What Happens W/Armed Teachers When SWAT Responds?

In the chaos of a shooting incident, if you have a bunch of armed teachers in the area what is going to happen? How is an officer going to separate the good guys from the bad guys. Will the good guys be wearing beanies or some kind of uniform. Armed teachers are going to be mixed in with scared kids.

Armed teachers or good guys with guns in any shooting situation has to be chaos on steroids. There is not enough time to adequately separate who is not hostile. The first inclination is to shoot first and ask questions later. Plus I remember that one shooting where an officer drew down on the shooter at close range. In the end the officer missed and got shot.

And we must remember schools are just the one place where shootings happen. Every public venue in the country is a soft target. And even being on the street is a soft target. So I guess we would fortify schools but leave the rest of our public places as soft targets.

ADDENDUM BTW When I was in Vietnam we had a hard time separating the friendlies for the enemy during firefights at times. We even had trouble with friendlies operating in the same area. There were a lot of friendly fire incidents.