don't think about her, that's for sure. i know i'll see her again someday. it's what keeps me going. th i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline". ♪ one woman, two men. her husband, the air force captain, and the staff sergeant, her rendesvous man. >> he was a playboy himself. >> announcer: one man too many. then suddenly there was one man less. >> it wasn't like bang, bang, bang. it was bang, pause, bang, pause. >> which sounds like what, excuse? >> you could take it that way, yes. >> announcer: a cold-blooded killing but who pulled the trigger? did jealousy drive someone to murder or did she?

>> michelle theer was a brilliant, coming, ruthless woman. ♪ >> announcer: hello. welcome to "dateline". the story you're about to see centers on a death of a military man thousands of miles from a battlefield. a dedicated officer who survived war zones only to be caught in the cross fire of a lover's triangle. here is keith morrison. ♪ >> reporter: what was she thinking when she went to the computer, when she typed in those five little words? did she not understand where those little words might lead? >> i need an ambulance. >> where are you at? >> i don't know. >> okay. what's your name? >> michelle.

>> reporter: michelle theer was, no doubt about it, dissatisfied. here she was young, successful, attractive, and yet wasn't exactly boredom that was eating at michelle. after all, she was just starting a new career as a psychologist, often counseling troubled couples. >> she was relatively new with her license. i think that was her first real job. >> reporter: of course, michelle would have laughed at the idea that pretty soon now event would propel her to such notoriety that newspaper reporters like melissa stoddard diaz would be poking around in her past. >> michelle, from everyone i have spoken to, wanted to be somebody and really worked hard to get to where she ultimately got her degree and became a professional. >> reporter: but then michelle, even at an early age, always seemed confident about getting what she wanted. she was just 16 when she started dating marty.

marty theer was a couple of years older, worldly, bright, friendly, had big plans. he wanted to be an astronaut. he went to the air force academy. ♪ >> reporter: she was 20 when she married him at the academy's famous chapel outside colorado springs. >> marty, you may kiss your bride. >> reporter: this was back in 1991 when marty was all she ever wanted. long before she talked to that psychologist, agreed to record for the record her thoughts about the weird events yet to come and those happy days with marty, too, of course. >> we did everything together. he treated me really well. i thought we had the perfect relationship. we were best friends. >> reporter: he was the dashing young officer back then. she, his lovely bride. the future, she imagined, an endless honeymoon in which

marty's air force career would take them to exotic destinations all around the world. she just didn't imagine that world would be unromantic air force outposts in oklahoma, alabama and florida and finally fayetteville, north carolina. they came here in 1999. marty was captain theer by then, flew one of those huge c-130 cargo planes. all of that time alone, not so easy on a marriage as she revealed during the tape-recorded interviews with psychologist dr. debbie layton thole. >> michelle talked about a few problems in the marriage, primarily growing apart over the years. marty was away for extended periods of time. she had a hard time with that. it was getting more difficult for her. it was lonely. >> reporter: sometimes he was gone for mont, and when he did finally come home military families have come to know that adjustment period all too well. they bickered, they argued about

her housekeeping, his job, about having children -- he wanted them, she didn't. she was worried she would be stuck raising them by herself in a town where she was lonely. >> here i was in fayetteville with no one to pick up the phone and call. >> reporter: that actually is about the time it started. harmless really, just a few key strokes, see what might happen. goes on all the time these days on the internet. sexy brew net seeks man. before long her internet inquiry got a response, from him. his name was john, john diamond. >> john loved women. john was a lady's man. john always had girlfriends. >> reporter: so debbie devorak, could see him responding to

michelle. >> my brother has a great personality. he is an attractive guy and his personality makes him that much more attractive. >> reporter: then a few days after meeting online they met in person at a local restaurant. >> he was charming. he was funny. talked about movies and music and things that me and marty didn't talk about. >> reporter: john diamond was an army staff sergeant based at ft. bragg and trained as a sniper, highly regarded, decorated. had been in the service since he was 18. >> by all accounts he was a good soldier but he was a playboy himself. he had been married once before and had a child from his first marriage, and he left the first wife and married and they had a son together. >> reporter: michelle didn't know that john was still married, but maybe it didn't matter. at least not then. she loved the sex, the attention, the excitement. >> i mean he was very attentive, he was very affectionate, he was very adoring. >> yeah, it sound great.

