In its report this week on the deadly school shooting in Uvalde, Texas, Justice Department officials strongly criticized the local police and issued blunt, unambiguous guidance for the future: Officers must rapidly confront a gunman, even if it costs them their lives.

The rebuke reflected the department’s frustration with the failure of police officials in the deadly 2022 shooting to observe protocols developed over the past two decades, and intended to address the threat of gunmen armed with battlefield-grade guns that can quickly kill dozens of people.

Most other types of police training emphasize careful, coordinated action to minimize the loss of life. But active-shooter protocols ask officers to abandon their civilian mind-set and transform, in an instant, into a kind of warrior posture.

Federal investigators said the decision to not rapidly confront the gunman was the single biggest failure of leadership and training during the attack at Robb Elementary School in Uvalde. It took 77 minutes for officers to enter the classrooms where the gunman had killed 19 students and two teachers, and fatally shoot him.

The shortfall in the response has been highlighted in several inquiries into the massacre. But in the time since the killings, officer training on active-shooter events has not been substantially revised to address the chaotic decision-making that led to the slow response, according to several policing experts. And it remained unclear how many of the nation’s roughly 18,000 law enforcement agencies, most of them small and rural like those in Uvalde, would do better.