DALLAS — Police officers were in the hallway and armed with rifles and at least one ballistic shield within 19 minutes after a gunman arrived at Robb Elementary School in Uvalde, a new development that raises more questions and criticism about law enforcement’s response to the massacre, according to a new report from The Austin American-Statesman.

Authorities reconstructed a timeline of the May 24 shooting using footage from inside the school and body camera video from more than a dozen officers, according to the American-Statesman.

Investigators say the latest information indicates officers had more than enough firepower and protection to take down the gunman, the American-Statesman reported. The shooter, an 18-yearold who walked into the school with an AR-15, killed 19 children and two teachers.

The new information is expected to be presented at a Texas Senate hearing Tuesday, the American-Statesman reported, which will give members of the public an opportunity to address lawmakers on gun violence and other related issues.

According to footage from inside the school, the gunman entered the building through a rear door, walked into a classroom and fired into the classroom before barricading himself, the American-Statesman reported.

The reconstructed timeline showed that officers breached the classroom at 12:50 p.m. The shooter entered the classroom at 11:33 a.m., the American-Statesman reported.

Documents reviewed by the American-Statesman showed 11 officers entered the school within three minutes of the gunman.

Pete Arredondo, chief of the Uvalde school district police force, called the Uvalde Police Department for help at 11:40 a.m., the American-Statesman reported.

At 11:44 a.m., body camera footage detected more shots from the gunman. At 11:52 a.m., an officer with the first ballistic shield entered the school as other officers grew increasingly impatient, according to the American-Statesman.

“If there’s kids in there, we need to go in there,” one officer said.

Another officer responded, “Whoever is in charge will determine that.”

A transcript of officers’ body camera footage showed Arredondo was trying to find keys to open the classroom door, the American-Statesman reported. Officials have said that they do not believe officers had tried to open the door.

At 12:03 p.m., an officer with another ballistic shield entered the school, and a third arrived two minutes later.

The new information shows Arredondo also tried to speak to the gunman, asking him whether he could hear him.

At 12:46 p.m., Arredondo told SWAT officers they should breach the classroom door if they were ready, the American-Statesman reported. Footage shows that medical units had arrived and were tending to children in the hallway after the gunman was dead.

Arredondo has come under scrutiny from both state officials and experts trained in mass shooting responses. Texas Department of Public Safety Director Steven McCraw has said that Arredondo, who he described as the incident commander, made the “wrong decision” to not order officers to breach the classroom more quickly to confront the gunman.

Arredondo said that he did not consider himself the person in charge as the massacre unfolded and assumed someone else had taken control of the law enforcement response.

Records obtained by The New York Times show the gunman had a “hellfire” trigger device meant to allow a semiautomatic AR-15-style rifle to be fired more like an automatic weapon but did not appear to have used it during the attack.

The gunman had spent more than $6,000 amassing an arsenal of weapons that included two AR-15-style rifles, accessories and hundreds of rounds of ammunition, according to the documents.

According to the agenda for this week’s hearings, there is no mention of limiting access to firearms.