of course we will see you back here next friday night on "unguarded." good night. -- captions by vitac -- www.vitac.com an employee from a large brokerage firm disappeared. her computer revealed she was leading a double life. among the bits and bytes were the clues to her final destination. to friends and family, 36-year-old sherry durall had an enviable life. married with three young children, sherry had a high-paying job with a stock brokerage firm and the respect and admiration of her colleagues.

>> she was selfless. she was warm. she also did things for other people. she cared about others a lot. >> sherry was also a punctual employee, so when she didn't come to work one day and didn't call, her co-workers were concerned. they called her husband, bob, who said sherry left for work at the usual time that morning and he didn't know where she was. so sherry's friends called police. >> a couple of officers look around, knock on the door and nobody answers, but they find an unlocked door. so they go in the house, they walk through the house, everything looks orderly and everything looks tidy. >> sherry's clothes, jewelry and toiletries were still in the house. >> it seemed very unusual that a woman with three children would just suddenly disappear. >> for the next two days, there were no signs of her.

then police got a call about a red van driving erratically. the license plate number identified the van as sherry durall's. >> the witness said it was weaving in and out of traffic. slowing down and speeding up, to a point where he wouldn't let the witness pass him. >> unfortunately, the witness didn't get a good look at who was driving the van. friends distributed missing person flyers throughout the community and a convenience store clerk responded, saying that sherry was in his store the day after she disappeared. >> the clerk there was sure that she'd seen her on saturday evening and came in and purchased gas with cash and then left. there was an initial thought that, yeah, she is in the area and the van has been seen traveling along the freeway. >> sherry's husband looked around their home for clues and

found some information on sherry's computer that he turned over to the police. >> we investigated that and discovered that mrs.?durall had, in fact, pursued a relationship outside her marriage. >> there were e-mails, and internet chat room conversations with a man named kevin johnson. and it was clear, the relationship was serious. >> i have tried to be indifferent to you and keep my feelings in check. i have been thinking about this a lot and feeling bad about my self-respect, sort of feeling like a call girl more than a friend. >> the correspondence included talk of the two running away together. >> they talked about, wouldn't it be great to go to costa rica? the cost of living there is so much cheaper. >> when police interviewed kevin johnson, he admitted the two had a brief affair, but insisted he hadn't seen her for the last six

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one week had passed since

sherry durall's disappearance. she hadn't contacted her children, her husband or kevin johnson, the man with whom she had the affair. >> i knew that she wouldn't leave without telling her mom or calling me. we're the two closest people to her. she was too responsible of a mother and a person to do that. >> then investigators got their first solid lead. they found sherry's van in a hotel parking lot near the seattle airport. >> that could have been a thought that she parked there or she met somebody who came into town or she hopped on a plane and took off. >> but there was no record she stayed in the hotel or took a flight out of town. >> it was very emotional, finding that van and not her. she wasn't anywhere near the

vehicle, and so we found a van, but we didn't find our friend. and that was really difficult. >> a forensic examination of the van revealed no evidence of foul play and there were no foreign fingerprints. even more troubling, sherry's personal bank account hadn't been touched since her disappearance. >> she just got a bonus at work, and she had just put that into the bank, i think, that week. so the theory from all the co-workers was why would she be putting all this money away and not leave with it, not touch it? >> police conducted extensive interviews with sherry's friend, kevin johnson. he insisted he had nothing to do with her disappearance. >> and he was later able to provide some information, what he was doing on the day she was reported missing. >> sherry's co-workers told

police about a comment she made the day before she disappeared. >> she said if anything happens to me, my life is in my desk. and in her desk, among other things, was a long letter, a draft of a letter she had written to her husband in an effort to try to explain why she felt it necessary to leave him. >> "my spirit is crushed. i feel that you are too controlling and obsessive and jealous, and i just can't live with those personality traits anymore. i can't go on pretending that there is nothing wrong. i am unbearably unhappy. the bottom line is i don't love you enough to stay married." >> also in her desk were books about divorce. >> she was planning the separation, and she had saved up some money and she had spoke to a couple of lawyers to get some advice. and she was making her plans to move on to her new life with her children. >> and sherry told friends that

