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

It's Always Sunny in Philadelphia: Mac is a Serial Killer (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 05 July 2010 at 10:30 PM. If you want to see the full episode please visit TV Mixer.