I am going to return to the Martin case. Perception is often determined by visual clues.
Most jobs have uniforms and dress standards. The reason that this is the case is that the public expects a certain decorum and or professionalism. Woulld you really want to invest your money with a banker dressed like a pirate or a vampire? They could be excellent at their job, but most people really don't want to think of their financial professional as a pirate. Similarly, teachers do not get to dress up like circus clowns as doing so would distract from the lesson. Federal officers do not get to dress up like Ninjas.
Martin dressed up in a particular attire that is well known to big city residents and anyone familiar with popular culture. While it is true tatoos and the gold teeth are unlikely to be seen at night. The hoodies and the baggy pants and silly walks present an image. When we dress like criminals people are going to react to the visual clues. Thus you have a nervous night watchman and a person dressed like a stereotype gang member. This was not the case of a forever lost Steve Urkel in suspenders and flood pants making a wrong turn. You have a person dressed up like a criminal in a gated community. A better watchman engages the person verbally and feels them out. This gives a professional notice to criminals as well and most ply their trades elsewhere.
From many accounts in the press the girlfriend reported Martin said "Why are you following me". At this point Zimmerman is likely on solid ground. Where he likely fumbles is the next point. Some reports have a nasty verbal exchage when Zimmerman tried to call for help. A professional response likely gets Martin to move on or ascertains where he is going. Failing that it establishes that the odd behaviors are being observed.
We do know about Zimmermans past anger issues and incedents. We also need to take into account Martin was the genuine article. The gangster tweets and suspensions, drug use are on solid ground. The petty thefts at school are less solidly reported but likely accurate. It apears that Martin attacked Zimmerman, who was smaller and frightened. The injuries and stains are consistent with his account of events.
At this point it is likely that investigators need to do their job. Zimmerman might be charged with some form of manslaughter and the worst case scenerio was a bumbling wannabe cop messed up and got his butt kicked and responded with lethal force inappropriately. This is clearly not a cold blooded killing and despite the hysteria may be charged at a low level.
The reactions of the left at Harry's place where a SF socialist talks of the South as if Bull Conner were still the norm. These types of racial incedents are far more likely to occur in the liberal enclaves like NYC or Oakland than Atlanta. Native born Blacks and many Puerto Ricans have been leaving urban areas for the South for decades. The Blacks one encounters in a big city are frequently Africans or West Indians. There is plenty of tension between these groups of Blacks. It is not uncommon to hear Africans from Ghana complain about street culture.
Times have changed.