As authorities continue to releaseshifting timelinesof Tuesday’smass shootingat Robb Elementary School in Uvalde, Texas, one lawmaker has sent a letter to the FBI, demanding an investigation into the police response.

In his letter, Castro demanded answers about the various accounts that law enforcement agencies have given.

ALLISON DINNER/AFP via Getty

People sit on the curb outside of Robb Elementary School as State troopers guard the area in Uvalde, Texas, on May 24, 2022. - An 18-year-old gunman killed 14 children and a teacher at an elementary school in Texas on Tuesday, according to the state’s governor, in the nation’s deadliest school shooting in years.

Memorial for the 21 victims of the Uvalde school shooting.Elaine Aradillas

Uvalde victims memorial

While the timeline of the attack is still in flux, most law enforcement accounts agree that the shooter was in a classroom with the victimsfor more than 40 minutes. At a Friday press conference, Texas Department of Public Safety executive director Steven McCraw said it was the “wrong decision, period” for responding officers not to immediately enter the classroom the shooter was in. He said officers treated the call as one for a barricaded suspect and believed students inside were safe.

Several witnesses have talked to PEOPLE about the attack and police reponse.

Jordan Vonderhaar/Getty

UVALDE, TX - MAY 25: In this aerial view, law enforcement works on scene at Robb Elementary School where at least 21 people were killed yesterday, including 19 children, on May 25, 2022 in Uvalde, Texas. The shooter, identified as 18 year old Salvador Ramos, was reportedly killed by law enforcement.

“There was a lot of chaos,” says Ernest “Chip” King, a Uvalde firefighter who estimated that the gunfire went on for about 40 minutes. “Fathers smashed windows, and physically pulled their kids out of classrooms.”

For more on the shooting massacre at Robb Elementary School in Uvalde, Texas, listen below to our daily podcast PEOPLE Every Day.

Some relatives at the scene believe that police hesitation cost lives.

“Everyone was just showing up and they weren’t doing anything,” says Berlinda Arreola, 49, whose granddaughterAmerie Jo Garzawas killed in the attack. “The parents were being all crazy, like ‘Why aren’t you all doing anything? Why aren’t you going in?’ But they were like, ‘until he opens gunfire, we can’t do anything. We’re holding on so that he doesn’t open gunfire.'”

But Arreola tells PEOPLE that it was too late. “We didn’t know that he had already opened gunfire in there. We didn’t even know that he had already shot all the kids. It was already done.”

The FBI has not publicly responded to Rep. Castro’s letter.

source: people.com