According to Kelly Lynch, she and Denzel Washington were supposed to kiss. However, Washington had the scene dropped because he felt an interracial love scene would hurt the film's box-office chances.
The Raumschiff Enterprise (1966) episode shown briefly is The Enemy Within (1966), an episode about Captain Kirk being split into good and evil sides by the transporter.
Amongst the names of serial killers shown in Sid 6.7's personality profile are David Koresh, Thomas McIlvane, Frederick Cowan, William Bonin, Harvey Glatman, Peter Kuten, William Bryan Cruse, Charles Whitmore, Aileen Carol Wournos, Peter Sutcliffe, Kenneth McDuff, Jesse James, Dr. Glennon Engleman, Harvey Carignan, Dr. Geza de Kaplany, Norman Selby, Juan Peron, Winnie Ruth Judd, Matthew Grimes, Augosto Pinoche, Carl Panzram, Abu Nidal, Ted Bundy, Wesley Allan Dodd, Roger Dale Stafford, Elizabeth Borden, Mark Essex, Billy the Kid, Lynette Fromme, Larry Eyler, Clem Henderson, David Hendricks, Coral Eugene Watts, William McDonald, Richard Trenton Chase, Sirhan Sirhan, Josef Mengele, Ed Kemper, Edward Leonski, John Collins, Julian Knight, John Haigh, Carlton Gary, Vaughn Greenwood, Nicolae Ceausescu, Randy Kraft, Miguel Rivera, Dean Allen Corli, William Suff, Werner Boost, Thierry Paulin, Richard Trenton Chase, David Burke, Donald Harvey, Vernon Butts, Bruno Hauptman, Ralph Jerome Selz, John Duffy, Carl Weiss, Gerald Eugene Stano, Benito Mussolini, Paul Calden, Richard Farley, Ian Brady, Joseph Harris, Hiro Hito, Lynwood C. Drake, Saddam Hussein, Gilles De Rais, Herman Mudgett, Donald Nielson, Robert R. Diaz, and Joe Ball.
Action editor Billy Weber was brought in by Paramount to deliver a new cut of the film, after the initial cut was rejected. For his efforts, he is thanked in the film's closing credits.