This is off topic, but a question I don’t hear people ask in regard to the Zimmerman case is: why didn’t any of the several people hearing screams intervene to stop the brawl? Never mind who was screaming, no one felt an obligation to intervene. Eye-witness John Good came out and said something like “stop” but then immediately ran back inside. Others could be heard saying, “don’t go out there”. I don’t say they should have joined the fight, but if a few people had gone outside and screamed or blew a whistle it probably would have been effective.
(I’ve been in such situations twice.)