mike preadmore: right away, soon as we had it. get flooded with phone calls. we didn't realize how common of a look that actually is. i mean, a lot of people actually look like the sketch. keith morrison: mike williams offered an opinion. it looks like 150 different people that i know. you know, i don't know-- i can take you to a bar right now where everybody in the bar looks like that. keith morrison: but mike told the detectives that a couple of members of a milwaukee band that worked the party looked a bit like the sketch. maybe talk to them, i don't know. maybe she hopped in their tour van and went back to milwaukee. i don't know, she was kind of a free spirit. so i mean, i thought maybe she just cut town, you know? so we sought assistance from the fbi tracking them down, nothing panned out. they all had alibi? yes. keith morrison: but big mike-- neither the detectives nor chelsea's family could shake the idea this guy was hiding something. coming up-- brian sroka: we asked for his consent to search the house, and he denied us

keith morrison: and then detective preadmore told daniel a lie.ase. brittle bone bone disease. brittle bone disease is a i had to do something to relax daniel clay and open him up to talk to me and tell me what happened. so this is where the brittle bone disease came in. and at that time, i think, in the interview is where the turning point daniel clay kind of leaned back and was like, oh, yeah. yeah, that brittle bone-- i've heard of that. that's-- i had my hand broke one time real-- and he goes on. keith morrison: the detective could almost see the wheels turning in daniel's head. if her bones broke easily, could he say her death wasn't his fault? daniel, not so calm anymore, asked for a cigarette and told a new story, that he saw chelsea walking down the road after the party and offered her a ride. and then, he said, they had sex in his car again, and this time, things got freaky. got underneath me and. >> like. >> i don't know, we were for a minute and then she kind of stopped and she went limp. so i stopped and i'm like, you know. and i start