseph and i both saw a flash from the outside. we laughed and kind of joked about, you know, maybe somebody was following us. >> reporter: detective johnson asks richelle if she knows anyone who might have stalked the doctor or held a grudge against him. >> joseph would get this -- these horrible text messages, you know, calling him a [ bleep ] and you know, you're such a [ bleep ] and whatever. >> reporter: and richelle has no shortage of theories about suspects. she rattles o a list of sonnr's ex-girlfriends. she also remembers a letter she received from aysterious woman named tina. >> and that she met joseph on the internet and that ty had

and he said, youknow, this is obviously someone trying to drive a wedge in between us. >> reporter: police are intrigued by the idea of a love rival. but instead of focusing on sonnier's dating history he asks richelle about her past lovers. one name is on the tip of her tongue. >> his name is thomas michael dixon. he's a plastic surgeon in amarillo. >> reporter: dr. mike dixon. >> hello. i'm dr. mike dixon. if you're considering plastic surgery -- >> rorter: well known, he's divorced, wealthy, and used to date richelle. >> he had a place in amarillo and i went 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 eoyable to have somebody 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 yeaear and a half before they broke up and she started seeing dr. sonnier. >> did he know about your

>> he knew that i was dating joseph. he called him by name in a series of text messssages, ying to get me to go out with him and to meet him for coffee. >> reporter: richelle says she rejected his advances but he was persistent. >> so he wanted you to see him on the side, basically? >> he wanted me to come back to him. i told him no. >> reporter: but is dixon the kind of man to take no for an answer? johnson wants to find out. so he drives two hours to amarillo for a face-to-face conversation with richelle's ex that the detective secretly records. [ knocking ] >> dr. dixon, i'm detective johnson 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. and his first thing was oh, i don't know anything about him. >> i don't know anything about him.

>> and i was like, okay, well, that's a little odd because 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 woman. i really did. >> he was obsessed with richelle. he had a lot of problems getting over this break-up. he just couldn't seem to let her go. >> for detective zach johnson alarm bells were sounding. >> 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. >> reporter: dixon recalls how their relationship ended when he failed to propose to richelle on her rthday and instead gave her a subscription to a tea of the month club. >> and she went ballistic and said, well, it -- i mean i rememb clearly it's not a big [ bleep ] rock. and i saidid, no, it's not. like a wedding ring. >> it wasn't about the fact that it was tea. tea is lovely. i don't happen to drink it. he was not present in any

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 even planned a weekend getaway to a resort. >> she was lili, hey, do you want to put this back together? and i was like, yeah, i do. and so let's plan a trip, blah, blah, blah. the next day she's like, hey, sorry, i'm in love with my dance partne >> he still loves her. he's got a lot of feelings for her. but boom, she drops the hammer 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 little bit. >> well, no, 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 alibi t night of 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 whodunit. >> reporter: until johnson gets e call all detectives pray

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 w with us., stephahanie. 're, like, so goth. we're, like, goth goth. sfx: knocks on door. honey? i'm dying my hair, mom. hair dye? no, not in my bathroom! relax, mom. honey, just let me in! sfx: door rattling. no. tiffany! no. tiffany! it's just purple. teenage daughter? get scrubbing bubbles. kill 99.9% of germs and destroy dirt and grime. you only need scrubbing bubbles disinfecting cleaners for 100% problem solved. we work hard, so you don't have to. sc johnson, a family company. bleeding gums? you may think it's a resu of brushing too hard. it's not. it's a sign of early gum disease which you can help reverse by using listerine added to your brushing routine

