If it turns out Zimmerman is not guilty Michelle can blame it all on sugar. Skittles and Arizona Tea made Tryvon go off on a sugar induced hyperactive psychotic attack.
Or, if Martin really did provoke Zimmerman by attacking him, Michelle could say, "Whitey had it comin', but he didn't need to kill the po' black boy ..." - even though Zimmerman is a Hispanic Multi-Racial ...