Transcript for The Search for a Young Mom's Killer
Now, more of "Sleeping with the enemy." Once again, John Quinones. Reporter: Before the honeymoon is even over, raven abaroa's second wife, Vanessa, suspects he got away with murdering his first wife, Janet. He could get away with murder? I think he thinks he has. Reporter: But Vanessa says, at least for a while, raven was able to fool her and the police. He would make me believe fullheartedly that everyone else was trying to pin everything on him and that he was an innocent man. Reporter: Janet's family says they were never fooled. There was no doubt in my mind. I said, "Why did he have to kill her." He hasn't, like, set out a reward of, you know, help -- help me find my wife's killer. Reporter: Though family and friends push and plead, years pass without an arrest. This is a circumstantial case. It's hard. It's not easy. Well, you know what? Sometimes justice isn't easy. Reporter: Finally four years later, detective Charles sole gets the case. The hard part about this case, too, is for me, it's almost like you had to have like a time machine to go back. Reporter: This is unfinished business for sole. Years before, he was one of the first on the scene with a k9 police dog. Now, he's the one hounding abaroa, who is 2,000 miles away in Utah. Hey, let me call this guy and see if he wants to talk to this, you know, North Carolina detective. And I played the dumb southern cop and he ate it up. Reporter: And, watch this strange video. Abaroa records himself after one of those nosy phone calls from the cop. He wonders what the cop is really after. I feel myself getting frustrated. I'm not 100% sure why. You know, the more stuff I give them, the more stuff that gets leaked to any type of pending litigation. Reporter: In that video, abaroa also begins to wonder how he might bankroll a defense. I need to win the lottery. You know, and if I were to win $3 million, I would dedicate $2 million to fighting this. Two-thirds of my winnings, if you would. Reporter: Sole says abaroa's story just keeps changing. The lights were on, the lights were off. The child was crying, the child wasn't crying. You don't get those things wrong if you're telling the truth. Reporter: Abaroa's story is beginning to fall apart. For one thing, if Janet was killed by an intruder, sole says, he would expect to see signs of a violent struggle. Nothing was disturbed in that room. As a matter of fact, the blood was contained in a very small space. And you got to remember, just on the other wall, is her child. So, it would have been Normal for that room to be destroyed. There was no struggle. The killer came upon her and she never resisted. Why is that? Reporter: Nancy grace has also been on the case. This is what was missing. Some of his -- raven's beloved knives collection. His wife was stabbed to death and his laptop. Reporter: And she points out how lucky abaroa got with his computer, the one supposedly stolen by the killer. He backs up all of the files off of his laptop onto disks, just hours before his laptop is "Stolen" and his wife is murdered by an "Intruder." Reporter: It was almost as if he knew that computer was about to go missing. And then, there are abaroa's beloved throwing knives. Detective sole says he was very touchy on that subject. When I brought up the whole throwing knife thing, it always was like a dentist poking at a tooth that's bad. He became frustrated with me. Like, "Why do you care about this?" Well, it's kind of important, your wife was stabbed to death. Reporter: Knowing police are desperate to find the murder weapon, abaroa records another odd video, which police will later find, that's his hand, caressing the blade of a knife, he says, was overlooked by crime scene investigators. Alright, this is a knife that has been in my possession since I got my stuff back from when my brother and dad moved out of my house for me after Janet passed away. Reporter: He claims he happened to find it packed away among his possessions. It's a throwing knife. I'm going to be mailing this today, so that he can give it to detectives. Reporter: Is abaroa taunting the detectives? Could this be the murder weapon? It just kind of was bizarre that, you know, he would all of a sudden, mail a knife that would be consistent with the the wound that that she received. Reporter: Abaroa's story is, the murder happened at night after Janet went to bed, when he was off playing soccer. But police suspect Janet was killed earlier, when raven was still at home. That's why detective sole was struck by something he saw in an old crime scene photo. When you look through the crime scene photos, the first thing I'm looking at is, well, her contact lens case is open. Reporter: If Janet was wearing her contacts when she died, that suggests raven may have been lying about her going to bed before he left. Janet's family says she always took her contacts out at night. I said to myself, "Well, if she's ready to go to bed, you know, and she still has her contacts in, you know, that's unusual." Reporter: If that hunch is right, it could blow a hole in ravens's alibi, police decide to take a drastic step. The body of Janet abaroa is being exhumed tonight. Reporter: In the age of "Csi" and DNA, authorities go to work in a peaceful Pennsylvania cemetery with the bluntest investigative tool of all -- a backhoe. It was a necessary part of the process, but it was, it was horrible to see the family have to go through that. Reporter: Marking the spot at the tombstones in the family plot. Grave diggers doing their grim work in reverse. Police hoping to unearth secrets buried with the young mother murdered. Her body heading back to the autopsy table. A medical examiner has a eureka moment. When we exhumed her, yes, they were. They were present. Her contacts were present. Reporter: Proof from the grave, the most powerful evidence yet that raven is lying about how and when Janet died. It is still a circumstantial case. But police believe they have enough. Circumstantial evidence is deemed powerful than direct evidence. Yes, this is a circumstantial case. Does that change whether he's guilty? No, it does not. Reporter: Abaroa is arrested, extradited back to North Carolina and put on trial for the murder of his
This transcript has been automatically generated and may not be 100% accurate.