I've been finding myself wrapped up in the story of Trayvon Martin, a 17 year old boy from Florida who was killed in a struggle with a neighborhood watchman while he was getting snacks down the street from his house, with the shooter not arrested even though he admitted to police he pulled the trigger. Here's the wikipedia page, and here's a summary by CNN of all the info gained from 911 calls and the police report.
So far as I can tell, the undisputed facts of the case are that the shooter, George Zimmerman, pursued Martin because he looked "suspicious" despite having no police authority and having witnessed nothing even approximating criminal behavior, Martin attempted to run away, Martin was an A/B student with no criminal history who was unarmed and had no drugs or stolen property on him, Zimmerman outweighs Martin by 100 pounds, and that Zimmerman shot an unarmed man in the chest.
For Zimmerman's account to make sense, Martin would have had to go out of his way to attack Zimmerman despite Martin knowing, of course, that he had no weapons, drugs or other illegal items in his possession and had done nothing illegal. He would have had to do this despite initially, per Zimmerman's 911 call, running away. Why would he turn and fight a much larger man, instead of running back to his friend's house to enjoy some Skittles and iced tea?
Much is being made of the "Stand Your Ground" law in Florida, which expands one's right to self-defense. It says that one "has the right to stand his or her ground and meet force with force, including deadly force if he or she reasonably believes it is necessary to do so to prevent death or great bodily harm to himself or herself."
Given the facts of the case as thus far presented, it seems clear that Zimmerman at least needs to be arrested. I'm all for innocent until proven guilty. But at the very least, even with the most pro-gun reading of Stand Your Ground, there are multiple reasons to doubt that Zimmerman had a reasonable belief that he was in danger from an unarmed man who was trying to run away and whom he admits chasing despite witnessing nothing illegal. This is something to be determined at a public trial.