We continue with I know what you did. Once again, david muir. Reporter: Almost four years to the day after levi karlsen was crushed to death under a truck, that insurance policy taken out just 17 days... See More
We continue with I know what you did. Once again, david muir. Reporter: Almost four years to the day after levi karlsen was crushed to death under a truck, that insurance policy taken out just 17 days before, and his father, the executor -- karl karlsen now sitting inside this interrogation room. Across from investigators. What killed him? The truck. How'd the truck kill him? It landed on him. And I had nothing to do with the truck landing on him. Nothing. Absolutely nothing. Reporter: So you haul him in and begin asking questions. How many different stories did he have? Three. Reporter: Version one? Karlsen says he and his wife come home from a funeral and a dinner afterward to find levi dead under the truck. But soon version two. He was now saying that he and his wife were preparing to leave for that funeral when he discovered his son in the garage, pinned under the truck. The truck had already been fallen over. And I found him dead. So this was around noon, you found, around noon or just before noon you found him? You went out there and the truck was rolled over on him? And I panicked. I don't know. I don't know. So you panicked in what regard? Just --i left him. Now you saw him did you run over and call medical help, call 911, did you get help? No, I didn't do anything. I froze. Now was there a phone in the garage? Or a cell phone or did you run back to the house and call 911? No,i went to the funeral. Reporter: So he saw his son dead and trapped under the truck and still left for the funeral? Yes. Reporter: He says that father didn't return until four hours later. During the interrogation, karl karlsen asks repeatedly for his pain medication during the interview, medication he says might have altered his behavior the day levi died. Like I say if it was due to medicine, I don't know, I won't play that card or whatever. And then, several hours into the interrogation, karl karlsen appears to be on the verge of yet a third version of his story. I could never hurt him, i couldn't. You're that close. Man, you're close. Come on. Let it out, let it out. Let it out. Couldn't do it. I'll walk with you. Was it just a split second thing? I couldn't hurt him. I opened the truck door. Okay. And when I did it -- truck. We've gone from he was dead when you walked in there, to it fell when you opened the door. I know. So take the final step. There is no more. I stepped in the truck and the thing fell. And I was just scared , I don't know why. Reporter: His son trapped by the truck and yet they still leave the house? Yes. Reporter: Does that make any sense? No. I can't imagine walking away and leaving your child dying on the floor. Reporter: They were going to a funeral. Yes. Reporter: And yet many would argue he had just created one right here in his own garage. It's fair to say that. Reporter: Karl karlsen continues to insist he's innocent, opening up to the "syracuse post standard" about his son from inside the county jail where that father is sitting tonight. Well, levi, I mean when he was younger, we had problems with him, um, um, school was hard for him. Um, losing his first mother was really traumatic, would be for anybody. Reporter: He talks about levi as a young father, that he took his son back in after levi's divorce. My wife and I took him back in and he -- I decided to stick my neck out for him and told him what his responsibilities would be. He became responsible, he had manners, he grew up. And he realized that mom and dad weren't out to make his life miserable. He got life back into him. Reporter: As that father now awaits trial in the coming ys -- his daughter, levi's sister erin and her aunt, collette say they're relieved their long-held suspicions will now play out in court. They're hopeful investigators in california will charge karl karlsen in the death of his first wife, too. I believe karl killed my sister. And because calaveras county didn't do their job, they enabled him to kill again. And he killed my nephew. And it's all linked to money. Reporter: Jurors will not hear about the death of his first wife. The judge ruling it's off limits. Prosecutors must stick to what happened to levi. His sister erin wants answers for both loved ones. I want to hear it from him. I want to hear those words come out of his mouth. I want him to look in my eye and tell me exactly what he did. And then I want him to go away for the rest of forever.
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