I know you will not listen but I will tell you anyway how the Neighborhood watch works. My neighbors and I, implemented the same in our neighborhood nearly 20 years ago now. We did so because we have no police patrols and any protection we have will be provided by us.
People work together to keep track of traffic and people in and out of the neighborhood. One key aspect is that we know everyone that lives here, who is here, and who is out for awhile. When new people move in, they are introduced to the Neighborhood watch. All realtors know to do this and most people that do watch check out the new people.
Trayvon moves into the neighborhood and he is not introduced to the watch or the neighborhood. So he is unknown. He would likely survive the discovery if he had known not to go whoop ass on the neighborhood watch. Perhaps he did take offense at being watched, perhaps black people are offended by the concept. Perhaps the size of the watchman emboldened him, a fatal mistake. It was not a good idea to go whoop ass.
Yes, we have a neighborhood watch, even though there are hardly any black people in the county. The watch works the same though.