her father, her mother, snatches of memory, ever farther away. >> that's all for this edition of "dateline extra." i'm craig melvin. thank you for watching. it's been 15 years of frustration, of tears, and fighting for what we wanted. how long can you keep reliving your sister's murder? >> reporter: it all began when this bestselling author married this elegant executive. >> they brought us together. they made us a family. >> but in the we hours of a winter night -- >> i found her at the base of the stairs. >> reporter: kathleen peterson,

dead. >> was this a fall, or was this murder? >> reporter: tonight a mystery we've covered for more than a decade comes to a shattering end. >> it did not look like a fall. >> reporter: michael peterson, under suspicion. then a bombshell revelation about another woman, from his past. >> liz was on the floor, and there was a puddle of blood under the staircase. >> two women that appeared to die the same way. two women associated with michael peterson. >> reporter: what are the odds? >> yeah, what are the odds? >> reporter: at trial, one expert -- >> this is the scene of a beating. >> reporter: -- would make a slam-dunk case for petersen's guilt. >> the jurors were captivated by his testimony. >> reporter: but were his dramatic experiments, legit? >> it's designed to get a result. it's not scientific at all. >> reporter: now, in his only network interview, michael peterson on the twist that might finally lead to the truth. >> the most difficult decision i ever made in my life. >> reporter: a writer at the center of a story even he couldn't make up. i'm lester holt and this is "dateline."

here's dennis murphy with "down the back staircase." >> reporter: you might take him for a retired english professor from one of the universities in the raleigh-durham area. preppy. witty. back when a sparkling storyteller welcome at so many of the best dinner tables. but nowadays in this part of north carolina, michael peterson is known not as the novelist he in fact is, but as that man, the notorious husband, the one with the wife dead at the bottom of the staircase. you were not only the prime suspect, you were the only suspect. >> the only one. >> there was massive amounts of blood. how do you explain it? was this a fall, or was this murder? >> reporter: exactly what did happen on that staircase? and what is the truth about michael peterson? a man once sentenced to die in prison for the commission of a

homicide he has always maintained was nothing but an accident. innocent, he asserts, but the novelist in him knows full well the irresistible appeal of the storyline he says he got swept up in. >> sex, money, murder, my god! what more could you have? >> reporter: tonight, one of the most compelling mysteries we've ever covered as you haven't heard it before. >> the people who believe in you will always believe in you. the people that don't never will. >> reporter: michael peterson in his own words. on the marriage, that fine old house. the blood spatter expert who wasn't. and the family friend found dead in another staircase far away in time and place. >> lightning don't strike in the same place twice. >> reporter: there's even a theory about an owl. >> whooo done it, huh? >> oh, it's just awful. >> reporter: we're going to need some time here. it's both complicated, and a simple question -- so if i were to ask you, as i do right now, did you bludgeon kathleen that night on the

stairway of the house and cause her death? >> no. no. no. ♪ >> reporter: let's go back to the night early december 2001, and stroll up the driveway of the gracious, rambling house in one of durham's better neighborhoods. michael and his wife kathleen are out back by the pool, as the story goes, finishing off a bottle of wine. in the living room, the christmas tree is already up, the grown peterson children expected home for the holiday. christmas was big for kathleen. >> oh, good lord. yes. and valentine's day and halloween -- she made a celebration out of everything, everything. >> reporter: kathleen's daughter caitlin, step-daughter to michael, says her mom was always happiest at the holidays. >> she loved christmas. she loved being in the mood, playing christmas music from the start of december all the way through new year's. >> reporter: it was the kids, actually, who brought kathleen and michael together. his first marriage had started to fall apart.

