So, it seems like this Treyvon Martin case is kind of a big deal. On the one hand, you have a (white) man who killed a (black) kid in what is claimed to be self-defense. On the other, you have a 911 phone call in which the man is explicitly told not to follow the kid, other 911 calls in which the man is said to be chasing the kid, and apparently now also evidence that the kid was on the phone almost the whole time, rather inconsistent, one might think, with the man's claim that he was being threatened. One hesitates to bring up the racial dimension except that there's a very notable trend in this town of white people (including police) killing black people and suffering no particular consequences. Fortunately Florida and the Federal government appear to be investigating. See also useful background on the Florida self-defense law.
This is, of course, one of the downsides of localism and devolved power, and one of the great assets of a strong central government: when a town proves unable or unwilling to rid itself of its own pathologies, someone from outside needs the power and authority to step in. The envisioned societies of localists can sometimes seem to be filled with decent small-town folk, and the sorts of normal problems and shortcomings of individuals and people in groups tend to be absent. In libertarian terms: domination is just as much a problem as coercion, and in some environments, much more of one.