This is a very good way to clean up all precincts quickly, without getting a Bad Cop rating. Get in a car and ram into another car that someone is driving. The driver will get out of their car angry and start provoking you while throwing a big fit. Get out of your car while they are still throwing a fit and wait until you see a health bar over their head. You can now beat them down and arrest them for a quick and easy three Good Cop and three Career points. You can repeat this until you clean up the area.