Stereotypes of mentally ill individuals cast them as prone to violence. This stereotype has been seen throughout history and continues to persist today, especially in the news and entertainment media. The current study measured two particular symptoms of mental illness in 57 adult male participants who were incarcerated for violent offenses between September 1995 and November 1996. At the time of the study, all of the participants were residing in the Millhaven Assessment Unit for observation and mental illness treatment. The Basic Personality Inventory (BPI) was used to measure two symptoms of mental illness: persecutory ideas and depression. The criminal histories of the participants and the degree of violence toward their past victims were also measured. In terms of past violence, the authors took into consideration only mild forms of violence as mild violence tends to be related to psychiatric symptoms to a greater degree than more extreme or gratuitous forms of violence. The two hypotheses under examination were, first that as persecutory ideas and depression increased, the degree of violence and history of violent convictions would increase. Second, that the interaction between persecutory ideas and depression would make a contribution to predicting the outcome measures of degree of violence and history of violence. Results of statistical analyses revealed that as persecutory ideas and depression increased, violence toward victims decreased; the opposite of what the authors expected to find. The authors note that this result lends credibility to previous research that has failed to find a correlation between mental illness and violent behavior. Future research should focus on clarifying how mental illness and mild forms of violence interact. Appendix, references