>> there is a phrase called garbage in/garbage out. >> garbage in/garbage out. became the strategy. if there was evidence that was contaminated or corrupted, then the results and the conclusions could not be trusted. >> for example, a key blood sample that wasn't collected from the crime scene until three weeks after the murdered. then defense dna expert, barry scheck, pounced on the lapd, accusing him and a colleague of mishandling evidence. >> there. there. how about that? >> the defense came in and just whittled in, piece by piece, little by little. >> many people who watched the trial said that the jury was bored by the lengthy dna evidence. >> put yourself there. and you are sitting there. you are listening to this stuff over and over and over.