Watch Uvalde school shooting video obtained by Statesman showing police response

The gunman walks into Robb Elementary School unimpeded, moments after spraying bullets from his semi-automatic rifle outside the building and after desperate calls to 911 from inside and outside the Uvalde school.

He slows down to peek around a corner in the hallway and flips back his hair before proceeding toward classrooms 111 and 112.

Seconds later, a boy with neatly combed hair and glasses exits the bathroom to head back to his class. As he begins to turn the corner, he notices the gunman standing by the classroom door and then firing his first barrage.

The boy turns and runs back into the bathroom.

The gunman enters one of the classrooms. Children scream. The gunfire continues, stops, then starts again. Stops, then starts again. And again. And again.

It is almost three minutes before three officers arrive in the same hallway and rush toward the classrooms, crouching down. Then, a burst of gunfire. One officer grabs the back of his head. They quickly retreat to the end of the hallway, just below a school surveillance camera.