William and Steven are both anger-excitation rapists incapable of empathy, deriving pleasure from the pain they inflicted on their victims. Unlike most killing teams, which have a dominant and submissive, William and Steven were both dominant personalities and alpha males, which, while rare when it comes to killing duos, is not completely unheard of. Essentially saints in their personal lives, it was the presence of a dark side and feelings of emptiness that drew the two together and made them feel complete. The longer Steven and William get away with their crimes, the stronger their relationship grows, with the two becoming more addicted to rape, torture, murder and each other. Had they not met, the two likely would have continued committing sexual assaults, but may not have escalated to murder.
Harris and Baleman appear to have been loosely based off of killing team Angelo Buono and Kenneth Bianchi, The Hillside Stranglers. Just like Harris and Baleman, both members shared the same predatory personalities, were psychopathic sexual sadists, had a fight that eventually led to their incarcerations, and raped and tortured their victims before strangling them (although Buono and Bianchi used ligatures while Harris and Baleman used manual strangulation).
Harris and Baleman are also similar to Lawrence Bittaker and Roy Norris, a.k.a. "The Toolbox Killers. Both killing teams had members who were ephebophilic serial killers, rapists, and sexual sadists who targeted women, abducting, raping, and killing them by strangling them. Both also committed crimes prior to killing together. In addition, in both cases, it was initially assumed that only one person was committing the murders.
- November-December 2008:
- Kim Groves (raped by both; killed by William)
- Two unnamed victims (raped by both consecutively; killers unspecified)
- January 10-11, 2009: Missy DeWald (bitten and killed by Baleman; possibly raped by both)