Uvalde Police on Video Retreating from Gunman During School Massacre

New video shows the horrific scene inside the Uvalde school where a gunman murdered 19 children and 2 teachers, and you see the police try and approach the shooter and then run for cover when the gunman shoots at them.

KVUE TV obtained the surveillance video ... 3 minutes after the shooter entered the school and began firing rounds into 2 classrooms, you see the police enter the hallway inside the school and approach the door outside the classroom where the shooter was firing rounds at the children.

The shooter then begins firing rounds outside the classroom, presumably at the cops. The police then flee the immediate area and retreat a distance away ... looking for cover in the hallway.

Two cops touch their head and neck area, as if to see if they were shot.

For the next 45 minutes, you see reinforcements arrive ... but they never try to breach the classroom. They eventually set up right outside the classroom but don't attempt to enter for another 30 minutes. That's when they enter a classroom and they see the shooter emerging from a closet and a Border Patrol cop shoots him dead.