The police chief in charge of the response to last week’s deadly attack at a Texas primary school was not carrying a radio as the massacre unfolded, a state senator has told The Associated Press, citing the state agency investigating the mass shooting.

Senator Roland Gutierrez told the news agency on Friday that a Texas Department of Public Safety official told him school district police Chief Pete Arredondo was without a radio during the May 24 attack.

Authorities say an 18-year-old gunman barricaded himself inside a fourth-grade classroom at Robb Elementary School in Uvalde, Texas, and began firing indiscriminately, killing 19 children and two teachers and injuring 17 others.

Authorities have not said how other law enforcement officials were communicating with Arredondo on the scene. Arredondo heads the district’s small department and was in charge of the multi-agency response to the shooting.

The attack was the deadliest school shooting in the United States in a decade, spurring public anger and renewing calls for Congress to pass stricter gun laws in a country where mass shootings are frequent.

Parents and other relatives of the victims also have demanded answers over why police did not immediately enter the classroom as the shooting was unfolding.

A group of 19 officers stood for about 45 minutes in the hallway before US Border Patrol agents unlocked the classroom door to confront and kill the gunman.

“With the benefit of hindsight … from where I’m sitting right now, of course, it was not the right decision. It was the wrong decision [to wait]. There’s no excuse for that,” a Texas official acknowledged last week.

Arredondo, who has drawn much of the criticism over law enforcement’s handling of the attack, has not responded to multiple interview requests from AP since the shooting, including a telephone message left with the school district police on Friday.

“I feel like we all failed these children,” Gutierrez, a Democratic state senator who represents Uvalde, told MSNBC in an interview.

Meanwhile, relatives of victims and survivors of the shootings in Uvalde and Buffalo, New York – where a gunman killed 10 Black people at a grocery store last month – will testify before a House of Representatives committee next week about the devastating effects of US gun violence.

Women embrace as people gather at the memorial at Robb Elementary School in Uvalde, Texas

Representative Carolyn Maloney, the chairwoman of the Oversight Committee, said the hearing on Wednesday will examine the human effect of gun violence and the urgency for lawmakers to enact gun control legislation.

“It is my hope that all my colleagues will listen with an open heart as gun violence survivors and loved ones recount one of the darkest days of their lives,” Maloney said in a statement on Friday. “This hearing is ultimately about saving lives, and I hope it will galvanize my colleagues on both sides of the aisle to pass legislation to do just that.”

US President Joe Biden has urged lawmakers to pass stricter gun control measures, including a ban on assault weapons that was allowed to lapse under a Republican administration in 2004.

Other proposals include a limit on high capacity magazines, secure storage laws, “red flag” laws, universal background checks, and the removal of protection laws for gun manufacturers.

“It’s time to act,” Biden said in an emotional address that was broadcast live to the nation on Thursday evening. “For the children we have lost. For the children we can save. For the nation we love. Let’s meet the moment. It’s time to act.”

In a tweet on Friday, Biden also said the US should “repeal the liability shield that often protects gun manufacturers from being sued for the death and destruction caused by their weapons”, calling that protection “outrageous”.

Back in Uvalde, the father of a 10-year-old girl slain in the Uvalde shooting and a school employee have taken initial steps that could lead to lawsuits against Daniel Defense, the maker of the semiautomatic rifle used in last week’s massacre that killed 21 people.

Lawyers for Alfred Garza, father of Robb Elementary School student Amerie Jo Garza, requested in a letter on Friday to Daniel Defense that the Black Creek, Georgia-based gun manufacturer provide information about its marketing to teens and children.

“We ask you to begin providing information to us now, rather than force Mr. Garza to file a lawsuit to obtain it,” his lawyers wrote in the letter.

Separately, school employee Emilia Marin filed papers in Texas state court seeking an order to depose Daniel Defense and force the company to turn over documents, also related to its marketing. Marin is listed as a speech pathologist clerk on the school’s website.

Marin’s filing late on Thursday is a petition that allows a party to begin investigating potential claims.

No lawsuits have yet been announced against Daniel Defense stemming from the shooting. Daniel Defense did not immediately respond to a request for comment from Reuters.