>> reporter: what made her so desirable to him? >> i think it was just the sex. that's what he was obsessed with. he was smitten with having sex with her. >> reporter: for michelle? well, it was more lust than love. >> she felt that the affair did not take away from the fact that she loved marty. she said he was the love of her life and that she never loved john diamond. >> reporter: and marty? he was in the dark, of course. when michelle told him their marriage was in crisis and they needed to see a counsellor -- >> he wouldn't agree with counseling and i moved out. he was shocked. >> reporter: michelle got her own place and spent much of that steamy fayetteville summer with john diamond. >> he was so attentive. he would rub my feet for five hours if i wanted him to. >> reporter: diamond was apparently nuts about michelle, never met anyone like her before. >> she challenged him in ways that he had never been challenged before. >> reporter: paul woolverton is a reporter with "the

fayetteville observer." >> he wshe was strong and excit for him. >> reporter: but was he enough for her? apparently not, because after three months on her own michelle went back to marty. >> she felt that the marriage could survive despite everything that had happened, that they could make it. >> reporter: so john and michelle's six-month affair seemed to be off. but then a few weeks later it was apparently back on. the two traveled to the tropical island of saba where michelle interviewed for a job at a local university, and later that fall a romantic meeting at a raleigh motel where she celebrated her birthday. she would insist it was a relapse. >> i knew that i loved marty and i knew that i wanted to make it work in my heart. >> reporter: but john diamond was devastated, or so said michelle. >> he said specifically, i'm

going to kill myself, i can't live without you, you can't do this to me, i'm going to go drive my car off a bridge. >> reporter: it was awful, said michelle. diamond kept calling. made a scene at her office in front of some student she taught, even threatened to call marty and tell him everything. so nearly a week after that romantic night in raleigh, michelle says she met john at a local restaurant to end the affair, gently but for good. >> we had the whole talk, you know, we can be friends, and this can never happen again, never, never, never. he seemed very calm, very rational. >> reporter: so now it was december. time for peace and joy, christmas parties. one in particular at which the spirits flowed and the fuse burned down to its explosive end. somebody was about to die.

and somebody else wasn't taking any chances on missing. >> announcer: coming up -- >> it wasn't like bang, bang, bang. it was bang, pause, bang, pause. >> which sound more like what, execution? >> you could take it that way, yes. >> announcer: when "dateline" continues. ouncer: when "datelin continues. to treat her frequent heartburn, marie could only imagine enjoying freshly squeezed orange juice. now no fruit is forbidden. nexium 24hr stops acid before it starts for all-day, all-night protection. can you imagine 24 hours without heartburn? for all-day, all-night protection. this, is why we no longer have to worry flushing too much toilet paper, will back up our system. but dad, rid-x contains billions of enzymes proven to break down even paper to keep your whole septic system healthy. for paper, grease or waste breakdown. use rid-x. of a lifetime. it's "progressive on ice." everything you love

about car insurance -- the discounts... the rate comparisons... and flo in a boat. ♪ insurance adventure awaits at "progressive on ice." tickets not available now or ever. ro ro ro ro

♪

hear in here in the heart of the american bible belt, on the fringe of bases, is fayetteville, north carolina. imagine, most of the suburban strip mall devoted to strip clubs and a downtown which is charming, elegant even, and has seen about everything. it is an old town, fayetteville. that tower marks the spot where north carolina ratified the federal constitution in 1789. i'm standing on what was a slave market. sherman fought battles here in the civil war. now it is a military town and 160,000 acres back there is the army's ft. bragg where soldiers prepare to go to war. nestled up beside that is pope air force base. two institutions, two professional military men, one

woman. that woman, michelle theer, now found herself caught between her husband marty, the air force captain, and her former lover, army staff sergeant john diamond who just wouldn't go away. >> i told him, i don't want to leave my husband. i never told him, i love you. i never said, i want to be with you. i mean i think i was pretty straight up. >> so now with the holiday season in full swing and a new commitment to her marriage, michelle and marty were on the road to raleigh for a night out. traveling with them was another couple from her office. >> they had gone to this christmas party that she specifically asked per boss her marty could go. >> it was sedate by office standards and over early since marty had to fly first thing in the morning. now it was 9:30 p.m. marty, michelle and the co-workers prepared to leave the restaurant. then an interruption. michelle excused herself, made a

