The most exhaustive report yet on the May 24 mass shooting inside a Uvalde, Tex., elementary school spread blame across every law enforcement agency responding to the attack, faulting local police for mistakes and more experienced agencies for failing to take charge.

Nearly 400 local, state and federal law enforcement officers were at the scene that day, including 91 state troopers — none of whom took the initiative to lead the response, the Texas House investigative report said. The school district police chief, Pedro “Pete” Arredondo, wrote its active shooter response plan and assigned himself as incident commander, but did not follow the protocol he had set up, the report said.

The report said it was not clear whether lives could have been saved with a swifter response, but left open the possibility.

“The void of leadership could have contributed to the loss of life as injured victims waited over an hour for help, and the attacker continued to sporadically fire his weapon,” says a portion of the report obtained by The Washington Post.

Rather than isolate blame on local officers, as some had since the shooting, the report casts a broader net of responsibility over “the entirety of law enforcement … on that tragic day.”

“Hundreds of responders from numerous law enforcement agencies — many of whom were better trained and better equipped than the school district police — quickly arrived on the scene,” the report says. “Those other responders, who also had training on active shooter response and the interrelation of law enforcement agencies, could have helped to address the unfolding chaos. Yet in this crisis, no responder seized the initiative.”

Nineteen students and two teachers died in the fusillade by 18-year-old Salvador Ramos, who was killed when police broke into a classroom after a long delay.

“Other than the attacker, this report did not find any ‘villains’ in the course of its investigation. There is no one to whom we can attribute malice or ill motives,” the report said. “Instead, we found systemic failures and egregious poor decision making.”

Uvalde survivors and their families were given a paper copy of the report Sunday morning and were to be briefed on it this afternoon.

Led by state Rep. Dustin Burrows (R), the House committee interviewed three dozen people and reviewed hours of audiovisual evidence, deposing everyone from Mayor Don McLaughlin to the 911 dispatcher, the school custodian and Arredondo. Some initially resisted interview requests, including Uvalde police officers and Uvalde County Sheriff Ruben Nolasco, but after some negotiation, they all relented.

The committee, which also included former Texas Supreme Court justice Eva Guzman (R) and El Paso state Rep. Joe Moody (D), worked through several media leaks and damning disclosures by the director of the Texas Department of Public Safety director, Steven C. McCraw. All of the interviews were held behind closed doors as the committee stepped gingerly around an ongoing criminal investigations by the Texas Rangers, the FBI and Uvalde District Attorney Christina Busbee.

Report authors said their focus was to bring much-needed answers to Uvalde families struggling to trust anyone with authority in the state of Texas amid competing narratives about how their children and teachers were killed.

A grisly checklist and a sickening rampage: Inside the Uvalde massacre

From the beginning, state troopers peddled false information to the media and officials at the scene, saying police had confronted the gunman early outside the school, were injured and followed him inside. The governor initially praised the police response, then said he was misled. McCraw later unveiled a timeline, outlining a delayed response full of bewildering errors by the incident commander, Arredondo, who disputed the characterization in an interview with the Texas Tribune. McLaughlin, the mayor, accused the state of pinning blame on their town. Texas State University researchers briefed by the Department of Public Safety found Uvalde police had a chance to stop the massacre.

Then came the leaked video. It begins with a pickup truck crashing into a dry drainage ditch outside the school and a black-clad Salvador Ramos emerging. He jumps over a fence and walks unobstructed into the school, rifle in hand and firing off a few rounds. In a version published by the Austin-American Statesman, the 911 call of a terrified teacher is heard over the images as she relays her horror and orders students back into their classrooms.

Explosions of gunfire follow as the shooter disappears into a classroom; audio of the screams was edited out. The time code from the fish-eye hallway camera showed police responded three minutes later and headed toward the violence. But rapid shots sent them retreating further down the hallway. They remained in that posture for nearly 77 minutes as more law enforcement officers and equipment filled the hallway. At one point, a helmeted officer spritzed his hands with sanitizer from a dispenser.

What we know about the victims of the school shooting in Texas

But none of the details released before Sunday did much to assuage the devastation of the survivors, some of whom had sought to rescue their children on May 24 — only to be impeded by law enforcement.

Burrows has said the investigative mandate was not to bring charges but to bring clarity to the events of that day and make legislative recommendations.

After similar mass shootings in Texas, the state legislature has pumped money into school safety enhancements and some mental health and counseling programs. But lawmakers have consistently loosened restrictions on guns like the one 18-year-old Ramos used at Robb Elementary School. Parents of those killed and injured have called on state and federal leaders to raise the purchase age for high-powered weapons like the one he used, which have become a fixture of mass shootings.

Deadly attacks like the Uvalde rampage routinely prompt after-action reviews, which study what happened, examine how law enforcement responded and highlight lessons that could be learned.

Ever since the Columbine High School massacre in 1999, law enforcement officials have been taught to go after gunmen quickly during active attacks to stop the threat, rather than waiting for specialized backup, such as SWAT teams.

“The longer the perpetrator is left to shoot, the more people may be killed or injured,” says an after-action report on the 2012 Aurora, Colo., movie theater shooting.

In multiple cases, reviews have identified communication issues they said cropped up when police responded to ongoing carnage. A state commission investigating the 2018 massacre at a Parkland, Fla., high school described “a severe radio failure which hindered communications.” Similarly, a state commission reviewing the Columbine shooting had described an “inability to communicate” among different agencies responding because “nearly all their radios operated on different bandwidths.”

Following the Washington Navy Yard shooting in 2013 in which 12 were killed, a review noted that some responding officers lost radio communications inside the building, while others could not “transmit vital information to one another due to the heavy radio traffic.” Confusion amid the chaos of an active attack has also been a recurring theme in some reports. After a gunman opened fire in the Fort Lauderdale airport in 2017, killing five people, a review found issues with communications as well as uncertainty about who was in charge.

Law enforcement officials have also faced criticism for their responses. After the Parkland massacre, the Broward County Sheriff’s Office acknowledged that one of its deputies had been working as a school resource officer but remained outside rather than confronting the shooter.

The state commission that investigated the Parkland shooting said other officers had failed to act promptly. In its report, the commission said “several” deputies from the Broward sheriff’s office were filmed or described taking time to put on ballistic vests, “sometimes in excess of one minute and in response to hearing gunshots.”

The report also said several deputies arrived near the school, and while most heard gunfire, they remained on the street “and did not immediately move toward the gunshots to confront the shooter.”

Reports have also highlighted the fraught scenes that responding officers encountered. A review of the law enforcement response to a 2015 terrorist attack in San Bernardino, Calif., described officers searching room after room for the shooters and eventually coming to the final unopened doors, expecting to find the shooters hiding inside.

“I don’t want to say I made peace,” one officer said, according to the report, “but I was ready to go.”

When they went into the final room, the officer said, “I was never so excited to not see anybody.” Police later tracked down the attackers’ vehicle and killed them in a shootout on a residential street.