See the thing I keep coming back to is that none of this background stuff is relevant. Really the Sanford Police started it when they said in their reasons for not charging Zimmerman that: "he has a clean record" and "we respect his background". At the same time it is not relevant if Zimmerman had been arrested before or even charged or convicted.
Neither of which is relevant to whether the shooting was murder/manslaughter or self-defence. For the same reasons Martin's background is not relevant to whether it was murder/manslaughter or self-defence.
As Kit Walker said in the Worst Comics thread - "What is relevant is what they were doing that night".
I also agree that this should not be tried in the Media and as much information should be obtained without jumping to conclusions. However it seems to me that without the media this was a case that was NEVER going to be tried at all. And it should be. That's what people should be upset about that this wasn't even going to get to a jury until people started complaining about it in the media.
The backgrounds are marginally important if only because there are no reliable witnesses of the actual event. Thus we have to use available evidence based on personality and background to figure out the most likely scenario. The fact that Zimmerman seems to have a history of causing trouble lends precedence to the notion that he started the confrontation. However, similar background checks need to be made about Martin because it could imply that he started that confrontation and thus Zimmerman was "justified" in his self-defense.
However, you are right in one thing though, I doubt anything would have happened if the media did not step up and cause a stink. I doubt this would have seen justice and to make it worse those within the police department that were happy to just ignore this case would still be free and unchallenged to ignore other cases. Even if Zimmerman is found to be innocent of murder gets off free on self-defense, the fact that the federal government is looking into the conduct of the police department is a good thing.
Unfortunately the media is becoming clogged with lies, opini9ons and falsities. An example is how fox news went on a pro9longed rant about how Martin could have been suspended for everything from theft to fighting. The different media sources are picking sides and that is a problem, they are negatively affecting public opinion and may affect the juries decision when this does go to court.