The US Department of Justice recently released an 18-page summary of active shooter statistics for every attack that met the FBI definition between the years 2000 and 2018, and Greg Ellifritz provides highlights, which I edit down further:
The majority of casualties occurred in “Open Areas.” Cops use large buildings like schools, churches, and vacant offices in which to conduct their training. Very few cops get training on how to cross open ground under fire to approach an outdoor active killer site. That needs to change.
The average active killer event results in two people injured for every one person killed. This has been true for as long as people have been keeping statistics about the topic. The statistics remain the same for this subset of killings. Lots of cops embrace the role of being the guy who hunts down and slays the killer. Fewer cops embrace a role where they are helping the injured.
Out of 277 total incidents, only four involved multiple suspects. Most events were perpetrated by a single killer who was arrested on scene by responding cops. Police agencies who amass large groups of officers before entering are wasting time. The chance of needing 360 degree coverage for multiple threats is almost non-existent.
Most active killers used handguns. Although many of the killings with a high body count were perpetrated with semi-auto rifles, 2/3 of attackers used handguns, not AR-15s.
Thirty-five percent of the killers carried more than one weapon. Responders should not drop their guard if the killer appears to be disarmed of his primary weapon.
Most of the active killer attacks took place in commercial businesses. We hear a lot about shootings at concerts, schools, and churches. Those are comparatively rare. Most of the attacks in the study were in businesses open to the public. A lot of those attacks are perpetrated by employees and should better be considered “workplace violence” incidents rather than active killer events.