i think you can trust me. >> chris tapp was brought in a number of times for different interviews andi know i wasn't. >> chris gets an attorney. >> he denies any role in the crime. >> i wasn't there. i wasn't even [ bleep ] downstairs. i was nowhere around. >> police begin a series of interrogations and polygraphs that will last for nearly 60 hours. >> you're screwing with me now. >> and then he begins to change his story. >> impression i got from you is you're like downstairs waiting for him. >> maybe i was there. i don't know. >> now the police have reason to be suspicious. >> there's a saying in the law -- false in one thing, false in all. somebody who's changing his story is hiding something even bigger. >> you're in the apartment. who's with you? >> ben. >> chris tapp disclosed that he and ben hobbs were involved. >> but neither hobbs nor tapps' dna profile matched the codis profile. >> hbo hobbs' dna doesn't match, and his dna doesn't match, so they're looking for a third person. >> a mysterious third person who must have been the person who sexually violated angie dodge. >> the