Announcer: "20/20" Saturday continues with "Sleeping with the enemy." Here again, John eknoquinones. Reporter: On the evening of August 26th, 2005, raven abaroa says he comes home to make a shocking... See More
Announcer: "20/20" Saturday continues with "Sleeping with the enemy." Here again, John eknoquinones. Reporter: On the evening of August 26th, 2005, raven abaroa says he comes home to make a shocking discovery. His wife, Janet, bleeding on the floor. Durham 911, where is your emergency? I'm at home. My wife -- she's dead! There's blood everywhere. Reporter: Police and E.M.S. Respond, but they arrive too late. Just before 11:00 Tuesday night, Durham police are called to this Ferrand drive home. When they arrive they find 25-year-old Janet abroa murdered. Police aren't saying how she was killed. And the sight of police tape and investigators in this normally quiet neighborhood came as a shock. Reporter: Early the next morning Janet's parents are awakened by a phone call. It's raven. He was calling to tell them that Janet was dead, and she had committed suicide. We automatically knew that was not right. She wouldn't have done that to Kaiden. She never would have killed herself, ever. We knew that wasn't true. Reporter: In fact, police quickly realize raven's claim of suicide is flat out wrong. Janet has been murdered, and not with a gun. She's been stabbed to death. Cathy cheek and Janet were co-workers and close friends. That same day she turns on the morning news. Hours after the discovery the body of the young woman was removed from the home. Reporter: She races to Janet's home on Ferrand drive. I got there. Saw the yellow crime lab tape. I was thinking maybe it's not this house, maybe it's next door. But it was her house. A little tiny blond-headed girl that's dead. I didn't want it to be her, but it was. Reporter: Crime scene investigators find a bloody footprint and an unidentified fingerprint. Raven also reports his laptop and a knife have gone missing. Was this a robbery gone bad? Janet's murder is the talk of the town. Janet abaroa was found inside her Ferrand drive home last -- -- With appeared to be a stab wound in her chest. Reporter: But nobody has any answers. Police inspect all the windows and doors in Janet's home and find no sign of forced entry or a break-in. We'd like anybody that has any information to call us, no matter how insignificant they think it is. Reporter: In an outpouring of Greif, Janet's family hosts a vigil in downtown Durham. Purple ribbons, Janet's favorite color, are worn, candles are lit, and hymns are sung. Janet's family and friends are desperate to find out what happened to Janet. Raven, on the other hand, not so much. I kept talking to raven. "You've got to help solve this case." Reporter: Tim dowd is shocked when only four days after the murder, raven leaves town, taking Kaiden. They go to his boyhood home outside Salt Lake City. Is it too painful for him to stay? Or is he running? My thought is, if somebody were to murder my wife or a child, or any close family member of mine, I'm banging on the police door saying, "What have you done lately?" Raven did nothing. He left, and never came back, with the exception of sneaking into ton once to pick up his furniture, and he left. He hasn't helped the police. He hasn't, like, set out a reward of, you know, help me find my wife's killer. Raven provided cooperation at the beginning of the investigation, but there've been subsequent requests for interviews that have gone unanswered. Reporter: Police would like to ask raven some questions, especially about the knife that went missing the night Janet was killed. Remember that Christmas video? With Janet in the background, raven weirdly brags about a brand-new knife for his collection. That's my new knife. I got it for Christmas, thank you, I bought myself. My dad would be very proud. I like to collect knives. Reporter: But could someone else have used one of raven's knives to stab Janet? The bloody footprint and fingerprint at the crime scene don't match raven. Janet's sisters start playing detective. The amateur sleuths uncover several things that don't add up. He said it was an intruder. Raven said it was a break-in. The detectives didn't say it was a break-in. There were no signs of a break-in. There was no signs of an intruder. No signs of a struggle. I said, "No way." There is no way that somebody came into her home because I know Janet's habits. Number one, she always locked the door. Number two, there was no broken glass or anything like that, so it wasn't an intruder. Reporter: The sisters might not have experience in criminal law, but Nancy grace does, and she doesn't buy the intruder story either. There is no forced entry. There is no sign of struggle. There is no sex attack. There is no robbery for anything of value. Her rings are still sitting there by the sink. This is what was missing -- some of his beloved knife collection. His wife was stabbed to death. And his laptop. Reporter: The sisters also uncover a possible motive. He had taken out a life insurance policy soon after she was pregnant with Kaiden. Reporter: How much was the policy? $500,000. Reporter: Is he capable of doing that? Doing it for the insurance money? Absolutely. Reporter: Any doubt in your minds that raven killed your sister? All: No. Reporter: And Kaiden, the baby, was in the next room. Uh-huh. Yup. Reporter: How could a father do this? Someone who's very self-absorbed with no conscience. It's all about him. It's not about Janet, and it's not about Kaiden. It's about him and his needs and his wants at that point. Reporter: The abaroa's old neighbor, Tim dowd, is also studying every detail of the case. It all points to one, and only one, place, and that's raven abaroa. And I, it tears me up to say that 'cause I looked at him at one point in my life as a son. He was on the inner circle of our family. You know, and that's a -- that's pretty shocking. And it was hard for me to come to that realization, but I had no other alternative. Everything points back to raven. Reporter: But opinions of grieving family and friends are not enough to make an arrest for murder. Without new evidence that will hold up in court, police have nowhere to go. We would obviously like to talk to raven. He hasn't been ruled out as a person of interest. But it's still an open investigation. Reporter: Raven may have stopped talking to police, but he's not keeping his mouth shut. He makes his case for the court of public opinion on a local TV show. I wasn't off involved with the death of my life. That I would do anything in the world to keep her here with me and that's just -- that's something I know and I think that's something the people who truly know Janet and truly know me can understand and appreciate. Reporter: Was raven innocent? Could the murderer be a stranger who left a bloody footprint? Or is raven a killer on the loose, out in Utah, now a smiling bachelor with a new woman in his life. Did he mention his ex-wife? Yes, as we were just starting to date. Reporter: Did he say she was murdered? See what happens next.
This transcript has been automatically generated and may not be 100% accurate.