Impersonating a law enforcement officer is a good way to get killed or arrested real quick. It’s also a good way to get attention from people who are easily impressed. Especially when you walk in openly brandishing your gun, badge, flashlight and telling everyone within earshot that you are a U.S. Marshal, along with walking out without paying the $3 for the beer you drank. Also, the employees know who you are because you used to go out with a former employee.
That’s not a Fed haircut.