“Over the past eight years, he called the Police Department at least 46 times with reports of various sightings.”
http://www.freerepublic.com/focus/f-news/2863232/posts
Sounds like a neighborhood where shootings aren’t uncommon.
Kids playing in the street
Garage doors open
Loud music from a car
A guy in a tank top and khaki shorts carrying a (gasp!) paper bag.
http://www.sanfordfl.gov/investigation/docs/911CallHistory.pdf
I haven't seen anything to suggest that "shootings aren't uncommon" in the neighborhood. The fact that Zimmerman called the Police Department doesn't indicate that there are a lot of shootings, or any shootings, in the neighborhoood.