▶ Watch Video: Uvalde students return to school after mass shooting

Five officers with the Texas Department of Public Safety (DPS) are under investigation for their response to the mass shooting at Robb Elementary School in Uvalde in which 19 students and two teachers were killed, the agency announced Tuesday. The announcement comes as Uvalde students returned to school for the first time since the attack.

DPS said that it has referred the five officers to the state Office of Inspector General for a “formal investigation into their actions into their actions that day.”

Two of the five officers have already been suspended without pay while the investigation plays out, DPS said. The five officers were not identified.

The agency Tuesday also released an internal employee memo that was sent in July by DPS Director Steven McCraw.

In it, McCraw wrote that — in response to the Uvalde shooting — the agency had made an “addition” to what is known as the Advanced Law Enforcement Rapid Response Training (ALERTT) doctrine, a program the state uses to train its officers on how to respond to active shooter situations.

“DPS officers responding to an active shooter at a school will be authorized to overcome any delay to neutralizing an attacker,” McCraw wrote in the memo to employees. “When a subject fires a weapon at a school he remains an active shooter until he is neutralized and is not to be treated as a ‘barricaded subject.’ We will provide proper training and guidelines for recognizing and overcoming poor command decisions at an active shooter scene.”

During testimony at a state Senate hearing back in June, McCraw called the response to the shooting an “abject failure.”

According to an extensive report into the shooting released in July by a special committee convened by Texas lawmakers, a total of 376 law enforcement officers responded to the May 24 shooting at Robb Elementary. However, while the gunman was barricaded inside a classroom, surveillance video showed a group of those officers waiting in a hallway.

According to the report, from the time the first officers arrived on the scene, it took them 73 minutes to breach the classroom, confront and fatally shoot the suspect. 

Most of the shooting victims “perished immediately,” the committee wrote in its report, although it added that it is “plausible some of the victims could have survived if they had not had to wait 73 additional minutes for rescue.”

Pete Arredondo, the police chief of the Uvalde Consolidated Independent School District at the time of the shooting who was in charge of the law enforcement response to the attack, was fired by the school board last month.