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tt2w`t2n`qt" bt@q2;x tt2w`t2n`qt" "a@q"7< tt2w`t2n`qt" bm@q)> announcer: "20/20" c continues

dance in texas." homicide detective zach johnson is desperately trying to unravel a tangled web, but he has no viable suspects in the murder of dr. joseph sonnier. until he gets a phone call. what was it that broke this case wide open for you? >> when paul reynolds called the police department. >> my name is paul reynolds. i'm trying to get some information and we think we've got a crime that happened down here in lubbock. it's a homicide. >> 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 a childhood friend 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 in with just weird talk. >> reporter: according to reynolds, shepard starts acting strangely, telling wild violent stories of killing a man in

incredulous, reynolds googles the information, only to discover that the murder is real. >> and then these stotories started to come out. >> reporter: reynolds tells investigators that coincidentally, shepard is a good friend of none other than richelle's ex, dr. mike dixon. the investigation takes a turn, zeroing in on shepard. >> and tell me about y'all's relationship, how it evolved. >> he's quick-witted. i'm kind afdof aassy smart [ bleep ] and we just hit it off. >> they bonded over cigars and martinis at local hangouts in amarillo commiserating over ex-wives. >> smoking cigars is very sociable thing and we just connected, hooked up. >> so y'all just happened to meet up in the cigar shop -- >> that's it. and kind of had a connection. >> reporter: shepard's daughters, haley, abigail, and rachel speaking exclusively to "20/20" about the strange bond between their father and dr. mike dixon.

>> really? mike. >> reporter: it was an unlikely bromance. dixon, a successful plastic surgeon, and shepard, a divorced unemployed con man. >> his money. and his success. >> dadanted to be mike. >> reporter: shepard may have been o obsessedith dixon, but dixon was obsessed with someone else. richelle shetina. >> he left his wifeor her. you know, she broke up his marriage. and he just wanted i guess paybyback. >> david shepard does come in 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 prank. >> reporter: shepard tells police that it all began harmlessly enough, trying to tarnh dr. sonnier's reputation in the hope that richelle would

to the 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. sonnier's office. >> go to an adu bookstore and buy the mostt obscene, nastiest, man-boy love association book he could and buy him a subscription 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 his reputation, his 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 girlfriend so that ririchel wl think he's two-timing her. as the months go by and richelle is still dating sonnier,ixon becomes desperate. >> he said we have 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

between amarillo and lubbock. >> and next thing i know he tells me that richelle and dr. sonnier take these dance classes. and he showed me where the dance class was, where to go. >> reporter: shepard spends months in lubbock, watching the lovers. turnss out it was shepard who scares richelle in the early morning hours whenn he's staking out her gym.m. and it's shepard who i in a brazen move breaks into sonnier's back yard and takes thihis accental selfie. the flash alerting richelle and sonnier inside. >> it looked like a camera flash. and weind of shrugged our shoulders and said that was weird. >> reporter: shepard fails to dig up dirt on sonnier. so dixon grows impatient. >> was there a specific act that he was wanting done that -- was that what y'all were discussing? >> yes. >> and what was that? >> he -- he wanted him hurt. and then it gradually developed into having him killed.

interrogation an exhausted shepard gives police a blow by blow of what happened that night. a full confession. july 10th, 2012 is the last night shepard will stalk his prey. he breaks into sonnnnier's back yard armed with a gun and a knife and lies in wait. sonnier comes home makes himself a drink after a long day at work. suddenly, shepard is at the back window. >> i pull the gun out of the bag with the gatorade on it. i point the weapon with the bottle at him. >> rorter: shepard pushes through the window and fires, emptying his gun into sonnier. the doctor somehow finds enough strength to stumble out of the room toet away. but shepard is in pursuit and finds him in the garage, where he stabs him 11 times. >> he's laying on the floor, not

i check his pulse in his neck. he's dead. >>eporter: 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 embezzler. he's lots of things. as far as his role inthis, i think he was a pawn for mike dixon. >> reporter: so district attorn mt powell offers shepard a deal. rat out his good fririend d mike dixon in exchange for a life sentence instead of a death sentence. but who will the jury believe, a respected plastic surgeon or a convicted con man? and would one of them not live to tell? big news! the new sprint lte plus network is faster than verizon and at&t... based on data from the world's foremost authority on independent measurement. to celebrate, we're nna cut some prices in half. switch to sprint and save 50% onerizon, at&t or mobile rates. no gimmicks. no tricks. it's the biggest offer in u.s. wireless history! what abo verizon? 50% off. at&t too? 50% off.