she was separated. michael was raising his two boys and two young girls, margaret and martha. the girls became neighborhood playmates with kathleen's daughter caitlin. >> they played -- oh my god, barbies and those little -- my little ponies and those damn little trolls. all the time, all the time. and then kathleen came over to borrow a book one night. and that's when it began. >> reporter: as the kids spent more and more time together, so did michael and kathleen. it wasn't long before they approached the kids about becoming a family together. >> they sat me down and said, "you know, caitlin, how would you like it if martha and margaret come to live with you?" and i just immediately thought, "a permanent sleepover!" >> reporter: and that's exactly how michael presented it to his two girls. margaret's the older. >> it's really funny. i think he put it, "we're gonna have a long sleepover," and we said, "yeah!" >> reporter: her younger sister, martha. >> of course we want to live with caitlin and kathleen, and play barbies, and, um, be a

family together. >> reporter: so michael and his four kids and kathleen and her daughter became a blended family. he was a former u.s. marine-turned-full- time writer who liked to draw on his wartime experiences in vietnam. one of his vietnam books got a big advance, money that went towards buying that fine house. >> they said, "we're thinking about moving into this house." and they drove us over. we didn't even go inside. we just looked and we thought, "oh, my goodness," you know, "this is amazing." >> reporter: there in his office he wrote his war stories and churned out sharp-elbowed columns on city politics for the local paper. stick in the eye stuff. he'd even been a losing candidate for mayor of durham. kathleen, meanwhile, was a top business exec at nortel, the telecommunications company. she'd received a master's degree in engineering from duke and had even appeared on the cover of a university magazine. >> she was a smart, smart woman.

but most of all, she was funny and sexual but had this marvelous sense of life and vitality just -- >> reporter: and you were in the swirl of the local society. right? >> yeah. >> reporter: charity balls and parties and nice dinners. >> yeah. and she did all of this. she -- >> reporter: good, smart friends at your table? >> absolutely. she would invite people over. she cooked meals. and she'd do the desserts. she did it all. >> reporter: so michael was all too happy to say yes when after years of living together, kathleen suggested the couple make it official. >> so we got married. and it was a gigantic wedding. it was in the house. and there must have been 150 people there. and it was just wonderful. >> i always thought, you know, "this is what i'll register as the happiest day of my life." >> reporter: kathleen's younger sister, candace, says kathleen was over the moon, as well. >> she was thrilled to be marrying michael. all three girls were bridesmaids in her wedding. i remember at the wedding the

three girls singing, "we're goin' to the chapel." the day they married, my sister glowed. >> reporter: and candace watched in amazement as, over the next several years, kathleen did it all. >> not only did she raise these children and have a quite accomplished corporate career, oh, dinner for 50? she'd do it. ♪ >> reporter: and so it was on that mild december evening 2001, with kathleen juggling it all. she'd been preparing for the holidays, while fending off the latest crisis at work. michael says she made dinner. they sat down to watch a movie. then, headed out back to enjoy a midnight glass of wine. >> we went to the pool, and we talked. >> reporter: what time would you guess? you're out there 10:00, 11:00 at night? >> well, this was at 11:00, 12:00, something -- something in there. >> reporter: with a morning conference call scheduled, michael says, kathleen turned in first. >> she said, "i gotta go in. i've gotta get ready. i gotta go to sleep be -- because the conference is first thing in the morning." so she gets up from the pool and goes, "i'll see you later."

>> reporter: an hour went by. maybe two. michael says he may have dozed off. when he went back inside the house sometime after 2:00 a.m., there was kathleen at the bottom of the stairs. a ghastly sight. >> and i saw her lying in the back staircase. her feet out. and there was blood. there was just blood everywhere. >> my wife's had an accident. she's still breathing. >> what kind of accident? >> she fell down the stairs. >> reporter: was she breathing? >> she was at the time. >> reporter: she was? >> yeah. >> is she conscious? >> what? >> is she conscious? >> no, she's not conscious. >> i knew she was dying. i mean, i'd seen enough of that in vietnam. i mean, i knew she was dying. >> please, get somebody here right away. please! >> okay, somebody's dispatching the ambulance. >> send the ems right away, right away, right away. called them again. how -- but apparently it's only, like, two minutes later. but it seemed like forever. >> reporter: a long few minutes, but nothing compared to the many, many years of questions

that would follow. what had happened on that back staircase now pooled in blood? >> the answer would be in the eye of the beholder. when we come back, what a husband called an accident an investigator would see very differently. >> i've seen falls. i've had family members fall. and to me, it did not look anywhere like a fall. ♪ nexgard chew

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emts saw michael cradling his wife, weeping so hard, he had to be pulled away. >> that was the worst. i mean, -- the worst. i mean, that was worse than anything in -- in war, anything, anything, because you expect that. this is entirely different. i had -- i wasn't ready for this at all, at all. >> did anything explain itself to you, michael? as you're looking at her crumpled -- >> she fell down the stairs. somebody's at the bottom of the stairs. your automatic response is, well, she fell down the stairs. >> detective art holland was called to the cedar street mansion in the wee hours. we first spoke to him more than a decade ago. >> so first officers had already arrived at the peterson house? >> right. first officers arrived. ems were -- arrived. >> reporter: the medical examiner was called in, too. he looked at the victim and said that a fall down the stairs was possible. >> he could see some lacerations or feel some of the lacerations on the back of mrs. peterson's head. and he stated that this could be the result of a fall.

