The homicides all involved victims and perpetrators who were related directly or indirectly through blood or an intimate relationship. Results revealed that 18 percent of the perpetrators committed suicide. Suicide occurred only after the killing of an intimate partner, an offspring, or both. Results were also consistent with an evolutionary perspective in that homicides followed by suicide were most often attributable to male proprietariness or mental illness. Male proprietariness was demonstrated by the killing of former intimate partners or offspring following an intimate separation. In contrast, none of the murders that occurred as a result of child abuse, family conflict, financial or criminal motives, or violence by the victim was followed by suicide. Tables and 11 references (Author abstract modified)