This research addresses recent calls to incorporate multidisciplinary approaches in the study of firearm violence by utilizing an elaborated criminal events perspective to explore the correlates of firearm injury severity. A unique dataset of nonfatal firearm injury data are derived from official police reports, allowing the use of a medically validated measure of injury trauma in place of more typical injury indicators. The relative and collaborative contributions of criminological and public health indicators for explaining variation in levels of injury severity are assessed. Multinomial logit models suggest that critical injuries are more likely among older victims, victims who knew their assailants, and victims who refused to cooperate with police. Additionally, the likelihood of critical victim injuries decreased as the time to report an incident to the police increased. The strongest correlates were measures of incident circumstances and the number of gunshot wounds a victim received. In all, these results reveal that a combination of measures from both fields is needed to provide a deeper understanding of injury severity outcomes.