Most of the literature on intimate partner homicide addresses violence between the two partners, spousal abuse, and family violence. There is less focus on the relationship of mental illness, intellectual functioning, and drug and alcohol abuse to these homicides. We investigated this type of homicide in a collection of forensic cases seen by the first author over a period of 10 years. Twenty-eight patients who underwent forensic psychiatric evaluation for heterosexual intimate partner homicide from August 1993 to June 2003 were studied using a retrospective case review methodology. We found that firearms were used as the method of killing more often by females than by males. We also compared method of killing with substance abuse and intoxication at the time of the homicide. Educational status indicates that this group of accused perpetrators is functioning at higher intellectual levels compared with a previously studied sample of filicides. We also found significant presence of serious mental illness in our sample of accused perpetrators of heterosexual intimate partner homicide.