(NewsNation) — The director of the Texas Department of Public Safety condemned the police response to a shooting at a Uvalde elementary school that killed 21 people as an “abject failure,” saying that police never checked a door to a classroom the gunman was in to see if it was locked.

According to Reuters, Col. Steve McCraw, director of the Texas Department of Public Safety, said the door was not locked, even as police waited for a key.

McCraw testified Tuesday at a state Senate hearing on the police handling of the tragedy. He told the Senate committee that enforcement authorities had enough officers on the scene of the Uvalde school massacre to have stopped the gunman three minutes after he entered the building.

Instead, police officers with rifles stood and waited for over an hour before they finally stormed the classroom and killed the gunman, putting an end to the May 24 attack that left 19 children and two teachers dead. The classroom door, it turned out, could not be locked from the inside, yet there is no indication officers tried to open it, McCraw said, adding that police waited around for a key.

“I have great reasons to believe it was never secured,” McCraw said. ”How about trying the door and seeing if it’s locked?”

Plainville, Conn. Police Chief Christopher Vanghele, a former police officer in Newtown where the Sandy Hook massacre occurred in 2012, told NewsNation the police response in Uvalde “boggled the mind.”

“They took an oath that their life would be sacrificed for others if it came down to that, that’s what we knew at Sandy Hook,” Vanghele said. “And I’ll tell you the teachers in Uvalde that died, I guarantee you they died while trying to protect those children, They didn’t have bulletproof vests, they didn’t have guns, they didn’t have ballistic shields… all they had was their bodies.”

Pete Arredondo, the Uvalde school district police chief, decided to put the lives of officers ahead of the lives of children, McCraw testified.

“Obviously, not enough training was done in this situation, plain and simple. Because terrible decisions were made by the on-site commander,” McCraw said of Arredondo.

The decision by police to hold back went against much of what law enforcement has learned in the two decades since the Columbine High School shooting in Colorado in which 13 people were killed in 1999, McCraw said.

“You don’t wait for a SWAT team. You have one officer, that’s enough,” he said. He also said officers did not need to wait for shields to enter the classroom. The first shield arrived less than 20 minutes after the shooter entered, according to McCraw.

Vanghele delivered a scathing review of the police officers responding to the Robb Elementary shooting, saying they were “cowards” and “as far as I’m concerned everyone of them should be fired.”

“They can no longer be officers because at the most basic level they’re not willing to put themselves at risk for their people,” Vanghele said. “What other type of a test do you need to prove it then you’re sitting there listening to children get killed and you don’t even try to stop it.”

Also, eight minutes after the shooter entered, an officer reported that police had a “hooligan” crowbar that they could use to break down the classroom door, McCraw said.

The public safety chief outlined for the committee a series of missed opportunities, communication breakdowns and other mistakes, among them:

— Arredondo did not have a radio with him.

— Police and sheriff’s radios did not work inside the school; only the radios of Border Patrol agents on the scene worked inside the school, and even they did not work perfectly.

— Some diagrams of the school that police were using to coordinate their response were wrong.

State police initially said the gunman entered the school through an exterior door that had been propped open by a teacher, but McGraw said that the teacher had closed the door and it could only be locked from the outside.

“There’s no way for her to know the door is locked,” McGraw said. “He walked straight through.”

This comes after the Austin American-Statesman revealed in an article that multiple police officers stood in a hallway at Robb Elementary School armed with rifles and at least one ballistic shield within 19 minutes of a gunman arriving at the campus, according to documents reviewed by the newspaper.

The series of revelations, which began the same week as the May 24 mass killing, has left the impression of a bumbling law enforcement response.

The newspaper cited documents, including school surveillance and police body camera video, from unidentified investigators of the May 24 massacre.

The timeline the American-Statesman reported from the documents included footage from inside the school that showed the 18-year-old gunman casually entering a rear door at 11:33 a.m., walking to a classroom and immediately spraying gunfire before barricading himself. Video showed 11 officers entering the school three minutes later, the newspaper reported.

Arredondo called the Uvalde Police Department landline and reported that their suspect had “shot a lot” with an AR-15-style rifle and outgunned the officers at the school, who he said were armed only with pistols, the newspaper reported.

Four minutes later, at 11:44 a.m., body camera video recorded the sound of more gunshots. At 11:52 a.m., the first ballistic shield arrived as officers grew impatient to act.

Another officer with a ballistic shield arrived at 12:03 p.m., and another came with a shield two minutes later. About 30 minutes before officers finally breached the classroom door at 12:50 p.m., Arredondo is heard wondering aloud if the gunman could be shot through a window. Only at 12:46 p.m. did Arredondo tell the tactical team members to breach the door when ready, the newspaper reported.

Delays in the law enforcement response have been the focus of the federal, state and local investigation of the massacre and its aftermath.

Vanghele said even if Arredondo’s leadership was poor that day, any of the other officers could have taken it upon themselves to enter the classroom and try to save the children, something he said police didn’t have a chance to do at Sandy Hook.

During Tuesday’s hearing, McCraw said police so far haven’t found anything that would be a red flag in the shooter’s school disciplinary files but learned through interviews that he engaged in animal cruelty. “He walked around with a bag of dead cats,” McCraw said.

In the days and weeks after the shooting, authorities gave conflicting and incorrect accounts of what happened, sometimes withdrawing statements hours after making them. But McCraw assured lawmakers: “Everything I’ve testified today is corroborated.”