Naked City (1958)

S4E34 Barefoot on a Bed of Coals

After a man is unsuccessful in his attempt to join the NYPD, he decides to impersonate a uniformed officer. His reasons stem from a desire to help the community and to impress attractive women. However, when he gets caught up in thwarting a robbery and brandishes a non-standard firearm, the genuine NYPD begins to hunt him down.