A recent Reuters profile of George Zimmerman explains the context in which he shot Trayvon Martin on February 21. It does not provide direct evidence one way or the other on the question of whether Zimmerman's use of force was justified, but it does complicate the widespread perception of him as a racist hothead and overeager wannabe cop.
Aside from the fact that he deemed a black teenager "real suspicious" (based partly on behavior that struck him as odd), there's little evidence that Zimmerman is racist. Reuters notes that he has "an Afro-Peruvian great-grandfather," was raised in a multiracial household, and has black friends, including his partner in a short-lived insurance agency. Another relevant (and ironic) part of Zimmerman's history not mentioned by Reuters: Last year, according to his family, he distributed fliers at black churches protesting the lenient treatment of a white police lieutenant's son who was caught on video assaulting a black homeless man.
"I'm black, OK?" a neighbor tells Reuters. "There were black boys robbing houses in this neighborhood," she said. "That's why George was suspicious of Trayvon Martin." The details about the rash of burglaries and home invasions help explain Zimmerman's multiple calls to the police and his anger at the prospect that yet another suspect was about to escape on the night he shot Martin. His frustration may have prompted him to continue following the teenager after the police dispatcher suggested he stop (although that point is a matter of dispute).
The profile notes some previously aired evidence that Zimmerman was prone to violence: his 2005 arrest for shoving an alcohol control agent who was arresting his friend for underage drinking and a restraining order against him by a former fiancee. It also confirms that, contrary to neighborhood watch guidelines, he made a habit of carrying his gun (which he originally bought as protection against an aggressive neighborhood dog) while patrolling the neighborhood. Although those facts reinforce the impression that Zimmerman was looking for trouble, the main thrust of the piece is that he was a good neighbor genuinely interested in helping others and working with the police to address a crime problem that had everyone on edge. That motivation got him into a situation where he made a tragic mistake—one that, depending on the details of his fight with Martin, may amount to a crime.
[Thanks to Manny Klausner for the link.]