I think the question surrounding the Zimmerman case is this:
1. GZ sees many robberies in his neighborhood committed by young, black male criminals.
2. GZ is on the lookout for young, black males whom he finds suspicious.
Does this make him racist?
Many white people do not encounter many black people in their day to day lives.
What they know of black people, especially young, black males, is what they see on the news.
What they see on the news is young, black males committing crimes.
If these white people are wary of young, black males, does this make them racist?