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>> announcer: now more of "20/20" and "a last dance in xas." despite the fall chill rolling across the outer western plains, in downtown lubbock things were heating up as the biggest murder trial this town has ever witnessed kicked off. >> this prominent plastic surgeo >> dr. michael dixon -- >> accused of hiring a hit man. >> friend and businessartner david shepard. >> i cannot believe that they did this. it makes me so angry. lowlife scum and a piece of [ bleep ] doctor. >> reporter: when dr. mike dixon was s arrest k and brought to trial for his role in joseph sonnier's death, dallas sonnier was hellbent on bringing his father's suspected killers to justice. >>hat was your mindset going into that first trial? >> let's go [ bleep ] get these guys. >> reporter: but ass always, there's another side to this story, and there was another son in that courtroom.

he still is good dad. >> repeporter: arew dixon convinced his father is innocent. >> they're trying to proveim guilty, and he's fighting for his life. i mean,t's just terrifying and just so sickening. >> reporter: the man tasked with puttg andrew didixon's faer away, a hard-charging texas district attorney named matt powell. >> mike dixon's running the show and he orchestrate this whole thing. >> many people make the argument that mike dixon never laid a hand on dr. sonnier. >> he's just controlling the -- dave shepd's jusust another instrument for mike dixon. >> reporter: and that instrument dave shepard has agreed to testify. pitted against his friend mike penalty. >> this is the oldest story in the book. this is vengeance. this is revenge. this is pride. >> reporter: the motive? in courtroom 72 of the lubbock county courthouse the prosecution paints a picture for the jury of dixon as an obsessedcalculatating puppetmaster. >> he wanted her to suffer or he wanted her back.

that question is. but dr. sonnier was in th way. >> reporter: the plars of powell's case -- police find the gun shepard usedt the bottom of a lake, conveniently located behind dixon's office. and discover it's registered to dixon's brother. and they also find surveillance videos from the day after the murder that's s shepard ithe plaid shirt, dixon in blue. the two hangingng out. thick as thieves. >> 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. instead shepard attempts suicide. he slits his wrists. when he fails, who ds he call for help? his buddy mike. here they are. that's shepard towering over dixon as they head into the doctor's office to stitch shepard up. >> so he sews your hand up. does he discuss anything with you in reference to sonnier? >> he told me i need to keep my cool. >> reporter: prosecutors also

text messages between shepard and dixon. as shepard stalks sonnier for months. messages from dixon ordering shepard, you have to stay close, watch him in the a.m., go get 'em. and put it on him. finally, what's the price for murder between friends? police say dixon paid shepard for the hit in the form of a box of cuban cigars and three silver bars. bars that turned up at this pawnn shop in amarillo. one before the murder, two the day after the murder. sold by none other than dave shepard. >> in terms of demeanor he didn't strike you one way or the other, it sounds like? >> not at all. >> cououple day later he's on the front page of the paper. >> was blown away. >> reporter: but dixon's lawyers have an explanation for all of this. first the gun used they say shepard stole it from dixon's home. defense a attorney frank sellers shows me where. >> they came in here. they're picking out a cigar to smoke. and shepard opens this drawer here, and it's a gun. >> so that's how shepard knew a

>> exexactly. >> reporter: and the silr bars? the defense says they were for a business investment,, not a murderor hire. they say dixon only wanted shepard to try to take photographs of sonnier out with other women to show richelle sonnier wasn't all he was cracked upo be. >> in the days before they leave for paris he says, "it's got to happen tomorrow because the t is imminent." it almost sounds like somebody's trying to say attack or hurt somebody imminently. >> we believe it was an attempt to make the trip uncomfortable. get the photographs. >> reporter: and theyy say this was all because dixon was upset. he believed richelle was throwing her new relationship in his face. >> richelle was posting on facebook all the time how dr. sonnier was ten times the man that michael dixon would ever be. and he wanted to show richelle that she was wrong. >> reporter: zbl so from your perspective it wasn't about richelle shetina. it was about mike dixon and his ego. >> right.