brief phone call out of earshot of the others. then the drive to fayetteville, one hour. they dropped the other couple at michelle's office, then left for home. stopped on the way for gas. and then sitting at the gas pump michelle told marty she had forgotten something at the office. >> we ended up turning around and going back to the office to get some stuff that i needed so that i could stay home and work that night. >> marty parked behind the office building. michelle walked up an outside staircase, disappeared inside. marty, waiting in the car. apparently he got impatient, headed up the stairs to check out michelle. that's when it happened. she found him, she said, at the bottom of that outside stairway. she could see the blood. she ran to the nearest store, called 911. >> i need an ambulance, please. my husband -- >> somebody shot your husband?

>> i think so. >> where are you at? okay. what is your name? >> michelle. >> within minutes fayetteville police and paramedics arrived and they found michelle cradling her husband in a pool of blood but it was too late. marty theer was dead. he was just 31. because marty was an air force captain military investigators were soon on the scene as well as police, making this a joint investigation with the fayetteville pd. both teams were eager to speak to the only known witness, michelle theer. office of special investigations agent vince castille. >> she said she heard what sounded to her like three bangs of a car backfiring. >> did she tell you what she did at that point? >> she opened the door and notice it her husband was laying at the bottom of the stairs. >> she told them she thought she saw somebody moving in the

bushes near the stairway but she wasn't sure. >> i think initially police were looking at perhaps a robbery of some type. >> detectives combed the parking lot, surrounding area, but found no one on this cold, dark december night. >> there was a man who lived behind the office building who heard the shots fired, who later said that -- he said, somebody's getting murdered out there because of the order in which the shots were fired. they were very calculated. >> it wasn't like, bang, bang, bang. it was bang, pause, bang, pause, bang, pause, a space between each of the five shots. >> which sound more like, what, an execution? >> you could take it that way, yes. >> at the top of the stairway were a few clues, bullet holed sprayed in the wall, sequins from marty's holiday suspenders littered the landing. looked like he was at the top of the stairs, shot from down below. >> i think that's what made him roll down the stairs, and the final shot was to the back of

his left ear. >> the kill shot? >> the kill shot, close range. >> they found shell casings in the parking lot. appeared to be from a .9 millimeter handgun. but there were no fingerprints, no footprints, no useful dna. but investigators did find marty's wallet, still on him, complete with cash and credit cards. >> marty theer was not robbed. the other thing was that it was a very, very cold night. not a night where a prowler would be out on a street just looking to find someone. it made it very suspicious. >> investigators couldn't imagine who would want to kill such a wonderful man like captain marty theer. but, of course, out in this dark parking lot they didn't know any of what you know. not yet anyway. assuming what you have heard so far is the real story. and as you will see, the question of what was true and what wasn't could be very tricky indeed.

>> announcer: michelle said she had gone back to her office because she had forgotten something. so what took so long? coming up -- >> they found a candy wrapper that had been opened and in the trash can. it was almost like a scene where she had just gone upstairs and sat and waited for a few minutes. >> announcer: for what? when "dateline" continues. conti, and my lack of impulse control, is about to become your problem. ahh no, come on. i saw you eating poop earlier. hey! my focus is on the road, and that's saving me cash with drivewise. who's the dummy now? whoof! whoof! so get allstate where good drivers save 40% for avoiding mayhem, like me. sorry! he's a baby!

pronamel repair can actively help repair weakened enamel. it takes minerals and it drives it deep into the tooth's surface. pronamel repair takes it to the next level.

