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

(Squishing an ice cream to his forehead) I'm a unitard!

Ralph

Kent Brockman: When cat burglaries start, can mass murders be far behind? This reporter isn't saying that the burglar is an inhuman monster like the Wolfman, but he very well could be. So, professor: would you say it's time for everyone to panic?
Professor: Yes I would, Kent.