If Zimmerman was truly the de facto neighbourhood watch captain, why not simply approach Trayvon Martin, ask him what he's doing, and only if he acts belligerent and/or confrontational allow the police -- who were already called by Zimmerman himself -- to handle the situation?

Instead, Zimmerman seems to have followed Martin down the street, refused to identify himself, and as a result Martin was wary for his own safety. The prosecution in this case has very severely bungled their attack on Zimmerman's actions and motivations, but the entire situation could have been avoided if Zimmerman was not so eager to use his gun on "these assholes" who "always get away".