Although research has independently examined the characteristics of mass school shootings and school firearms violence, few studies compare mass to non-mass school shootings. We quantitatively examined how social (e.g. peer bullying), behavioral (e.g. behavioral health), contextual (neighborhood disadvantage), and situational (e.g. acting alone, firearm type and access) factors associated with school firearms violence differed between mass and non-mass incidents. Using data from TASSS (n = 389), we analyzed two measures of mass shootings: incident outcomes and violent intent. Findings show mass shootings are rare. Only 10% caused four or more total bullet wound injuries, while 16% displayed indicators of mass-violence intent. Behavioral health issues, lower neighborhood disadvantage, and high-powered firearms increased the likelihood of mass shootings, while peer bullying had limited influence. These findings have policy and theoretical implications, as behavioral health was linked to casualties and premeditated intent, and less disadvantaged communities may face distinct pathways to large-scale violence.
(Publisher abstract provided.)