The Texas Department of Public Safety Monday announced that an internal review was underway into the law enforcement response to the Uvalde, Texas, school shooting “to determine if any violations of policy, law, or doctrine occurred.” This follows the release of a report into the response by the Texas House of Representatives on Sunday.

The Investigative Committee on the Robb Elementary Shooting’s preliminary report found that lapses in judgment made by law enforcement leadership and unsafe day-to-day practices by school officials likely contributed to the deaths of 19 students and two teachers.

The committee’s evidence comes from private interviews with 35 witnesses and 39 independent informal interviews. It also includes audio and video footage, school safety protocols, and police training modules.

The report found that the school often left exterior and classroom doors unlocked, contrary to school policy, and that the classroom door where the shooting happened was widely known to be broken and was probably not locked as it should have been in an active shooter situation.

“Because of these failures of facilities maintenance and advance preparation, the attacker fired most of his shots and likely murdered most of his innocent victims before any responder set foot in the building,” said the report.

The report also found that police officers improperly treated the situation as a “barricaded subject” scenario, where the gunman has barricaded himself in a classroom with the victims, rather than an “active shooter” scenario. As a result, they chose to wait over 40 minutes for a key rather than breach the room by force.

This behavior is inconsistent with the officers’ active shooter response training, which is reviewed in the report. The training reads, “Often, the quickest, most discreet, and safest method of entering a locked building is to locate a key” but “if a key cannot be located quickly, [law enforcement] responders should use another technique to enter the area without delay.”

“Law enforcement responders failed to adhere to their active shooter training, and they failed to prioritize saving the lives of innocent victims over their own safety,” said the report. The report indicated that it was “plausible” that some victims could have survived had the police entered more quickly.

The report attributed the lack of leadership to then-Uvalde CISD Police Chief Pete Arredondo, who it said failed to execute or assign command and instead remained in the building without his radio. The committee also concluded that subordinate officers should have approached Arredondo for leadership when it was not given.

Arredondo’s lawyer, George Hyde, previously told the Texas Tribune that breaching the attacker’s location would have been a “reckless and ineffective” action, and Arredondo said, “Not a single responding officer ever hesitated, even for a moment, to put themselves at risk to save the children.”

The report also states that the shooter was unsuccessful in asking family members to purchase guns for him when he was underage. At age 18, he was able to pass background checks and buy weapons legally.

The US Department of Justice is also currently investigating the law enforcement response to the shooting, focusing on police response time.