Superhomicide offenders: Nosology, empirical features, and linkages to sexual and multiple murder typologies

The nosology for criminals who murder multiple victims is at once well-established and controversial, perhaps because theorists have largely segregated such offenders from the broader criminal population. The current study introduces the superhomicide offender, an individual convicted of at least five murders, to locate multiple homicide offenders within the criminological and epidemiological science pertaining to the most pathological offenders, and statistically place them with other conceptualizations of severe offenders at the 95th percentile of the offending distribution. Relative to other capital murderers, superhomicide offenders have lengthier criminal history, greater conviction history, and coextensive psychopathology characterized by psychopathy, sexual sadism, homicidal ideation, cluster A and B personality disorders, and major depressive disorder. Superhomicide offenders are profoundly psychopathic with 20 of the 39 offenders reaching the clinical threshold of 30 or more on the PCL-R, and 19 of the 39 are sexually sadistic. Regarding extant typologies of sexual and multiple homicide offenders, 15 are serial murderers, 17 are sexual homicide offenders, 17 are mass murderers, and 17 are spree murderers. Twenty-four of the 39 superhomicide offenders (61.5%) met criteria for multiple typologies, suggesting the new prototype can help unify the study of those who perpetrate multicide and embed them within criminological and epidemiological models that specify pathological antisocial outcomes.