Guided by evolutionary psychology and a situational perspective on violence, we generated three hypotheses to investigate whether the percentage of intimate partner homicides by beating, a hands-on homicide method, varies with the victim-offender relationship. We tested these hypotheses with a national database that includes incident-level information on over 50,000 intimate partner homicides. The results indicate that (1) men are more likely than women to kill a partner by beating, and (2) men are more likely to kill their partners by beating when the relationship is dating or non-marital cohabiting (versus legal marriage). We argue that the lack of commitment in these non-marital relationships may produce greater jealousy in men, driving the perpetrator to kill his victim in a more violent manner (i.e., beating), relative to men who kill their wives.