Stupid article. The right response for non-law enforcement is to get the hell outta the building yesterday and to make damned sure that responding cops know you ain't the bad guy lest you wind up room temperature.
Do civilian training courses really teach pursuing bad guys and clearing buildings?
These two have a shtick that they're hustling to soldiers of fortune.
Law enforcement agencies have their methods of clearing buildings. Don't be around when they do. It might not work out for you if they're responding to an active shooter call.
Building clearing is something that ought to be taught, and something you should at least be competent with if you have kids and/or a large house.
To say you'll NEVER be in a position where you'll never need "building clearing skills" just shows no imagination whatsoever, and it's a plan to fail.
