Find out where the high crime centers are. It may surprising at the number of neighborhoods that are "high target, high activity" areas. It is not just in the areas that you would consider obvious.

Check the school system reports for violence and the level of parent/teacher organization activity; unless you are homeschooling.

Get a map of the public transportation lines. It is nice to be close if you are a one-vehicle family. Actually, it is good either way.

My $.02