♪

it was a week before christmas 2000 and fayetteville was aglow, but not everywhere with the lights of christmas. and a few hours after air force captain marty theer turned up dead in the parking lot of his wife's office building, the news was out and it was big. michelle theer, now marty's grieving widow, told the police she was inside her office looking for a book when she heard someone firing outside. >> by all accounts it was an assassination. >> greg butler was a deputy assistant attorney in fayetteville at the time. >> someone would kill marty theer that night, there was no evidence of any robbery. there was no evidence any other thing going on here. >> though inside michelle's office what they found seemed, well, a little odd maybe. >> she had gone to the bathroom. the toilet had not been flushed. they found a candy wrapper open and in the trash can. it was almost like a scene where

she had just gone upstairs and sat and waited for a few minutes because obviously to find a book wouldn't take very long. >> strange. hard to know what it meant, if anything. as dawn approached michelle was allowed to go home, and later that morning her boss arrived. so the cops talked to him, too. >> during that interview it came out that she was having marital problems and having some extramarital affairs. >> funny, michelle hadn't mentioned anything about that. so detectives went to her house to follow up and, sure enough, michelle did admit having an affair with staff sergeant john diamond. michelle also said she hadn't spoken to diamond in two days, but when pressed she remembered trying to call him unsuccessfully just before leaving that christmas party, about 90 minutes before marty was murdered. so detectives decided to check their cellphone records and discovered -- >> they had been calling each other regularly, a minimum of 20

times a day. >> now detectives paid a visit to john diamond, who freely admitted having a sexual relationship with michelle, but claimed she was just one of many ladies in his life. and as for the night of the murder? he had an alibi. he was home with his family watching a movie. still, michelle must have harbored some sort of suspicion about john diamond, who is now a person of interest. not long after the murder she told detectives and that psychologist she went to see diamond, conduct her own investigation, find out what he knew about marty's death. >> i said, do you know anything about this. you know anybody that had anything to do with this. he said no, i would never do anything to hurt you. i know how much you love him. he looked so trustful. >> mind you, as police were soon aware, michelle had many opportunities to question her friend john after her husband

died. >> there were witnesses saying that he parked down a little side street and then walked through their yards, going in the back door of her house. >> he couldn't stay away from him. >> yeah, he was going there and staying all night. >> not commonly the way widows grieve, spending the night with the person of interest in her husband's murder. but michelle told psychologist dr. debbie layton thole she needed support from someone, anyone. >> she felt more alienated from family and friends and more threatened by the police. the only person in her life that was willing to be there for her was john diamond. >> i knew that i was depressed and i was getting more and more depressed, and i think i went to john for comfort. >> in fact, just a few weeks after marty's murder michelle and john drove to florida for a weekend. she wanted to see a former professor for grief counseling

while he stayed with his sister debbie. >> he acted as if nothing was wrong because he knows he didn't have anything to do with it, he didn't shoot him. >> so who did kyle captain martin theer? was it possible john diamond executed his romantic rival? he may have had a motive, the police were suspicion, but the physical evidence was rather weak. so they kept digging in the arcane world of phone records. boring but sometimes revealing. one telephone number in particular caught their attention, a call from diamond to one of his army buddies at ft. bragg. >> so we asked him if diamond had any access to any weapons. he said that he loaned diamond his personal pistol. >> which just happened to be a .9 millimeter beretta pistol, the same kind of gun that killed marty theer. >> joon diamond actually

borrowed the gun from him during the time frame the murder occurred. he had possession of it. >> detectives were not only convinced he had access to a gun but maybe even the actual murder weapon. did he still have it? well, apparently not because just a short time after cops went to the home of diamond's army buddy asking about that gun, diamond made a phone call to ft. bragg and reported that his car which he claim to have left in the base parking lot had been broken into and one of the things stolen from it was a .9 millimeter handgun. >> when we got there the passenger door had already been opened and there was a pile of glass sitting next to the rocker panel on the passenger's side. but if you'll look on the inside, there was very little glass. >> what did that tell you? >> he had the door open when he broke the window and then tried to make it look like it was broken in. >> a bogus break-in?

military police sure thought so. john diamond was arrested for admitting that he brought an unregistered gun on base. clearly diamond was now the prime suspect in the murder of captain marty theer. but was he really the killer? >> announcer: coming up, a secret about john and michelle's steamy affair becomes very public. >> she was taking him to these sex clubs and saying, it's okay, go -- you know, if you want to have sex with her, that's fine. and he just, wow, okay. >> announcer: when "dateline" continues. " continues. see you at 5! seriously? protection. lysol kills over 100 illness causing germs and viruses. even those that may cause cough. lysol, what it takes to protect. whoh no, that looks grossit. what is that? you gotta try it, it's terrible.

