I remain baffled by those discussing the Trayvon Martin killing out of ideology trumping tragedy. There is one unassailable, absolute, 100% true aspect to this case: an armed man killed an unarmed kid. That shouldn't have happened, and should be prevented in the future if at all possible. Such an event should be found horrible by all who contemplate it.
When liberals/lefties/whatever seek explanations for social problems with a view towards mitigating them, they're routinely accused by conservatives/righties/whatever of not merely explaining, but justifying. Extending a common humanity across the board to all is oft viewed as an abdication of morality, an abandonment of holding people personally responsible for their actions, denial of a moral sense of right and wrong, and so fundamentally flawed as to perpetuate, even worsen the very problem under study. That's usually (not always) wrong: there's a fundamental difference between explanation and justification, and personal responsibility is more, rather than less, necessary in a world where easy certainties are more elusive than any of us would like.
We have here an event, as I said, that should not have happened. And we have here emerging from the right precisely the sort of reasoning that they so oft accuse the left of in caricature: a framing of the death of an unarmed kid at the hands of an armed man as not merely explainable, but justifiable.