A fun and easy to pull off for a group costume outing is cops and robbers, where half of you go as the fuzz, and the other half go on the run! The above costume is a great place to start: its reversible, so you can switch up your roles if you get bored. There's plenty other different styles of prisoner costume available, check out my post here for my favorites! I also have a post on police costumes for women here. If you are going as a robber, be sure to pick up a robber mask and prop money bag to go with your prisoner costume.