leah hubbard and michael roehrig needed to prove it was really murder. >> of course, there's only onehat night, and that's daniel clay. and he's certainly no friend to the truth. >> although lead prosecutor roehrig admitted some of daniel's story was plausible. >> i think that the fact that she was alone at the party without a phone, without a ride home, it was cold, and she was dressed only in that costume, i think, does play a role here because i think it makes it somewhat more likely that she might have accepted a ride from the defendant whom she would probably have been acquainted. >> but what happened after that, the state argued, chelsea did not agree to. >> it seems fairly likely that daniel clay demanded of chelsea that -- something that she didn't want to provide to him, and he obviously used massive force against her to get what he wanted and ultimately killed her in the process. >> daniel clay's claim that chelsea asked him to choke her and after 20 or 30 seconds she expired? on the stand, here's what the medical examiner said about that. >> there was nothing left for me to