documents show a police officer called the shooting, quote, avoidable had zimmerman remained in his vehicle and awaited the arrival of law enforcement. in a review of the cause, it was determined that george zimmerman yelled help or help me 14 times during approximately 38 seconds. trayvon's own father confirmed the voice on the recordings was not his son's, contradicting statements he would later make. t.j. winick, abc news, new york. >> a lot of new evidence coming out on this. obviously, 200 pieces. one investigator, to reiterate, said the whole thing could have been avoided if zimmerman had simply stayed in his car and waited for police to get there instead of taking matters into his own hands. again, the key question here is that -- still not clear who provoked what? >> what happened? >> that's the thing. >> as we've been saying, that is the black hole in the investigation. how did they end up where they were on the floor during this altercation? that's what everybody wants to know. why did he pull the trigger?