actually it wasn't. what the son said was that, yeah, they'd gotten a video and the son was watching it. he doesn't know where dad was. >> dad wasn't sitting beside him in the room? >> no. dad was not watching with him, so he doesn't know where dad was. the son got bored watching this movie, and i believe he went and got on his computer. so there's a period of time that we don't really know. he might have been in the house, but nobody saw him. >> reporter: so maybe knapp's solid alibi wasn't? and remember how he told everyone he had cancer? sharon, a doctor, discovered something about that. >> i've seen the medical records. >> and? >> he had a superficial type of skin cancer at one point, and it had been removed. so no, he didn't. >> reporter: steve's family even recorded this video, after the murder, in which jim knapp said things about carol they found deeply disturbing. >> because carol and i lived a