I think you're missing a larger issue here in that you, and by-and-large the Ferguson protestors, claim that the amount of force used by the police officer was excessive on the sole virtue that Michael Brown wasn't carrying a weapon. But if the accounts of Michael Brown assaulting the officer, and severely damaging his face, are true--and it is looking that way--then that calls into question your, and their, standards of "excessive." If his life was in jeopardy, it wouldn't matter what his intent was when he fired at him.