The subjects were randomly selected from a pool of the inmate populations of 8 minimum to maximum Federal correctional institutions in Canada. The Psychopathy Checklist (PCL: Hare, 1980) was used to assess psychopathy for each inmate in the pool. PCL, a reliable and valid instrument for assessing psychopathy in prison populations, contains 22 items reflecting personality traits and antisocial behaviors. Police reports were obtained which described the offenses responsible for the current incarceration of 55 psychopaths (Group P) and 46 nonpsychopaths (Group NP). A detailed analysis was performed on the most serious of these offenses (the target offense). The results were consistent with prediction. Most of the murders by Group NP, but none of those by Group P, occurred during a domestic dispute or during a period of extreme arousal. There was no difference between groups in the degree of harm inflicted on victims who were not murdered. Most of the NP's victims were female and were known to them, whereas the opposite was true of Group P. Tabular data and 17 references. (Author abstract modified)