It is unclear when the footage will be released.

State Rep. Dustin Burrows, the chairperson of a special legislative committee investigating the shooting, said officials had agreed to release surveillance footage inside the Robb Elementary hallway from the day of the shooting.

"This video would be of the hallway footage from Robb elementary school… it would contain no graphic images or depictions of violence," Burrows said.

The footage will document how cops stood back for 77 minutes as a lone gunman entered Robb Elementary School and killed 19 students and two teachers.

Officials have previously admitted that the situation could have been stopped within just three minutes after surveillance footage showed officers with rifles and at least one ballistic shield enter the school minutes after the gunman.

They were stopped by police chief Pete Arredondo, who claimed the suspect had barricaded himself inside. 

A law enforcement source told the San Antonio Express-News that surveillance footage from Robb Elementary School shows that police made no effort to open the door. The report further states there is reason to believe it may have been unlocked. 

According to the source, investigators believe the shooter who killed 19 children and two teachers at the school could not have locked the door to the connected classrooms from the inside.

The source said that all classroom doors at Robb Elementary are designed to lock automatically when closed. Police might have assumed the door was locked, but the latest evidence suggests it may have been open the whole time, possibly due to a malfunction.