alvin. >> i was very annoyed, actually, because it was obvious to me as a professional that alvin was incredibly slow. and that he was being taken advantage of. >> dr. richard leo, a professor of criminology and psychology at the university of california at irvine, agrees. >> this is an awful, awful interrogation. i think this is shoddy, poor police work, and i think these -- the detectives who conducted this interrogation should be retrained. and until they're retrained should not be permitted to do another interrogation. >> during the first day of police interrogation, alvin denied he killed tinky. >> never. >> come on, alvin. what are you going to do? say something. explain it. >> what you saw was an incredible amount of intimidation. over 100 times, alvin said that he did not do it. he was emphatic in saying that he did not do it. >> why did you stab him? >> i didn't. >> why did you stab him? >> i didn't.