Episode 412, "Knuckle Up" Friday, May 24, 12|11c
SEASON 2, EPISODE 221 - The unsolved 1977 case involving the death of Philadelphia doorman Mike Cahill (Zack Graham) is reopened when Rush and Valens try to link his murder to a serial killer about to be released from prison due to a legal technicality. The detectives uncover the unusual relationship between Mike and the serial killer, Roy Anthony (Barry Bostwick as present-day character - ""Spin City,"" ""The Rocky Horror Picture Show""). Mike worked at an upscale apartment building and was oddly close with one of the married residents, and Roy was a severely troubled teen with an abusive father. Eventually, Rush and Valens discover that Mike's girlfriend at the time of the murder also worked with Roy at a local diner and that a midnight screening of the film ""The Rocky Horror Picture Show"" was the event that brought the trio together.