The FBI’s report on Active Shooter Events from 2000 to 2012 notes that private citizens stopped one in six mass shootings:
Note that for the purposes of the study, the average police response time was about 3 minutes. Out of 104 incidents, they had the following resolution:
- 49% of events stopped before the police could arrive
- 42% of events (44 total) resulted in the killer committing suicide, of which 29 killers committed suicide prior to police arrival.
- 43% of events (45 total) result in the attacker being stopped with force, either by civilians or law enforcement.
- When civilians intervene before LE arrives, they stop 33% of mass shootings.
- Slightly less than 3% of mass shootings are stopped by armed civilians shooting the attacker.