>> reporter: by dawn, news of kathleen's fall started rippling through the family. details were still vague when family members reached michael's girls, margaret and martha, at college. >> she said -- um "something's happened." your mom has fallen down the stairs. you know it was an accident. you know, you should come home. >> reporter: by the time kathleen's daughter, caitlin, got the word, it was as shocking as it was definitive. her college roommate delivered the news. >> she looks me straight in my eye and she just says, "caitlin, it's your mom. she's dead." those words still ring clearly in my head. >> reporter: kathleen's sister, candace, couldn't believe what she was hearing. michael called her directly. >> it was still vague or she -- we couldn't tell if she fell down the stairs or she fell off a ladder, but there was no question i kept saying, "are you sure she's dead?" >> reporter: yes, michael was sure. candace headed to her sister's house. >> the whole thing was sealed off with crime scene tape. and this is a -- this is a mansion, huge property. so the police kept saying, you

know you may not want to go in. there's so much blood. this is really awesomely scary. >> reporter: the police were not exaggerating. when candace finally got inside, she says, michael brought her to the back staircase where it happened. >> my sister's blood is washed in pools up against the wall. i mean, her blood was everywhere. >> reporter: the image would be seared in her mind. it didn't look right. she couldn't go there. >> i still wanted to believe it was an accident. i didn't want to think something horrible happened. >> reporter: but all that blood, up the walls, could it all be from a fall down the stairs? and that's precisely what was gnawing at detective holland. >> i've seen falls. um i've had family members fall and to me it did not look anywhere like -- like a fall. >> reporter: something to him seemed off about kathleen's body position, too. >> her body was definitely not in the position that it would be in if she came to a final resting position after the fall.

>> reporter: they processed the scene, photographing the stairwell, documenting the pool of blood and spray up the wall. outside, drops on the walkway and a smear on the front door. in the kitchen, blood stains on a cabinet, and underneath, a drop of blood on the counter. and right beside it, an opened wine bottle and two glasses. >> it was, you know, very, very time consuming. you don't want to, you know, go through it real speedy. you want to make sure that you cross all your ts and dot all your is. >> reporter: it would take investigators a couple of days to go through the 9,000 square foot estate. while they did, michael and the kids took refuge at a neighbor's house. >> just spent most of the time in bed then -- margaret came in, martha, caitlin, everybody flew in, everybody. >> reporter: he says from the moment the police arrived at the house, they were aggressive towards him and his family. but even in his haze of shock and grief, peterson says, he thought he knew why.

>> i had written some really negative comments. i'd -- i'd been a columnist. and i've really, really been hammering the police. >> you -- you -- you lit out at the cops, huh? >> oh many times. >> reporter: his accusations of the city cops ranged from their failure to get a handle on drug trafficking to only solving a small fraction of crimes. >> the chief of police had emailed me just a couple days before saying, "mike, you don't know how much damage you've done to the morale in the police department," and all this. >> if you're seeing the cops giving you and the family some attitude, you think you understand why. >> that's what i thought. sure. sure. i understood it. yeah. of course, they're pissed at me. [ laughs ] i got -- i got it. >> reporter: but, he says, one of his sons read the police's behavior differently. he thought the police were zeroing in on his father from the get-go. >> he immediately called my brother, his uncle, who is an attorney in reno and said -- "uh uncle bill, kathleen's dead. they think mike did it." >> and my brother got on the phone. and he said, "i'm representing

michael peterson, do not talk to him." >> reporter: michael's daughters were also worried. they knew very well their father relished being the provocateur. and now the police were swarming their house. walking the yard. looking under bushes and trees. >> i remember feeling that something was going badly with the police. >> reporter: michael called a family meeting. >> he sat down with us and said, you know, "girls, i don't know what's going on, but it seems bad. and i -- i just want you to know i didn't do anything wrong. i didn't do anything." and we said, "of course, dad, we know." >> reporter: but police weren't so sure. they seemed intent on peeling away the veneer of the peterson's marriage. what was going on behind the closed doors in the mansion on cedar street? >> they were asking me questions about kathleen and michael's relationship. and if i knew of anything. i thought they were happily married. she was very much in love with him. >> reporter: but the detectives were beginning to believe the perfect marriage was anything but.

