Aggravated Assault Achievement
Stop all assaults in Arkham City
Ever vigilant, stop all 16 random crimes in Arkham City (Arkham Assault). A crime is taking place when you are picking up hostile chatter in the Local Surveillance feed. Use detective mode to track who is talking, then knock out the henchman to free the Political Prisoner. The map will sometimes display a pulsing hexagon in the location of a crime even when you're not close enough to hear the chatter, so check your map often.