i don't wanna tray it if it's terrible. it's like mango chutney and burnt hair. no thank you, i have a very sensitive palate. just try it! hey guys, i think we should hurry up. if you taste something bad, you want someone else to try it. it's what you do. i can't get it out of my mouth! if you want to save fifteen percent or more on car insurance, you switch to geico. it's what you do. dog, dog, dog. i've always loved and i'm still going for my best, even though i live with a higher risk of stroke due to afib not caused by a heart valve problem. so if there's a better treatment than warfarin, i'll go for that. eliquis. eliquis is proven to reduce stroke risk better than warfarin. plus has significantly less major bleeding than warfarin. eliquis is fda-approved and has both. what's next? sharing my roots. don't stop taking eliquis unless your doctor tells you to, as stopping increases your risk of having a stroke. eliquis can cause serious and in rare cases fatal bleeding. don't take eliquis if you have an artificial heart valve or abnormal bleeding. while taking eliquis, you may bruise more easily

and it may take longer than usual for any bleeding to stop. seek immediate medical care for sudden signs of bleeding, like unusual bruising. eliquis may increase your bleeding risk if you take certain medicines. tell your doctor about all planned medical or dental procedures. eliquis, the number one cardiologist-prescribed blood thinner. ask your doctor if eliquis is what's next for you.

♪ hello. i'm dara brown. here is what is happening. the death of top iranian official case case near baghdad's airport is prompting threats from tehran of forceful revenge against the united states. president trump defends the decision, saying the action taken was not to start a war but

to stop one. today six more were killed in another u.s. air strike north of baghdad. the u.s. is now deploying approximately 3,000 troops to the middle east as american civilians are being told to evacuate from iraq. now back to "dateline". ♪ >> announcer: welcome back to "dateline". i'm craig melvin. army staff sergeant john diamond was arrested for admitting that he had brought an unregistered gun on to a military base, the same type of weapon used in the fatal shooting of his lover's husband. he was now the investigator's prime suspect but they needed more evidence. continuing with our story, here is keith morris. >> a few weeks after the murder of captain marty theer, a fayetteville police detective named c.t. williams was asked to have a look at a couple of computers seized from michelle theer's home, see if they might contain any clues. >> i just was looking for

documents or text messages or e-mails. >> like an onion he peeled back the layers of text, which though they had been deleted reappeared under his expert touch. boxes of deleted documents, 88,000 of them, buried deep inside michelle's hard drive, and out spilled some of michelle's most intimate sexual secrets. >> she seemed to be seeking affairs with a number of people over time. she was looking for an alternative lifestyle. she was seeking a partner and escort for sexual spinner type clubs. >> that would be carolina friends, a swinger's club. it boasted more than 10,000 members. within michelle's lengthy list of e-mails detectives discovered that not-so-innocent inquiry she typed seeking a rendezvous man. that was john diamond who quickly replied and who quickly joined michelle in the

lifestyle. >> she was taking him to these sex clubs and saying, it's okay, go. if you want to have sex with her, that's fine. go, i'm fine with it. he just, wow, okay. >> as investigators sorted through the sexually-charged e-mail they could plainly see a story as old as time. john diamond fell head over heels in lover with michelle. >> here was her little puppy she could control like a child. >> john diamond appeared to be a man obsessed. i can't wait until you come back so we can take care of each other. you know sex, sex, sex, and, of course, more sex. i know that we're meant to be together and are kindred soulmates. i will always love you know matter how you've hurt me. >> you could tell it was changed from a sexual relationship to completely, totally enamored with her anyway you could

