<p>In the United States, there is a moral panic about mass murder – a phenomenon representing a very small percentage of all homicides – committed by strangers in public spaces (e.g., school shootings, concert killings, church slayings, movie theater massacres, etc.). While such devastating events do occur and can be fear-inducing, the bulk of mass murders involve male offenders killing women they know. Less attention, however, has been given to these victims, which creates a problematic social milieu that devalues their lives and lived experiences. As such, this study investigates mass murder in America through a critical criminological lens. More specifically, it explores male mass murderers’ histories of gender-based violence (e.g., intimate partner violence, sexual assault, stalking, etc.) using data from the Gun Violence Archive as well as open-source information (e.g., news media reports and public information). The findings reveal that a substantial portion of offenders, approximately 80%, have histories of violence against women and girls, making it one of the most common risk factors among mass murder perpetrators. The study also reveals that these highly gendered crimes mostly took place in death penalty states (73.2%). The implications for reducing and preventing violence are discussed, along with directions for future research.</p>