Announcer: "20/20" Saturday continues with "Sleeping with the enemy." Here again John Quinones. Reporter: In the weeks before she was murdered, Janet was keeping a secret from all but her closest... See More
Announcer: "20/20" Saturday continues with "Sleeping with the enemy." Here again John Quinones. Reporter: In the weeks before she was murdered, Janet was keeping a secret from all but her closest family and friends. She was pregnant with her second child, a girl. She also died that night. I did not know that she was pregnant. She did not tell us. It wasn't just the issue of killing his wife, Janet. There was the unborn child that he slaughtered, slaughtered and left there to die along with his wife, the mother of his child, the unborn child who never had a chance. Why? Reporter: Cathy cheek says Janet came to her for advice. She went to the doctor. She cried and said it wasn't going to be good, raven wasn't going to be happy that she was pregnant because he didn't want a child at that time. Reporter: The trail starts here. They draw a straight line from the abaroa's money problems to Janet's pregnancy to that life insurance policy. He is used to living high on the hog. He is used to stealing, getting his money. He is not used to having to struggle for money. It's not just financial problems. It's called greed. "I need more greed." Then you got insurance. He couldn't afford anything else, but he kept paying that. He was biding his time, he was waiting. Problem with that is Janet got pregnant again. I think that raven thought that the grass was going to be greener on the other side of the fence. And I think what raven saw is thability to collect this money. Reporter: Next, the state presents evidence they believe shows raven carefully planned his alibi and crafted the home robbery story. Janet's sister Sonja says raven and Kaiden stayed with her shortly after Janet's murder. She found his behavior strange. I felt like he wasn't fully cooperating with the detectives so I went through his belongings. Reporter: Remember raven reported his laptop stolen. Sonja says when raven was out, she looked in his bag and found several computer disks. I looked at the disks on the computer, one of the disks appeared to be a backup of his hard drive. On the outside of the disks they were dated 4/25/05, which was the day before her murder. All the files had modified date, 4/25/05, which, like I said, was alarming to me because one of the things the detective first told us was they didn't believe it was a break-in because the only thing missing was his laptop and knives. He downloads, backs up all of his files off of his laptop onto disks just hours before his laptop is "Stolen" and his wife is murdered by an "Intruder." Reporter: For the state, this is yet another piece of the mosaic showing raven planning the murder 24 hours prior. That's how he spent his day, ladies and gentlemen, on April 25th, 2005, dropping and dragging so he could get everything on that disk. He knew what he was going to do. He knew what was going to happen. He knew what he was going to do the next day. He couldn't lose his computer stuff. So he backed up his computer stuff. Reporter: The day of the murder raven says he took off from work. He spends the day watching Kaiden and running errands. But before he left for his soccer game that night, he did something he never did before. He locks the two family guard dogs in the shed. Do you know whether they stayed inside or outside? Janet said they stayed inside. She said while raven was away at games she liked to keep him in the house because she felt protected. Reporter: The dogs always spent the night here, in the crates under the kitchen counter. It's another inconsistency in raven's behavior. The dogs. At night those dogs are inside in a kennel. Why was this night so much different than the others? Because he was going to murder her. Reporter: Raven told detective Benny Bradley, the first homicide investigator to work the case, that his soccer game started at 9:00 P.M. The field is a half-hour drive from his house. Raven indicate he got to the game location with just enough time to warm up before the game started. He indicated the game lasted an hour. After the game he left the sports arena and only made one stop before he arriving home, and the purpose of the stop was to buy Gatorade. Reporter: Detective Bradley interviewed several players who said raven was at the game. He also pulled surveillance video from the convenience store that proves raven did stop to buy a drink. But detective sole thinks that video is more proof of raven's planning. Remember those phone conversations he had with raven? He tells me in a phone conversation, "Well, you knew where I was at, you know, afterward because I went to the gas station, and it was video'd." And I am saying to myself, "Well, where would you have known that?" Again, I go back to the staging. He's a smart enough to know he has got to document where he is at. He can't have gaps from when he gets to the soccer game and when he leaves. That he has to account for this time so he is documenting that. Reporter: But with all that planning, raven still made one huge mistake. When he first spoke to police, he said Janet was dead when he found her. He said once he entered the residence he made his way down the hall toward the master bedroom and the office. He stated that he saw Janet's eyes were open and her lips were blue. Reporter: Now, listen to what he told Mike Guzman, an advisor from the church who rushed to raven's side just hours after the murder. He said he came home and went upstairs and found Janet on the floor and he immediately grabbed her. I believe he said to me that she had asked him, "Why do I hurt so bad?" And his response was, "I don't know." The jury, when they heard that, they were shocked. I mean, they were shocked. In a conversation, you know, five or six or eight hours afterwards, he tells Guzman that Janet says to him, "Why does this hurt so much?" And it's like, how could Janet say that, because you said when you found her, she was dead. I mean, you can't have it both ways. Reporter: At this point, the prosecution feels it's done its job. They have proven their case against raven. But there is one more curveball team abaroa throws at them, a new possible suspect. Did anyone ask you to submit a DNA sample or fingerprints or anything for exclusionary purposes? No, no. No one's asked. Reporter: See what's next. Announcer: What do you think, innocent or guilty? And do you think brand-new evidence -- yes, there's more -- could possibly change your mind?
This transcript has been automatically generated and may not be 100% accurate.