Startup Idea: Real-Time Crime Tracker Application

Startup idea to develop a real-time crime tracking app, akin to a legally permissible police scanner. The application would feature a map with crime incident icons and include a community forum/chat component. The tool could be beneficial to large cities and small towns alike.

I would like a crime tracker app in live time. As close as one could get legally to a police scanner. It should be something like google maps with crime icons, but also should include a forum/chat element. There is sooo much that can be done with this. I live in Chicago where this app would be huge, but even in small towns it would be super cool to, track the locals.