Inmate murder is a grave threat to institutional safety in correctional settings, unfortunately relatively little prior research has studied it. The current study analyzed data from 636 capital murderers sentenced to death in California of whom 6% had murdered other inmates during their confinement career. Bivariate analyses found that inmate murderers had more extensive and violent offending histories, greater security threat group involvement, more institutional misconduct, were disproportionately white, and exhibited greater and more diverse psychopathic features relative to inmates who did not murder. Logistic regression model found that interpersonal and affective psychopathic features, security threat group, white race, and institutional misconduct history were significantly associated with prison murder. Prior murder convictions, psychopathy total score, security threat group activity, institutional misconduct, and a multiplicative term for security threat group members with psychopathy had adequate to excellent classification accuracy in a ROC-AUC model. We encourage similar data collection efforts with condemned populations to specify risk factors for individuals most likely to perpetrate murder while in prison custody.
