Texas state police are adopting a more aggressive strategy for responding to school shootings after scathing criticism of law enforcement for its handling of a massacre in Uvalde that killed 19 children and two teachers, the New York Times reported.

The Texas Department of Public Safety (DPS) has also referred five of its officers to the state inspector general for investigation into their actions during the May 24 shooting at Robb Elementary School, the Times reported on Tuesday. Two have already been suspended, the newspaper reported, citing an agency spokesperson.

Texas police were not immediately available for comment.

The new policy and investigation are the latest indications that state police officials, including DPS Director Steven McCraw, have acknowledged that more than just local law enforcement were responsible for the failed police response during the deadliest U.S. school shooting in nearly a decade.

The officers under investigation were identified during a review by the agency, which includes the Texas Ranger division, of how its officers responded to the shooting in Uvalde, a small town in Texas Hill Country, about 80 miles (129 km) west of San Antonio.

Also in July, McCraw sent an email outlining changes in the protocol for DPS officers responding to a mass shooting, the New York Times reported.

"Officers responding to an active shooter at a school will be authorized to overcome any delay to neutralizing an attacker," McCraw wrote. "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.'"

In the wake of the shooting, criticism of law enforcement's response has centered on Pete Arredondo, the school district's embattled police chief. According to the Texas DPS, Arredondo acted as "incident commander" in charge of the overall response. Last week, the Uvalde school board fired Arrendondo.

DPS officials said 19 officers waited for an hour in a hallway outside adjoining classrooms where the gunman was holed up with his victims before a U.S. Border Patrol-led tactical team finally made entry and killed the suspect.

McCraw said the new policy diverged from the approach recommended by the Advanced Law Enforcement Rapid Response Training Center at Texas State University, a protocol that the Texas state police and departments around the country have generally followed.

"We will provide proper training and guidelines for recognizing and overcoming poor command decisions at an active shooter scene," McCraw wrote, according to the Times.

A report by state lawmakers, released in July, said a total of 376 law enforcement officers, including more than 90 state police offices, rushed to the school in a chaotic scene marked by a lack of clear leadership and sufficient urgency.