Two decades of shooter response strategy ignored in Uvalde

A total of 376 officers converged on Robb Elementary School, more than the entire police force in a mid-size American city like Fort Lauderdale, Florida, or Tempe, Arizona. But for more than 70 minutes, not one stopped the shooter.

Amid the sounds of continuing gunfire emanating from the elementary school they waited. By the time they entered and killed 18-year-old Salvador Ramos, 19 children and two teachers were dead or mortally wounded.

The response counters active-shooter training that emphasizes confronting the gunman, a standard established more than two decades ago after the mass shooting at Columbine High School showed that waiting cost lives.