cathy. where the heck could she be. reporter: he had always been cooperative. he voluntary gave head ir samples, he gave a blood sample, he gave finger prints. and at the end of that, he ultimately said, you know, whatever i can do, i ll do. reporter: but as he read the file, daron learned there were other things sam didn t do. for example, sam lived right down the street, yet cathy s family says he never stopped by. during that whole frantic week when they were searching. he did speak extensively with police. i don t think anybody thought that sam was telling the truth. reporter: remember how sam told detectives cathy came to him looking for weed? the first thing she said is, uh, could you get me any weed? reporter: but there was absolutely no indication that any of that was true. which calls into question sam s story. it does. coming up as daron digs deeper into the case.