Johnny 5 0

Whereas 5 0 refers to the police generally, Johnny 5 0 is slang for a specific cop- as in, the 5 0 are on their way to arrest you, but Johnny 5 0 is the guy who actually puts you in those cuffs.

I was walking down the street minding my own business, when Johnny 5 0 popped up outta nowhere and asked me for my ID. Naturally, I got the fuck outta dodge as fast as I could.