[Red Steel]

Not really true. They go in immediately when the whole SWAT team arrives. And a supervisor. And the proper perimeter is established to make sure that the shooter can’t escape. I have a cop in my family and he told me that they aren’t John McClane. They aren’t even the donut cop outside.

It's what I've read here in Colorado where Columbine happened. I suppose you'd have to poll the PDs across the nation to get what their opinions and policies are about school shooters to get a good reading about the subject.

Waiting for SWAT to get there to respond would cost lives.

[Robert A Cook PE]

Waiting for SWAT “methods and approved tactics” got the 50+ homosexuals shot in the nightclub down in Miami.