bob had been abusive. >> no sign of physical violence at all. it was more that she wasn't comfortable around him. he was obsessive, controlling. he emotionally controlled her, and she just did not feel good around him. >> he would apparently be sort of monitoring her whereabouts. occasionally, she would go to lunch with some of her friends. mr. durall would show up. so he, in effect -- she describes the situation where you almost have a husband stalking his own wife. >> during police questioning, bob durall admitted there were problems in his marriage. as for him being involved in sherry's disappearance, he said that was ridiculous. police asked bob what happened on the night before she disappeared. bob said they went to dinner at a local restaurant. when they got home, sherry spoke with her sister-in-law. >> mrs. durall appeared perhaps

slightly tipsy and told her that she was going to bed and that her husband, robert durall, had made her a drink. >> sherry's sister-in-law told police that she was very suspicious because bob seldom served his wife. usually, it was the other way around. >> they said that it was extraordinarily atypical for mr. durall to ever make his wife a drink of any kind or to serve her any kind of food or drink. >> and sherry's best friend had one final insight. it was a dream she had about sherry the night before she disappeared. >> i woke my husband up like at 12:30, 1:00 in the morning, and i said, oh, i had the worst dream about blood everywhere and couldn't get back to sleep. and i feel like that was a

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the information found in sherry durall's desk at work painted a revealing picture of her marriage at the time of her disappearance. so investigators decided to

search bob durall's work computer, too. bob was in charge of the computer system at the king county housing authority. as a government agency, bob's computer was government property. so investigators seized it and turned it over to gordon mitchell, an expert in the growing field of computer forensics. mitchell copied bob durall's hard drive to examine the information on it without altering the original data. >> this is an important process where they can actually discover is there something going on here or is bob just a nice guy? >> mitchell found evidence that bob deleted certain files, but they were still on the hard drive. that's because computers don't erase files. they just mark the space occupied by those files for reuse. >> a lot of the deleted files

are simply information left in place. >> the deleted information revealed that bob was dating women he met on the online dating service match.com, and was doing so at the same time his wife, sherry, was dating kevin johnson. bob's profile on the dating website was also revealing. >> mr. durall portrayed himself as a man who was living separately from his wife and who was completely unburdened by any other romantic or personal attachments and was open to a relationship with the appropriate woman. >> in e-mails to prospective dates, bob explained why a divorce was impossible. >> to one young woman, mr. durall said that he really did not want to pursue a divorce with his wife because it would be expensive and messy. he actually went so far as to say he would be better off if

his wife were dead. >> in another e-mail, bob said he had a plan to resolve his unsatisfactory marriage. bob's internet search engine revealed he looked for information on all sorts of diabolical schemes. >> we were shocked to see these searches on things like poison, herbs, death, something about sedation of people, also about smothering. but the most graphic one was actually a search that durall did on the words "kill spouse." >> investigators now had probable cause to search the durall's home, and they went straight to the master bedroom. they found a spot on the carpet that looked like it had been cleaned. they swabbed it with phenolphthalein and it turned purple, an indication it was blood.

under the bed were two squares of carpet that had been cut out and replaced. underneath were large pools of blood that had been cleaned with water and detergents. around the bed, almost invisible to the naked eye, investigators found the most incriminating evidence. >> it was just hundreds and hundreds of very, very small red dots on the headboard, on the wall, above the headboard, in the corners and on the bureau and on the doorjamb to the bathroom. >> the blood near the floor didn't happen during the beating. >> that's blood just coughing out of the lungs through the mouth. and that was done very low to the ground. so someone was coughing up blood very close to the ground in the area where this large pool of blood underneath the bed had been.

