she helped him. josh mankiewicz: for five months, bill hill says he struggled under the weight of that confession. then, in late july 2004, his conscience finally got the better of him. i decided to make my first call. your first call? to whidbey island. to the police. yes, to the island county sheriffs. i felt guilty i was giving up my friend. but i knew something had to be done. josh mankiewicz: within days of that call, detectives mark plumberg and mike beech were sitting face-to-face with both their tipster, bill hill, and their suspect, the artist formerly known as buck naked. [music playing] coming up, the interrogation gets tough. you know what you've told bill. the guy is falling apart over the guilt he's carrying around because you told him what you did. josh mankiewicz: will jim crack? or will detectives realize they have the wrong man?