I think that a GPS street navigator with warnings about whenever you are nearing a high crime area would sell well.
There must be lots of apps which map crime occurences that are used by police departments.
Take a citywide crime measle sheet & scale it down to the street you’re traveling on & put that on GPS.....maybe the police already have it. Would make sense.
There were a couple. Ghetto Tracker being one.
Microsoft actually created and patented a GPS app to avoid high crime areas. They were SLAMMED over it. Do a google for gps avoid ghetto.
http://www.npr.org/2012/01/25/145337346/this-app-was-made-for-walking-but-is-it-racist