Impact of Age, Leakage, Military Service, and Number of Weapons on Mass Shooting Casualties

Overview: Public mass shootings occur infrequently in the United States, yet the fear of being a victim of a public mass shooting is great. This session focuses on factors that impact the lethality of public mass shootings and offers policy recommendations for reducing such violence.Proposal text: Public mass shootings, despite being an infrequent occurrence in the United States, are responsible for increasing fear among the public. Previous research has examined characteristics of offenders to begin constructing perpetrator profiles to help in the identification of subjects before a violent attack. However, research is lacking on specific factors that may impact the total number of casualties in public mass shooting events. The purpose of this study was to determine potential factors that are associated with an increased number of victims in public mass shooting events to inform future policy. A negative binominal regression analysis was utilized to determine any association between offender age, prior military training, leakage, number of firearms, and the number of casualties or injuries across 163 mass shootings in the United States. The total number of firearms and age were both found to be statistically significant factors in determining the total number of victims in a public mass shooting. Prior military tactical training was unrelated to victim count. The results of the negative binominal regression indicate that certain premeditation factors, such as the number of firearms used in an attack and leakage, and certain offender characteristics, such as age, may be meaningful correlates of the number of victims in public mass shootings.