Police don't skulk around in the shadows at night, waiting to observe crimes. Crimes occur far too infrequently for that strategy to make any sense at all.
They're either in cars or if they're patrolling on foot (which is basically only something that happens in very dense commercial areas), they're dressed to be obvious and noticable. That's the mechanism by which police can prevent/displace crime: would-be perpetrators see police and choose to wait, commit their crime elsewhere, or (potentially) cool off and not commit the crime.
They're either in cars or if they're patrolling on foot (which is basically only something that happens in very dense commercial areas), they're dressed to be obvious and noticable. That's the mechanism by which police can prevent/displace crime: would-be perpetrators see police and choose to wait, commit their crime elsewhere, or (potentially) cool off and not commit the crime.