Sometimes serial killers are viewed as lone wolves, not being able to connect with anyone else. The couple killers in this episode prove that sometimes killers also have companions and can form an intense bonds. For Michael (aka James Clifford / Bear) & Suzan Carson, this bond was over killing witches, hence their now famous moniker "The San Francisco Witch Killers". Australian couple David and Catherine Birnie also shared a similar cruel intentions, when they raped, bind and killed multiple women in the late 1980's - making them Australia's worst serial killers.