>> despite that gore journalists house -- gorgeous house, perhaps they i mean, you know, if he wasn't writing a book or had any royalties coming in, he had no income. >> i saw the seven huge lacerations that basically scalped her, she was murdered. that one picture. that was it. that one picture that was it.

>> reporter: michael peterson says he was certain that his wife, kathleen's death had been a terrible accident. a slip and fall down their back staircase after a night of drinking. but as days passed, he started to realize that not only did police think kathleen's death was a case of murder, but also that he was the prime suspect. >> well, that's just nonsense, and i wasn't worried because when you're innocent, well, nothing can happen. >> reporter: but it was hardly nonsense to detective holland of the durham police department. from the start, he was investigating not an accident but what he believed was a suspicious death. and there were good reasons, he felt, to take a close look at michael peterson. reasons, he says, that had nothing to do with peterson's very public criticism of the police. >> he may have had some issues with -- with the p.d. you know, i don't -- my perception of that is that i

don't -- i don't pay much attention to -- i -- i don't really like politics anyway. so therefore, it didn't affect me one way or the other. >> reporter: the detective wanted to know more about what was going on inside the peterson home. >> in addition to the forensic evidence you're gathering, you got to ask this question, "what's going on in this marriage?" huh? >> right. >> that's a big part of your investigation? >> right. >> reporter: detectives pulled aside kathleen's sister candace to ask if she'd noticed any trouble in her sister's marriage. >> the police took me in a police van to interview me privately. >> reporter: in her grief, candace was hesitant to say anything bad about her now widowed brother-in-law. she'd always liked him. >> he was a fun person to sit and chat with across a dinner table. he was interesting. he's a little bit arrogant about his intelligence, but you know he was a very smart man. when i found out my sister was dead, i was his biggest defender. >> reporter: she told investigators that everything was fine between michael and kathleen. it was only later as she started replaying conversations in her

head that she wondered if the couple had been fighting. kathleen certainly seemed stressed. >> she was very, very concerned about her job stability at her company. and they were making layoffs. >> reporter: according to candace, job insecurity couldn't have come at a worse time. her sister told her the financial pressures on their lives were mounting. she and michael were drowning in credit card debt. and that big house had turned into a money pit. and they'd invested heavily in her company's tech stock, only to lose a bundle when the dotcom bubble burst. then, there were the big college tuition bills. >> we've got three kids going to college, and good colleges, expensive private colleges. >> reporter: kathleen's daughter from her first marriage, caitlin, remembers it, too. >> there was a lot of financial problems. i sensed it. i sensed the stress of that. >> reporter: and when investigators looked at the couple's credit reports they saw just what kathleen's sister candace feared. >> it was living above their means.

i mean, you know, if he wasn't writing a book or had any royalties coming in, he had no income. >> reporter: and, according to kathleen's sister, michael's dabble in local politics had brought even more stress to the marriage. when he ran for mayor, he'd been called out publicly if a lie -- a whopper of one. the war action novelist claimed to have been awarded a purple heart, only he hadn't. he got hurt, not by taking hills in vietnam, but in a car accident in japan. >> when it became public about his lies, it did cause kathleen these friendships. she had to decide whether to stand by michael or keep these friendships, and these friendships were lost. >> reporter: so if the true state of the petersons' marriage was murky, investigators thought the story told in blood was becoming clear. not only was there more of it in the stairwell than detectives would expect to see with a fall, but according to emts, much of it was dry when they arrived. >> so you have to wonder when the victim actually goes down

those stairs. >> right, how long she'd been -- actually been there. >> reporter: a blood pattern expert analyzed the scene. when he completed his initial findings, police suspicions were confirmed. >> he told me that he felt strongly that, um, this was a homicide. >> can you tell us how this has been for you and your family? >> reporter: just a few days before christmas, michael peterson was charged with the murder of his wife. >> they had the grand jury, and, of course, i was indicted. and so, i turned myself in. >> reporter: as the officers booked michael into the county jail, the blended family formed a unified block of support. >> my mother would just be absolutely appalled, and this is the last thing she would ever, ever want to happen to her husband. >> reporter: it was hardly the christmas that the peterson family had so looked forward to. kathleen dead, their father in jail. >> it was just us kids, you know, in that house by ourselves, you know, trying to piece together a christmas.

