A mass shooting is an incident of targeted violence carried out by one or more shooters at one or more public or populated locations. Multiple victims (both injuries and fatalities) are associated with the attack, and both the victims and location(s) are chosen either at random or for their symbolic value. The event occurs within a single 24-hour period, though most attacks typically last only a few minutes. The motivation of the shooting must not correlate with gang violence or targeted militant or terroristic activity.*
*Definition developed by Jaclyn Schildkraut and H. Jaymi Elsass. The data underlying the visualizations below are collected and maintained by Jaclyn Schildkraut and H. Jaymi Elsass.