>> investigators concluded that the blood on the walls and ceiling was medium-velocity blood spatter, consistent with someone swinging a bloody object. scientists compared the dna from the blood in the bedroom to the dna profiles of sherry's parents and discovered that this was sherry's blood. investigators also found a bloodstain on the doorway leading to the garage. and in bob's car was the receipt for a specialty cleaning product. and police also solved another mystery. where were the duralls' children on the night of the murder? >> a perfect opportunity for

him. his youngest child was going to be gone that evening. his other two were at camp, and they were going to be alone in the house that night. >> giving bob all night to carry out his plan. but where was her body? how are things with the new guy? all we do is go out to dinner. that's it? i mean, he picks up the tab every time, which is great...what? he's using you. he probably has a citi thankyou card and gets 2x the points at restaurants. so he's just racking up points with me.

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41-year-old bob durall sat in prison awaiting trial for his wife's murder. to police, he denied it, but to

his god, he said something else. >> in a jail cell, he was observed and overheard apparently asking god to forgive him for what he had done. >> prosecutors didn't need to find sherry's body in order to go to trial. no one could have survived the amount of blood loss found in sherry's bedroom. but for the sake of her family, prosecutors approached bob durall's attorneys with an offer. >> we said we would encourage mr. durall to lead us to the location of the body of his wife, and that we would not use evidence that he had revealed the whereabouts at trial. >> surprisingly, bob agreed and led investigators to the cascade mountains, about an hour's drive away. there, at the base of a steep ravine, they found sherry's body in a plastic bag under a pile of rocks.

the autopsy revealed sherry died of blunt force trauma, just as the forensic evidence suggested. prosecutors believed bob was as unhappy in the marriage as sherry was, but concluded a divorce would be too expensive. >> he did not want to incur the costs of child support or of a divorce and division of the property. mrs. durall's parents were fairly wealthy. mr. durall didn't want to lose his inheritance. >> on the night of the crime, prosecutors think bob drugged sherry to make her drowsy, although toxicology tests at the autopsy were inconclusive. the evidence proves bob hit sherry on the head repeatedly with a blunt object, creating

the blood spatter on the floor, walls and ceiling. bob wrapped her body in plastic, then carried her body to the garage, leaving the blood smear on the door. he dumped her body in the ravine near the cascade mountains, and returned home to clean up the crime scene. the evidence shows that bob tried to clean up the blood in the bedroom, but couldn't come close to removing it all. >> so you have got a guy who fancies himself an extraordinarily clever and crafty fellow, who has done months of research on how to commit a murder, and then he commits a mistake that a sixth grader would laugh at. so he is a very peculiar man, a very dangerous man. in some ways, he was his own worst enemy.

>> police think it was bob driving sherry's van to the hotel parking lot when the witness reported seeing it. and they think the store clerk was simply mistaken when he claimed sherry was in his store the day after her disappearance. >> we pulled the videotape from the store that evening, and sherry was nowhere on the tape. >> at bob durall's trial, despite leading police to sherry's body, he pled not guilty and took the stand in his own defense. he told an incredible tale of two men who killed sherry and forced him to dispose of her body. they said they'd kill him and the children if he went to the police. >> actually, i was having a hard time trying not to laugh, because i thought it was so ridiculous of a story, that after two years in jail, you think he would come up with a

better -- a better story. but in reality, i think that he was putting half the story together during the trial. >> in the end, there was simply too much forensic evidence. the computer forensics and blood spatter told the story. after only two hours of deliberation, bob durall was found guilty of first-degree murder and sentenced to 46 years in prison. >> i will impose a total of 560 months. >> despite spending months researching and planning his wife's murder, he still wasn't able to get away with it. >> i think the forensic evidence was everything, the direction of the blood, the patterns, how they went out around the room. >> like in many cases, the evidence was really overwhelming. not just a single thing, but many, many items that helped us feel confident about what we were doing. >> mr. durall, who was professionally involved in the

use of computers, the extent to which he left evidence of premeditated murder on his work computer in such a sort of blatant way really continues to boggle my mind. there were lots of suspects in the murder of a millionaire oil man and many salivating over the man's estate, and that fact alone helped crack the case. ron and rosana shaw had just moved into their luxurious, new home in youngsville, louisiana, but they still had some things to do before the birth of their new baby. on this night, ron helped his