>> reporter: but soon another bombshell, and this one would blow the family apart. two months after christmas, the coroner released the results of the official autopsy. >> multiple lacerations to the back of her head, it looked like she was bludgeoned to death. severe, long, linear lacerations. >> not consistent with a fall? >> not consistent with a fall. >> reporter: if kathleen's sister candace had been harboring suspicions about what had really happened to her sister, the medical examiner's report was the thing that pushed her over the edge. >> i saw the seven huge lacerations that basically scalped her, she was murdered. that one picture. that was it. >> reporter: after reading the autopsy report herself, kathleen's daughter caitlin agreed with her aunt. she called her step-sister, margaret. >> i said, "you need to read this. you need to understand that

mom -- she did not die from falling down stairs, that she was beaten to death." >> reporter: but caitlin's childhood playmates, her step-sisters margaret and martha, stood strong with their father. >> dad told me that he didn't do it, and i believe him. i trust him. >> reporter: the step-sisters never spoke again. caitlin removed her belongings from the house. >> i've lost, obviously, far more than just my mother. i thought, you know, i -- i did lose martha, and margaret, and michael, my family, my home. >> reporter: could the family agony get any worse? well, it could and by a wide margin because now investigators were picking through michael peterson's past, turning the clock back some 20 years, and taking a peek at his previous life an ocean away. what they would discover was beyond eerie. >> how can michael have found two women dead at the bottom of a staircase? coming up --

>> i go over to the house, and liz is dead. >> dead at the bottom of the stairs? >> bottom of the stairs. >> the story disturbingly familiar, and so were the suspicions. >> if you fell down the stairs, why would there be blood splurted up the side of the walls? it didn't make any sense to me. ♪ ♪ protect your pet with the #1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years. rudy got older and suddenly stopped eating...t, then we found freshpet. now rudy's 13, and going on 3. ♪ of non-drowsy claritin... and relief from symptoms caused by over... 200 outdoor and indoor allergens.

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>> reporter: in police work, a good tip can make your day and also make your life a lot more complicated. just such a tip came to the desk of the detective working the kathleen peterson case. >> i think it was two or three days after kathleen's death is when i first had contact with um the family members of elizabeth ratliff. >> reporter: and just who was elizabeth ratliff? to answer that question we have to turn the clock back almost twenty years in michael peterson's life and go across the atlantic to germany. in the early 1980's, michael peterson was living with his first wife near a u.s. air force base outside frankfurt. their good friend, elizabeth ratliff, a widow, lived nearby. >> liz has two children. and she's teaching school, has a great many friends who are, you know, all there. >> reporter: on november 24th,

1985, elizabeth went to the petersons for dinner. later, michael peterson says he drove her home. >> she got out and went upstairs. i said, "night, liz, you know, see you tomorrow." >> reporter: the next morning, michael says he was fast asleep when elizabeth's nanny came running with urgent news. >> i'm upstairs in bed. and she's saying something that, in fact, you know, liz is dead or hurt or i don't know. she's screaming. and so i put some clothes on. and i go over to the house. and, in fact, liz is dead. >> reporter: dead at the bottom of the stairs. >> bottom of the stairs. >> reporter: another good friend in their circle, amybeth berner and her husband, were summoned to elizabeth's townhouse, too. she asked michael what happened. >> he said, "well, she probably had an aneurysm like her father." when i thought about someone falling down the stairs i thought, well, that's possible. those stairs are, you know, pretty steep and, you know, they're slippery and wooden. >> reporter: but amybeth says as

she looked around she noticed something. blood not just where elizabeth lay, but high up along the staircase walls, too. too much blood, she thought, for a slip and fall. >> if you fell down the stairs, why would there be blood splurted up the side of the walls?" it didn't make any sense to me. >> reporter: and she says there were household details out of order: like the table that liz set out every night with the girls' breakfast plates. it was bare. the snow boots she routinely left by the front door, still on her feet. >> liz never wore her boots in the house. she'd always took her boots off. and that was another clue to me that something was wrong. it's obvious that she was either running from someone or trying to escape. >> reporter: amybeth thought a full-fledged investigation would ensue. but, as she tells it, michael peterson spoke to the authorities that day, relating that elizabeth had a hereditary bleeding disorder. perhaps she'd had a stroke and fallen down the stairs.

