Results: Fifty-eight percent of the sample had at least one axis I or II diagnosis, most often a substance use disorder (47%). Axis I or II diagnoses were more common (78%)among defendants over age 40. Although 37% of the sample had prior psychiatric treatment, only 8% of the defendants with diagnosed axis I disorders had outpatient treatment during the 3 months preceding the homicide; African Americans were less likely than non-African Americans to be in treatment. African American males were more likely to use a firearm and to have a male victim. In exploratory analyses, psychiatric factors did not predict multiple victims, firearm use in the crime, or a guilty verdict.