imagine. >> and he was getting desperate. >> he wants to be with her. his plans were to be with her, do anything, keep the woman he was totally in love with. >> anything? perhaps even kill the man that stood between him and michelle? >> she was beginning to set him up. she was playing his emotions. >> she was pushing him away kind of? >> push him away in some ways without really completely pushing him away. >> push/pull. >> i think she was manipulating him at that point. >> manipulating him into murdering her husband? why would she want to do that. >> there was a $500,000 insurance policy taken out on marty theer in 1999. >> and the sole beneficiary, michelle theer. they were convinced she typed the e-mails and sent them to herself to steer them away from herself and to diamond so he would take the rap. >> he never expressed a love

feeling to me. unless you come to me with a handwritten letter that he was obsessed with her i will never believe that. >> how do you know that? >> he told me he did not want to marry her, to spend the rest of his life with her. >> according to debbie it was michelle who was obsessed with john. never more so than when she gave debbie two wedding rings to take to her brother who at this point was locked in the bringing. >> i think she was obsessed with him to the point that she couldn't control him. she couldn't control the situation. >> she wanted to control it and if she gave him a wedding ring and he wore it, wouldn't that give her all kind of reason to claim that he would do anything for her, including kill her husband? >> that could be. i don't -- i don't know. what i got from him after he was arrested was he didn't want anything to do with her. nothing. >> with or without michelle, john was in big trouble so he lawyered up with prominent fayetteville attorney corey

brewer. >> i believe that he was an innocent man wrongly accused, that any rational interpretation of the circumstantial evidence is consistent with sergeant diamond not being the shooter. >> but military investigators were convinced diamond was the trigger man and decided to quickly proceed with their case against him. and michelle? remained free, and what did she do? well, she left town. >> i think she planned to kill her husband a long time ago. i think she waited and researched and waited for that right person that would look and fit the part to pin it on. >> if that was true, michelle's plan was working perfectly, because in a few short weeks john diamond would be on trial for murdering her husband. >> announcer: coming up -- the prosecution's case against john and the defense's case against michelle. >> michelle theer was a brilliant, cunning, ruthless

woman who wanted her husband done. >> announcer: when "dateline" continues. ne. >> announcer: when "dateline" continues.

♪ in the dead center of ft. bragg, north carolina, is a nondescript red brick building. this is where army staff sergeant john diamond found himself, a prime suspect in the murder of air force captain marty theer. >> military justice is much swifter than civilian justice. so he goes to the article 32

hearing, which is like the grand jury. they immediately find cause and they charge him. >> and nine months after the murder in a small ft. bragg courtroom, diamond went on trial before a military jury. >> diamond was very, very cocky at the beginning. he would laugh and joke with reporters in there. he was just so sure that he was going to be acquitted. >> but john diamond wasn't the star of his own trial, michelle was. she was free as a bird then, though still under investigation by fayetteville civilian homicide cops, and here she was called to testify at her former lover's military trial. >> she shows up. her hair is now like a red color that she's colored it. she's lost a bunch of weight and she's got a gaggle of media following her into the building. >> it was all image, no substance. michelle took the stand, but took the fifth. the prosecution's case against

diamond, it's accusation was simple. driven by his obsession for michelle, he conspired with her to kill her husband by borrowing the gun, arranging to be in a position in that dark parking lot, waiting until marty theer had placed himself in the kill zone at the top of the staircase outside michelle's office, and fired the five shots that killed him. as for diamond's alibi that he was home with his wife watching a movie? that now ex-wife came to court and told the jury that the evening wasn't quite like that. halfway through the movie his phone rang, she said, and suddenly he was gone. and what's more? >> her mother heard him come home, you know, in the wee hours and wash clothes. >> true? maybe not said defense attorney corey brewer. her story changed after she talked to police. >> she was afraid of the government. i don't think that she was telling the truth. >> had she been pressured?

besides, said the defense, there was no dna, no footprints, no fingerprints to prove diamond shot marty theer. anyway, diamond was a trained sharp shooter but the shots that felled marty were sloppy, most badly aimed. must have been the work of an amateur, said diamond's attorney, an amateur like michelle. >> michelle theer had asked for the gun several days before the murder. she had told him her husband had been abusive and that she was afraid of him. so he gets a gun and he gives her the gun. now, he didn't think she was going to kill him with the gun. >> did she just use him, know that he was somebody she could use to serve her purposes? >> she set this up to kill her husband because she wanted the insurance money and for sergeant diamond to take the fall. michelle theer was a brilliant, cunning, ruthless woman who