the questions amybeth expected to be asked never were. >> i wondered, you know, "why aren't they talking to people? why aren't they asking questions?" no one did. >> reporter: later that day, michael peterson phoned elizabeth ratliff's family in the u.s. with the dreadful news. margaret blair is elizabeth's sister. >> he said "um margaret, there's been an accident. liz fell down the stairs and died." "what are you saying?" i just totally went numb. i mean, my sister. he's saying she died. she's young. she's got two beautiful little children. babies, really. >> reporter: those baby girls? they are martha and margaret. michael took custody of the girls after the accident in germany. and then michael, along with his first wife patty, and then later with kathleen, raised them as his own. >> patty was saying that our birth mother was like a sister to her. she was her closest friend in the whole world. and it was said in our mother's will that we would go to mike

and patty when they passed away. and, so, dad saw it as his responsibility and took us in. and stay -- we stayed with him for our whole lives. >> reporter: you didn't think, "that's strange, the petersons? who are these people? >> well actually, you know, i can understand how that could happen. this was her world now. liz must love these people and trusted them to the nth degree. >> reporter: elizabeth ratliff's body was flown to texas for burial. at the funeral, margaret was desperate to hear further details from michael peterson about her sister's passing. but to her surprise -- >> michael was very aloof and very strange. >> reporter: did he speak? >> no, he didn't really say a lot at all. he never talked about the -- what happened to liz. >> reporter: but any questions regarding foul play in elizabeth ratliff's death were laid to rest by the results of an autopsy performed at the u.s. military hospital in germany. elizabeth died, the examiner said, from a brain hemorrhage,

natural causes. so the story lay buried for nearly two decades. but when detective art holland heard it, his head spun. >> i was overwhelmed with, you know, here i have two women that appeared to die the same way. two women that are associated with michael peterson. >> reporter: detectives wanted to dig a little deeper. what would they find? coming up -- for investigators, a risky move. >> a lot of people were very antsy about that. >> will it pay off? >> i'm just thinking that my >> i'm just thinking that my case is getting a whole lot better. what patients don't realize is what they eat and drink is likely acidic and then what's happening is the weakening of enamel. now is the perfect time for a toothpaste like the new pronamel repair. this toothpaste takes it to the next level.

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>> reporter: as time went by, margaret blair had come to accept michael peterson's explanation of her sister's death years before, a tumble down the stairs in a german townhouse. >> i just believed what i was told about the cerebral hemorrhage and, you know, i'm presuming that a doctor had, you know, made this diagnosis. >> reporter: but when she learned that kathleen had also been found dead at the bottom of a staircase, margaret began wondering anew about how her sister died. she started reaching out elizabeth's old friends from germany. >> when i talked to her friends,

i found out that blood had been dripping down the walls. well, that doesn't happen when you have a cerebral hemorrhage. >> reporter: authorities in north carolina were thinking the same thing. if foul play had been involved in elizabeth ratliff's death, it might bolster their case. but the only way to know for sure, they concluded, was to dig up elizabeth's grave. assistant district attorney freda black. >> we decided that it probably would be worthwhile to try to exhume her body to determine whether the findings in germany were accurate or not. >> reporter: to do that, they'd have to get the okay from elizabeth's daughters, margaret and martha. the girls, who believed in their father's innocence as fiercely as they mistrusted the authorities, struggled with the decision. >> the hardest thing i've ever had to do was to write off on the exhumation of our birth mother. >> reporter: but ultimately, they agreed. >> and i signed off on it because we wanted to be, like, "there is no way this could've

