The police response to the Robb Elementary School shooting in Uvalde, Texas, was an “abject failure,” as police lives were prioritized over those of students, according to a top Texas official.

“There is compelling evidence that the law enforcement response to the attack at Robb Elementary was an abject failure and antithetical to everything we’ve learned over the last two decades since the Columbine massacre,” said Col. Steve McCraw, director of the Texas Department of Public Safety.

“Three minutes after the subject entered the West building, there was sufficient number of armed officers wearing body armor to isolate, distract, and neutralize the subject. The only thing stopping the hallway of dedicated officers from entering room 111 and 112 was the on-scene commander who decided to place the lives of officers before the lives of children,” he said.

McCraw appeared at a public Texas Senate committee hearing investigating last month’s mass killing. The special committee began hearings on June 16 in Austin, according to The Dallas Express.

According to a timeline in surveillance footage exclusively obtained by The Austin American-Statesman and ABC News, multiple police officers armed with rifles and at least one ballistic shield entered Robb Elementary School 19 minutes after the shooting began.

Concerns have been raised about how police handled the May 24 shooting in Uvalde, where a gunman killed 19 children and two teachers. Law enforcement reportedly did not confront the gunman for more than an hour, despite pleas from distraught parents outside the school.

Footage from school cameras shows that the 18-year-old gunman casually entered a rear door shortly after 11:30 a.m., walked to a classroom, and immediately opened fire before barricading himself inside. According to reports, footage from those cameras and body cameras worn by responding officers shows 11 officers entering the school three minutes later.

The school district’s police chief, Pete Arredondo, called the Uvalde police department’s landline telephone and reported that the suspect had “shot a lot” with an AR-15 and “out-matched” the officers at the school, whom he said were armed only with pistols.

At 11:44 a.m., body camera video captured the sound of more gunshots. Shortly after, additional officers began responding to the scene, armed with ballistic shields. Also called tactical shields, these are handheld protective devices designed to stop or deflect bullets or projectiles.

The first officer with a ballistic shield arrived at 11:52 a.m., and officers grew impatient to act. According to ABC News, Arredondo struggled to find a key to the classroom, although no officer is believed to have attempted to open the door.

A second officer with a ballistic shield arrived at 12:03 p.m., followed by another two minutes later, ABC News reports. About 30 minutes before officers broke down the classroom door, Arredondo is heard wondering aloud whether law enforcement could shoot the gunman through a window.

Recently obtained video surveillance footage from the school did not show officers attempting to open the door into the classrooms where the massacre occurred, The San Antonio Express-News reported.

Two City of Uvalde police officers told a sheriff’s deputy that they passed up a brief opportunity to shoot at and potentially wound or kill the gunman while he was still outside the school because they were afraid of hitting children, Fox News reported.

Federal, state, and local investigations into the massacre and its aftermath have focused on the adequacy of law enforcement response and the reason for its delay.

As previously reported by The Dallas Express, McCraw stated that Arredondo made “the wrong decision” by choosing not to rush the classroom for more than 70 minutes, as trapped fourth-graders inside two classrooms desperately dialed 911 for assistance.

Arredondo, an alumnus of Robb Elementary School in his hometown of Uvalde, said that he feels he did everything he could to protect the lives of his neighbors.

“My mind was to get there as fast as possible, eliminate any threats, and protect the students and staff,” Arredondo said.