Tap the brakes, FRiend. There is no evidence that he was a "thug" and it is indisputable that he was well within his rights to be in the neighborhood. He was residing as a guest of a resident (his father and father's fiancé.)
It is entirely reasonable, and consistent with all known facts, to believe that Zimmerman acted in self-defense, even though Martin was a basically good kid, who certainly does not deserve to be dead. But he is dead, as a result of a tragic chain of events involving poor judgment by both parties.
Friends of both parties say they were friendly, decent, good people. That's the tragedy here.
I don't think either one displayed poor judgement. If the claim by the girlfriend of Trayvon Martin is true, that the two of them had the following exchange, and to paraphrase:
Why are you following me...why are you hereThen their actions and behavior up to that point are perfectly reasonable and rational. Whatever happened, happened after this point. That's if what the girlfriend said is true. I have no idea either way because it hasn't been documented to my knowledge.
My personal belief, so far, is that a disputed, but not necessarily contentious, social situation triggered something personal in one of them, and it happened quickly.