he'd have been following her. >> were you in any way trying to flaunt your relationship? >> he was blocked 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 planted the seed by even discussi this relationship? >> plant the seed for a murder? no. absolutely not. >> mike is morally responsible for david shepard being down here. but not for the purpose of killing dr. sonnier. mike dixon never wanted that to happen. >> i asked him, you sure you want to do this, mike? i said, when you kill somebody, that will affect you for the rest of your life. you'll have nightmares. it willl bother you. and he goes, "doesn't bother me." >> reporter: and when it was time foror the trigger man to testify against his best buddy in open court, the sonnier family was sitting front and

>> he had a chance to get up there, confirm his story, point to that guy as the person who id him to kill my dad, and end it all. >> reporter: hee does end it. but not in the way dallas wants. shepard is about to drop a bombshell. >> but daddy, why dididn't you tell that? >> reporter: and make his own flesh and blood despise him. >> you've e made youelf a monster, dad. >> reporter: when we come back. i'm jey 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. he's always hanging 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." denitely not good for my back. this is the part i really don't like right here. (doorbell) a package! it's a swiffer wetjet. it almost feels like it's moving itself. this is kind of fun. that comes from my floor? eww! this is ep couch sitting. [jerry bell iii] deep couch sitting! performance...

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>> announcer: "20/20" continues with ryan smith. when the convicted murderer

his best friend mike dixon's trial, he was facing the victim's family,he jury, but perhaps most poignantly his three daughters, rachel, abigail, and haley. and they are not here to defend their father. >> you were in that courtroom to get closure. >> we were there more in support of the sonnier family. >> right. >> ye >> our h heart was broken for them. >> reporr: shepard's daughters saying their father is a murderer. >> and do you think that mike dixon paid your father to kill dr. sonnier? >> yes. yes. >> reporter: but on the stand a shocking twist nobody 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. >> i said well, just go behind him when he' not paying attention, hit him with a board. i said, you could probably kill him. and doc went -- like that. we'll talk about that later. >> reporter: but in the courtroom he suddenly changes

ner asked him to kil sonnier, letting his friend completely off the hook. >> you begin to question him. what happens? >> well, he completely digressed from what his statement was to law enforcement in the fact that mike dixon didn't have any involvement in this deal. >> reporter: theeteran prosecutor blindsided. >> what's going through your mind? >> okay, gamame on. >> in that ment i've never hated anyone more than i've hated him in my entire life. >> reporter: the shepard daughters also watching are embarrassed and hamed. >> it was cowardly. >> i mean, he has a chance to make it right and he completely ruined it. >> why do youhink he did that? >> he w trying to help out his buddy. >> reporr: the girlsompelled do something extraordinary. they apologized to thee sonnier family for what their father has done. >> what did you say to them? >> we are so sorry for what he has done to you and what he's continuing to do to you. >> reporter: and after shepard changes his story, back in jail,

it's a rare and raw look at a fractured family. >> but daddy, you didn't tell the truth. >> i did. >> you didn't s say anything. you just kept saying that you wouldn't tell them. >> but i did. >> why didn't you tell -- no, you didn't, daddy. you said i plead the fifth. i don't -- i'm not going to answer that. >> none of this is rit. none of it will ever be right. >> there's nothing i could do. >> no matter what i do -- they think i'm some kind of a monster. >> you've made yourself a monster, dad. >> reporter: you were 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. if shepard hoped to free h his friend, it works. the case ends in a mistrial. >> the only reason for the hung jury was david shepard's testimony. >> reporter: regardle, d.a. ma powell is undeterred. >> matt powell comes into the room where we're stanng, and

