I’m not a cop, nor military- but in a case where you have casualties waiting for rescue, don’t you first secure an area where you know the shooter(s) isn’t, and start working on victims there?
Yes. Hubby is a retired firefighter. They always wait on the police for safety reasons.
An active shooter killing children is not a military engagement. Securing the perimeter increases the death toll. Engaging the shooter is the first priority in protecting children.
The life of an LEO is not of greater value than the child he is bound to protect. It is always better for emergency personnel to absorb bullets than to allow those same bullets to kill children.
The police on site had the absolute moral obligation to die protecting children. There were teachers and students who understood this clearly.