wanted her husband dead. >> the military jury, however, didn't see it quite that way. >> the verdict was swift. guilty as charged. and from that moment on his demeanor changed. i mean it was like somebody just sucked the air out of him. the john diamond full of bravado and ego just shh ririveled away >> diamond was sentenced to life in prison without parole. at the time his family was furious, convinced he was framed. >> you don't expect to be convicted on theory and myth and what-ifs. show me blood. show me a gun. show me a timeline that works. show me those facts. i'll believe until the day i die that she killed her husband, that she planned to have my brother go down for it so she could live this happy, wonderful life. >> curious thing that. as john diamond settled into a life in prison people around fayetteville could see to their

great disapproval that michelle went on with a life uninterrupted and then quite suddenly they didn't see her at all because michelle theer disappeared. >> announcer: coming up -- michelle wasn't just a missing woman, she was also now a wanted woman. >> there's some speculation that she was tipped off that she had been indicted because she seemed to really sort of fall off the face of the earth. >> announcer: when "dateline" continues. ouncer: when "datelin continues. hes you want to wear always seem to need an iron? next time try bounce wrinkle guard dryer sheets. just toss it in the dryer to bounce out wrinkles. we dried these shorts with bounce wrinkle guard, and a pair without. the bounce wrinkle guard shorts have fewer wrinkles and static, and more softness. it's the world's first mega sheet that does the job of three dryer sheets. it also comes in unscented. if you don't love bounce wrinkle guard, we'll give you your money back.

wheyou want relief... fast. only thermacare ultra pain relieving cream has 4 active ingredients to fight pain 4 different ways. get powerful relief today, with thermacare. skip to the good part with alka-seltzer plus. now with 25% more concentrated power. nothing works faster for powerful cold relief. oh, what a relief it is! so fast! oh, come on. flo: don't worry. you're covered. (dramatic music) and you're saving money, because you bundled home and auto. sarah, get in the house. we're all here for you. all: all day, all night.

(dramatic music) great job speaking calmly and clearly everyone. that's how you put a customer at ease. hey, did anyone else hear weird voices while they were in the corn? no. no. me either. whispering voice: jamie. what? liz, you nerd, cough if you're in here! shhhh. i took mucinex dm for my phlegmy cough. what about rob's dry cough? works on that too. and last 12 hours. 12 hours? who studies that long?! mucinex dm relieves wet and dry coughs for 12 hours with 2 medicines in 1 pill.

welcome back it "dateline." shortly after john diamond was convicted in the murder of her husband, michelle did something expected, she left fayetteville, north carolina without a trace. authorities weren't done with her yet, but were they be able to track her down? here with the conclusion of "deadly ambush" is keith moore. >> leavenworth federal prison. doing time doesn't come much harder than it does here. this is where john diamond was serving a life sentence for murdering air force captain marty, but his former lover michelle, seems to have dropped right out of sight. where was she? people weren't seeing her around fayetteville. the d.a. meanwhile was convinced she must have conspired with

john diamond to kill her husband. she was the brains, he was the brawn, or in this case, though it was all circumstantial, to greg butler, it was persuasive. >> there is evidence, i don't think there is any question as to who was involved, diamond and her together. >> the evidence? the life insurance. the affair. the access to a murder weapon. those emails. the coverup. taken together, it was enough to convince a grand jury. and finally, in may of 2002, nearly 18 months since her husband was killed, michelle theer was indicted for first-degree murder and conspiracy. but arrested? no. why? >> there's some speculation that she was tipped off, that she had been indicted, because she seemed to have really sort of fall off the face of the earth, right before that came down. >> michelle theer vanished. no one, not even her family knew

where she was. lauderdale by the sea is a charming little town, just north of miami. quaint and quiet. low profile. in the summer of 2001, cindy, a local landlord, met with a woman who wanted to rent a room at her cottage. >> she gave her name as liza pendereggen, well spoken, intelligent, she told me she was on the run from an abusive boyfriend from california. >> she made friends around the neighborhood, before long she had a new beau. she kept in touch with her family, secretly, only called on pay phones, for example and rarely. two months after michelle arrived in florida, she asked her boyfriend to call her parents, pass on a message, use a pay phone, she told him. and maybe she forgot or perhaps