are going to get this guy. we are going to do this again. don't you worry. i've got you." and that's all i needed to hear. >> reporter: a 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 back yard. >> you look so happy. >> he was a good dad. he did dad things. you know, american dream kind of stuff. >> reporter: but that dream was over. the nightmare truth is andrew's father is facing capital murder charges and the second trial begins. >> amarillo doctor michael dixon is back on trial. >> reporter: and this time around prosecutor mike powell has a new witness. >> the number one most important thing from this second trial was the unbelievably courageous testimony of haley shepard. >> reporter: next, dave shepard's own daughter haley takes the stand.

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onward. toy's the day. carpe diem. tylenol 8hr arthritis pain has two layers of pain relief. the first is fast. the second lasts all day. we give you your day back. what you do with it is upup to you. tylenol . >> announcer: "20/20" continues with "a last dance in texas." lubbock, texas. haley shepard, the hit man's daughter, is on the stand. she takes the jury back three years. and you'll see why. it's hot summer night in amarillo, texas. her father, dave shepard, treats hihis daughrs to a fancy steak dinner, served with a side of suspicion. >> he had some money. i got a nice steak.

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 blue. he just randomly had money. and he didn'tt er have money. >> reporter: for his older daughter haley there was also a brand new celll phone. >> we all asked him, how do you have money? and his words were "i did some work for mike and he paid me early." >> reporter: this time the prosecutor calls her, not her father, to testify in mike dixon's retrial. and you think that was a prepayment for killing dr. sonnier. >> in retrosospect, absolutely. >> reporter: for victim joseph nnier's family haley's testimony is a game changer. >> she got up there and said, at dinner i asked my dad, i said where did you get this money? and david shepard says to her, i did some work for mike, he paid me early, don't ask what i did

>> reporter: it takes a new jury only three hours to deberate. >> and my handd was shaking like this because i kw we got a guilty verdict. i knew it. i knew it. i knew it. >> rorter: and he's right. >> the verdict is in. >> unanimous verdict. >> guilty on two charges. >> reporter: mike dixon is convicted on two counts of cacapital murder. >> whatt was you first reaction? >> i had to turn to my wife, and i had to say, he said guilty, right? he said guilty? we'd been waiting for that moment for over three years. >> reporter: for the sonnier brothers it's finally closure. >> whe you look at the photos of him, smug smil when you look at his mug shot from his arrest, smug smile. and he has had that smileor both trials, and it was so great to be able to know that we'd

>> he's lost everything. time with his family. >> reporter: another son, andrew dixon, remains convinced his father is innocent. >> when you think about the fact that he has to spend the rest of his life in prison without parole, how does that make you feel? >> it's unreal. it's like a nightmare. you lay your head down at night and it's just always there. always in the back of your nd. everything. >> reporter: remarkably, dave shepard's daughters have accepted both men's fate as justice servrved. >> 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 d doing very good. we are all okay. >> we're okay without him. >> i think he's wre he needs to be. >> reporter: as for the woman at the centeter of it all, richehelle shetina has a warning. >> there are real sociopaths and psychopaths that walk amongst us. they're charming. they sitit at the dinner table with you and your children.

bed with you. they're not capable of feeling love for you or empathy for anyone. when you see that, don't ignore it. get out. run. as fast as you can. >> reporter: ght, richelle shetina has put mike dixon out of her mind b says joseph sonnier will always have a place in her heart. >> i would tell him i loved him. and that i'll always -- i'll always love him. and i would just telll him how sorry i am. >> both dave shepard and his one-time best friend dr. mike dixon are now serving life in prison without the possibility of parole. dixon's lawyers are appealing that verdict. >> and that is our program for tonight. but be sure to join us tomrow night for a special "20/20" saturday.

major new turn in the 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 you tomorrow night. >> that's right. >> good night.pastor is practicing what preaches. the message he has to the man who hit him local five news at 10 is next.