Younger women, relative to older women, incur elevated risk of being murdered by their husbands (uxoricide). Some evolutionary theorists attribute this pattern to men’s evolved sexual proprietariness, which inclines them to use violence to control women, especially those high in reproductive value. Other theorists propose an evolved homicide module for wife killing, which means that younger women are killed more often than older women because the damage to the husband inflicted by an infidelity or defection is commensurately greater and homicide is one way to reduce the damage. An alternative to both explanations is that young women experience an elevated risk of being murdered by their husbands as an incidental by product of marriage to younger men who commit the majority of acts of violence. A sample of 13,670 cases in which a man killed the woman he was legally married to was used to test these alternative explanations. Findings show that: (1) reproductive age women incur an excess risk of being killed by their husbands; (2) relatively younger men are over-represented among uxoricide perpetrators; and (3) women married to much older men incur an excess risk of uxoricide. The current findings in principle are compatible with both evolutionary theories of wife killing. Two additional findings noted are the increase in uxoricide victimization of women age 85 and older, and older corresponding perpetrator rates in the oldest age category of 85 and older. These may represent possible “mercy killings”. Wife killing is an abhorrent crime, but not all wives are at equal risk of being killed. Identifying a risk factor associated with victims, in this case the age of the wife and the husband, represents a first step toward developing a theory of homicide with tangible practical implications for intervention. References