he wasn't listening, but u.s. marshals were monitoring when you called from his parent's house phone and they looked up the number. >> they said he had a son in his late 20s who had a son in south florida. >> the cops found him. staked him out. and followed him to that little white beach cottage to where he and michelle were in for a big surprise. >> following a developing story, out of florida. a woman wanted for the murder of her husband, has been arrested in florida. >> at the time of her arrest inside the apartment, we found magazines describing ways to go under cover in the united states. obtain new identity. >> books, too. on learning spanish. travel guides for several latin countries. and an array of fake i.d.s. and then there was michelle's appearance. >> she had changed her

appearance. cut and dyed her hair. plastic surgery done. >> do you have anything at all to say? >> any comments? >> michelle, her face still red and swollen and smeared with ointment from cosmetic surgery was driven back to fayetteville, charged with first-degree murder and locked up without bail. and two years later, in september, 2004, after turning down a plea deal that would have imprisoned her for ten years, the prosecutor laid out his case against michelle theer. the proof? for one thing, all those intimate emails would show, said the prosecutor, how michelle manipulated diamond into a fatal frenzy and made him her fall guy. >> he was so upset, he couldn't have her, he would want to kill himself. if you're willing to kill yourself, it would not take much for that to happen to someone else and michelle herself, got

to the point arrived. >> the point arrived said the prosecutor after the office christmas party, when michelle called marty to say she was headed to the kill zone, the parking lot of the office building but needed him there alone. after they dropped two co-workers at the lofts, said the prosecutor, michelle made a crucial move that inextricably linked her to the murder, driving home, stopped for grass, michelle by her own admission, had marty return to the office, supposedly to pick up some work. marty became evasive, went up the stairs to check on her. and thus walked into an ambush. >> when they left, there was no way for that shooter to have any reason to believe that they were coming back unless he had known through a prior conversation, michelle feared, he was going to bring him back to that location, up into her business, leaving him outside the door, so that he could then murder her husband.

>> that was really your smoking gun? >> that was the smoking gun that tied her to it. >> michelle did not testify. nor did john diamond. her attorney belittled the state's evidence as circumstantial. among those speaking for michelle, they called in this doctor, debbie, and interviewed michelle about her relationship, to testify as an expert witness. those were the recorded conversations. excerpts which you heard earlier. the doctor told the jury, michelle wasn't manipulating diamond by starting and stopping their illicit romance. it was something else. >> when somebody is in a long term affair, there does tend to be a pattern of pulling away and then coming back together, an inability to be decisive. that's not unusual with affairs. >> besides, claimed the defense, being involved with another man didn't mean michelle was also involved in murder. the two sides battled through

three months of trial time. from labor day, past thanksgiving. 11-week trial. three hour deliberation. the verdict? guilty. >> she stood up, they put the handcuffs on her, and she walked out of the courtroom, and she never looked back into the courtroom area. not even toward her family. >> michelle theer now sits in a north carolina prison, halfway across the country from her co-conspirator john diamond. today these former lovers share only one thing. life without parole. >> he supported her. heart felt. and there's certainty that she was the bad one. she did it all. and he didn't do anything. >> and her supporters say they blame him, and she did it without knowledge. >> michelle theer rolled the dice and turned down a deal that would have released her before long. instead, the woman who followed hers did the satisfaction

through an internet romance went on trial. and as a result, would die in prison. >> that's all for this edition of "dateline." i'm craig melvin. thank you for watching. good morning, everyone. i'm ayman mohyeldin, alongside yasmin vossoughian here in new york at msnbc world headquarters. it is 6:00 in the east, 3:00 out west, you're watching special coverage of latest developments following the u.s. air strike that killed soleimani. there is a lot to cover today, from the middle east, to washington, here is the very latest. in baghdad this morning, thousands are on the streets for a funeral for the iraqi militia commander who was also killed in the u.s. air strike. u.s. marines are keeping up security at the embassy compound in baghdad which came under attack in the days before the air strike. and u.s. oil workers are leaving iraq, in keeping with e