Agent Malloy says in her introduction that she called Charlie in because she knew he "worked on the recruitment center bombings, and before that the backdraft arson investigation;" these cases are the focal points of episodes 2x16 "Protest" and 2x11 "Scorched" respectively. She also says that Nikki Davis was a friend of hers, referring to the ATF agent and Don's former fiancee who was killed in episode 2x20 "Guns and Roses."
(Jason Aronow) Kyle Howard and (Larry Fleinhardt) Peter MacNicol both starred in the film Baby Geniuses (1999)