Mac is a Serial Killer

Mac's strange and mysterious behavior just happens to coincide with a string of recent murders. Frank concludes that Mac must be the serial killer and wants to torture a confession out of him, preferably with a chainsaw. Charlie uses his knowledge from <i>Law & Order</i> to protect Mac and tries to convince Frank that Mac is not the killer. Dennis and Dee try to find the real culprit by thinking and acting like serial killers.