Active Shooter Events

Friday, March 14th, 2014

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.


  1. Jehu says:

    People who are not exceptionally well trained or experienced tend to operate according to scripts in combat, assuming that they are capable of acting effectively at all. Taking them ‘off script’ is pretty devastating to their effectiveness. A CCW holder interfering with their plans is usually enough to derail them, even if they can’t hit the broad side of a barn. There’s a reason nearly all such shootings now (the successful ones) take place where CCW is forbidden.

  2. William Newman says:

    Even for the ones which are well trained, I bet a lot of what’s going on is making the scripts cover more of the likely possibilities, not getting away from operating on scripts entirely. Some fraction of what happens when people get good at things I know well (games like Chess and Go, various branches of math and programming, a bit about mixed martial arts) is foundational things like physical conditioning and learning the principles better. But a fair amount is also getting really good at things that tend to arise regularly. Notice how even a minor changeup like competing with a lefthander can increase friction significantly even for someone who’s very experienced. I can’t think of really good examples for major changeups that have been encountered many times, but I’d expect they’d increase friction a lot even for people who are very experienced. Deciding things in a hurry is hard.

    (A marginal example: getting a strong chess player out of his opening book doesn’t mean his next move won’t be strong, but it may be a heckuva lot less strong than the preceding ones.)

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