happened." like, please look at the evidence. i will do this to -- to free our dad of these accusations. >> reporter: on a beautiful blue sky day, the remains of elizabeth ratliff were exhumed from their resting place in texas. >> ratliff's bodies -- >> reporter: julia sims, of nbc's raleigh-durham affiliate, wral-tv, has been covering the story since the beginning. >> and the bells started tolling right as they started pulling that casket out of the -- the ground. >> hmm. >> a lot of people were very antsy about that, about what they were gonna find. >> reporter: her body was driven to north carolina where it would be studied by the same medical examiner who'd ruled kathleen peterson's death a homicide. >> there was a risk here wasn't there? if you opened that coffin and found that the authorities in germany had been correct in ruling it a death by natural causes. >> we just decided that it needed to be done. >> roll the dice, basically. >> exactly. >> reporter: the detective peered through a morgue window

as the top was pried off elizabeth ratliff's coffin. >> it was so airtight it was hard to use the crank to get the casket to open. once it was raised you could see part of elizabeth ratliff's face and hair. it was remarkable. >> reporter: they were stunned. the body was practically intact. >> her fingernail polish was still on. her dress was still perfectly in place. >> reporter: the m.e. took a closer look at the injuries to elizabeth's head. she was finding lacerations, deep gouges in the scalp. seven of them. >> seven lacerations. you could -- black: it was amazing -- >> count them. >> it was uncanny. the lacerations were very similar to the ones that had been perpetrated upon kathleen peterson. and in her findings, she made a decision that ms. ratliff had been -- had been murdered. >> reporter: investigators thought they'd hit pay dirt. in death, they thought kathleen peterson and elizabeth ratliff could have been twins.

>> i'm just thinking that, that my case is getting a whole lot better. >> reporter: kathleen's sister candace thought that peterson had killed both women. >> i have a better chance of being struck by lightning than finding two people who i intimately know at the bottom of a staircase. >> reporter: but to martha and margaret, the whole thing seemed absurd. the fact that michael was being accused of killing kathleen, the woman they called mom, was bizarre enough. but now, their birth mom, too? what would their father have gained by killing elizabeth ratliff? >> he would've gotten two screaming little ragamuffin kids out of it and that's it? like, there's nothing -- there's no reason for it. >> reporter: for the investigators in north carolina, though, the death in germany became a strong building block in their circumstantial case for murder. and what's more -- detectives learned that michael peterson had a secret life. secrets -- tawdry ones -- were about to spill out in the durham courthouse.

coming up -- enter brad, the male escort. >> what types of services did you perform? >> oh, wow. that's -- that's pretty broad. >> and the individual wearing these pants at time of that impact was in close proximity to the source of blood when it was impacted. >> i remember the jurors were captivated by his testimony. um, and it all seemed to make perfect sense. ll seemed to make perfect sense. ♪ ♪ nexgard chew comes the confidence you're doing what's right to protect your dog from fleas and ticks for a full month. and it's the only chew fda approved to prevent infections that cause lyme disease. nexgard. what one little chew can do.

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>> reporter: in the summer of 2003, michael peterson would stand trial for the bludgeoning death of his wife, kathleen. he'd pleaded not guilty to first-degree murder. >> i am innocent of these charges, and we will prove it in court.

>> reporter: with gavel-to-gavel coverage on live tv, the state versus michael peterson was a national spectacle. >> was it surreal, michael, to be in a courtroom charged with murder? >> well, it was surreal from the first moment. i mean, you know, is there surreal beyond surreal? i don't know. >> reporter: reporter julia sims covered the proceedings in court. >> every single day of that trial the courtroom was packed, and not packed with just media, and not packed with just lawyers, but people off the street. people took vacation to come in and watch that trial. >> reporter: and michael peterson didn't shy away from all the attention. in fact, he allowed a documentary crew to film him every step of the way. but the only audience that mattered was the 12-person jury. and when the trial began, the prosecution introduced them to the man behind the professorial mask, the person they saw as the real michael peterson. >> this case is about pretense and appearances. it's about things not being as

