Recently leaked security video from the Uvalde school massacre in May shows fully-armed police retreating and holding back for 74 minutes before they finally engaged the shooter.

Released Tuesday, the video shows several officers in the Robb Elementary School hallway moving to engage the shooter only to immediately retreat after being fired upon. Just 19 minutes after the shooting begins, police sporting ballistic shields arrive and yet still do nothing to engage the shooter for upwards of 50 minutes, during which officers can be seen checking their phones and wiping their hands with sanitizer.

A full 74 minutes pass before police finally breach the door and engage the shooter, who was killed by a Border Patrol Agent who was part of a makeshift team of federal, state, and local officers.

Nineteen children and two teachers were killed during the shooting while another 17 were wounded. According to a recent report from the Advanced Law Enforcement Rapid Response Training Center (ALERRT) at Texas State University, a Uvalde police officer even had the shooter in his rifle sight before he entered the school but held back while waiting for “permission to shoot.” The report said:

A Uvalde PD officer reported that he was at the crash site and observed the suspect carrying a rifle prior to the suspect entering the west hall exterior door. The UPD officer was armed with a rifle and sighted in to shoot the attacker; however, he asked his supervisor for permission to shoot.

“The UPD officer did not hear a response and turned to get confirmation from his supervisor. When he turned back to address the suspect, the suspect had already entered the west hall exterior door at 11:33:00,” it continued.

The report did, however, acknowledge that the officer was concerned that a bullet could have mistakenly “penetrated the school and injured students” if he had missed the shot.

“Ultimately, the decision to use deadly force always lies with the officer who will use the force. If the officer was not confident that he could both hit his target and of his backdrop if he missed, he should not have fired,” the report concluded.