The FBI study states:
....many incidents ended before police arrived. Of the 160 incidents, at least 107 (66.9%) ended before police arrived and could engage the shooter, either because a citizen intervened, the shooter fled, or the shooter committed suicide or was killed by someone at the scene.
The numbers show that police are too slow 2 out of 3 times and police often take casualties when they do get there in time. Armed citizens are quicker to respond and have a much better success rate. If armed citizens take action, the event will probably be resolved by the time on-duty police get to the scene. Mr. Suarez has additional advice in his book.
Until other instructors publish their own books on active shooter interdiction and open up training to the license-to-carry community, Mr. Suarez will be the leader in the area because he doesn't have any direct competition on the subject.
I wish there was more of this training available. Krav Maga, Haganah
, and jiu-jitsu can fill in some of the gaps.