This is right.

[Joenobody]

The response to Columbine was to set up a parameter and wait. Almost like a barricaded suspect/hostage situation. However, it just gave the duo time to carry out the massacre. Since then standard response protocol is to make entry ad soon as possible. That doesn't mean first one there goes in like Rambo...but it does mean that first three or so there make entry as a team. There shouldn't be 40 minutes to time...it should be more like the 60 or so seconds it takes the first units to get there and establish a tactical entry

I dont feel like this was the only failure of police here either. It's pretty standard notify schools in the area of any potential violent crime or criminal and put them on lockdown. It doesn't seem like that was done. And does TX not have officers in schools? That's pretty standard in most schools now.