Lou the Cop is one of Wiggum's two frequently used police officers.  Lou definitely seems to be the hardest working and most competent of the cops.

Lou Quotes

Chief Wiggum: Hold it right there, Switches of Eastwick.
Lou: Switches of Eastwick?
Chief Wiggum: I don't want to censor myself. That's how creativity dies.

Chief Wiggum: Who are you, the rules police?
Lou: No, we are the police police.

The Simpsons Quotes

Marge: Tomorrow night, it might be nice to go out for dinner.
Homer: Tomorrow night? Friday? Pork chop night? Marge! We haven't missed pork chop night since the great pig scare in '87!

Wow, now I see why they call you Miss Hoover. You must have been vacuuming for an hour.

Bart