I guess that we did not have the same experience in our neck of the woods. All seemed calm at Armstrong.
I just don't find that every group of kids walking on the block is looking for trouble. Walking while African American is not a crime to the best of my knowledge, nor is possession of dark skin with intent to stroll.
FWIW, just say hello or introduce yourself every once in a while, 'when appropriate,' but report questionable activity. You might actually make friends with a good neighbor, rather than elevate the anxiety and tension.