they seem. >> reporter: scratch beneath the glossy veneer, the beautiful house and sparkling dinner parties, and prosecutors would tell the jury they'd find a marriage in shambles. more than the couple's money problems, more than the loss of social standing after michael got caught out lying about his military record, there was what investigators found when they searched his home office. >> it was just so -- so different than what everybody that knew michael peterson believed him to be, as far as a family man, a happily married man. it was jaw dropping. >> reporter: while kathleen toiled away at her executive job to pay the couple's mounting bills, michael's writing career was hitting a wall. >> he had some free time on his hands. and we believed that he, somewhere along the way, began to form relationships, let's say, with men that he particularly met on the computer. >> reporter: not women, but men. the prosecution's theory was this -- the night kathleen died, she went into michael's office to

retrieve an email about that work conference call the next morning. there in his office, the prosecutors believe, she stumbled upon e-mail exchanges between her husband and an escort. >> the e-mails were very specific about what they had planned on doing and what they wanted to do with each other. >> reporter: very graphic, steamy stuff? >> they were. >> reporter: the escort's user name? "soldiertop brad." his website pic was a come-hither beefcake pose complete with dog tags. "you have great reviews and i would like to get together" peterson wrote in one e-mail. "i've never done escort but used to pay to blank a super macho guy who played lacrosse." "i'm very bi, and that's all there is to it." >> what type of services did you perform? >> oh wow, that's pretty broad. >> reporter: in a sensational revelation, the prosecution called brad the escort to the stand. >> what type of sexual activities, sir? >> oh, just about anything under the sun. >> reporter: on the witness stand, the escort told the jury that just three-months before kathleen's death, he and michael

peterson had arranged to meet. >> we were to hook up. >> and what were you all planning on doing? >> having sex. >> reporter: the hookup never happened, but combine that with the other combustibles in the couple's life, the prosecution said, and you have all the ingredients for a fatal confrontation. >> it got out of control, and michael peterson snapped. and he was the only one who could have done it, according to the prosecution. >> reporter: further evidence that michael attacked kathleen ferociously, the prosecution stated, was as clear as the spray of blood up the staircase walls. >> the amount of blood, the positioning of the blood, the location of the blood, it was overwhelming. >> in general terms, the greater the force, the smaller the drop. >> reporter: to take the jury vividly up the back stairs, the prosecution called the state's blood pattern expert, duane deaver. he told the jury with certainty that kathleen peterson had been beaten to death. he testified the droplet pattern high up the walls was just what you'd expect to see with a

weapon rising, striking, and casting off blood with each new blow. >> and i believe there is a minimum of four blows that have occurred in this, uh -- in this scene. >> reporter: what's more, deaver testified, this blood stain was found on the inside of peterson's shorts. he'd done tests that he says proved that the only way it could have gotten there was if peterson had been standing over his wife, beating her. >> and the individual wearing these pants at time of that impact was in close proximity to the source of blood when it was impacted. >> i remember the jurors were captivated by his testimony. um, and it all seemed to make perfect sense. >> reporter: then there was all that dried blood the emts noticed around kathleen's body, suggesting she may have been attacked well before peterson called 9-1-1. according to prosecutors, lab tests backed that up. kathleen's head injuries had produced something called red neurons, which they say form

after oxygen is withheld from the brain for at least two hours. >> that gives mr. peterson at least two hours to do things before the 9-1-1 call is placed. >> reporter: what was he doing during all that time? the state argued he was staging the scene. detectives saw what they thought were wipe marks on the stairs. to them, it was an attempt at a clean up. and there were those two wine glasses on the kitchen counter suggesting an evening of maybe too much drink, followed by a tumble down the stairs. thing was, kathleen's fingerprints weren't on either glass. in fact, the prosecution said, kathleen's blood-alcohol content was low enough that she could have passed a roadside breathalyzer test. >> she wasn't drunk. she wasn't intoxicated. um, she did have a little in her system. but not enough, arguably, to have caused her to not be able to walk up stairs. >> reporter: was the writer of fiction, making up yet another story, covering up murder as an accident?

coming up -- michael peterson speaks out about it all, including his interest in sex with men. he says others knew all about it. this is not a family secret? >> no, it's not. >> and then why he thinks kathleen most likely fell after a recent injury he says she was on major meds. do you remember her being wobbly? >> oh, my god, yeah. ♪ nexgard chew comes the confidence you're doing what's right to protect your dog from fleas and ticks for a full month. it's the #1 vet recommended protection. and it's safe for puppies. nexgard. what one little chew can do.

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