Watch It's Always Sunny in Philadelphia: Mac is a Serial Killer Episode 310 Online

It's Always Sunny in Philadelphia: Mac is a Serial Killer Episode 310, Summary: Mac's unusual behavior leads Frank, Dennis and Dee to suspect that he's the serial killer on the loose in Philly. They devise a plan to catch Mac in the act, while Charlie utilizes the vast legal knowledge he's learned from TV shows to prove Mac's innocence.

This series will be aired on Monday on 28 February 2011 at 10:00 PM on Comedy Central.