When a guy is 20, his other brain may steer him into trouble, but at his age, common sense should have kicked in for no other reason that self-preservation. He may not be the racist murderer the media tried to paint, but he is indeed, an imbecile.
Some additional here on his bail and release...
http://www.wftv.com/news/news/local/george-zimmerman-arrested-aggravated-assault-charg/njkbn/