CNN Anderson Cooper 360 June 25, 2013 05:41:00
Self defense to save his own life. now, the defense played a 911 call from a neighbor in which you can hear screams in the background. audio experts that analyzed the call say the screams are not coming from zimmerman, but the judge, deborah nelson ruled the experts cannot testify. she says there's no evidence their techniques are generally accepted. there's no real validity to them. going to speak with one of those so-called experts in a moment, you're going to hear from him, you can determine for yourself how you feel about it. here is some of the neighbor's 911 call, trayvon martin's mother...