A female mass murder.

A case study of a 44-year-old woman who committed a mass murder is presented. Following a chronic course of psychotic deterioration, and a likely diagnosis of paranoid schizophrenia that remained untreated, she returned to her workplace after 3 years from her termination and killed seven people and herself. Her history is reconstructed through investigation of primary and secondary source materials. Although there are very few female mass murderers in recorded criminal history, this case is quite similar to the known research on mass murderers in general. Such individuals often have a psychotic disorder evident in violent and paranoid delusions, show a deteriorating life course before the mass murder, intentionally plan and prepare for their assault, and methodically kill as many individuals as possible before taking their own lives. They typically do not directly threaten the target beforehand, but do leak their intent to third parties--however, in this case, leakage and other obvious warning behaviors did not occur. Such acts are impossible to predict but depend on threat management and target security for risk mitigation.