A new wave of anger swept through Uvalde on Tuesday over surveillance footage of police officers in body armor milling in the hallway of Robb Elementary School while a gunman continued firing inside a fourth-grade classroom where 19 children and two teachers were killed.

The video published Tuesday by the Austin American-Statesman is a disturbing 80-minute recording of what has been known for weeks now about one of the deadliest school shootings in U.S. history: that heavily armed police officers, some armed with rifles and bulletproof shields, massed in the hallway and waited more than an hour before going inside and stopping the May 24 massacre.

But the footage, which until now had not surfaced publicly, anguished Uvalde residents anew and redoubled calls in the small South Texas city for accountability and explanations that have been incomplete — and sometimes inaccurate — in the seven weeks since the shooting. Hours after the video was published, residents at a Uvalde City Council meeting shouted for action and demanded that police face consequences.

An investigative committee led by Texas lawmakers had earlier announced plans to show the video to Uvalde residents for the first time Sunday, in addition to sharing their findings after weeks of closed-door testimony from more than 40 witnesses.

"This has been the most unprofessional investigation or handling of it that I've ever seen in my life," Uvalde Mayor Don McLaughlin said in an interview with The Associated Press. "These families get blindsided constantly."

The footage from a hallway camera inside the school shows the gunman entering the building with a AR-15 style rifle and includes 911 tape of a teacher screaming, "Get down! Get in your rooms! Get in your rooms!"

Two officers approach the classrooms minutes after the gunman enters, then run back amid the sounds of gunfire.

As the gunman first approaches the classrooms a child down the hallway can be seen poking their head around the corner and then running back while shots ring out. Later, about 20 minutes before police breach the room, the video shows a man wearing a vest that says "sheriff" use a hand sanitizer dispenser mounted on the wall.

Officials said the 77 minutes of footage they are preparing to release this weekend does not contain images of children in the classroom. Rep. Dustin Burrows, a Republican who is leading the investigation, said after the video was posted by the Statesman that "watching the entire segment of law enforcement's response, or lack thereof, is also important."

But the video alone does not answer all the questions that remain, nearly two months later, about the law enforcement response. Among them are how schools police Chief Pete Arredondo came to the forefront of the massive law enforcement response involving numerous local, state and federal agencies.

State authorities have cast Arredondo as the on-scene commander and said his errors delayed police killing the gunman. Arredondo, however, has told the Texas Tribune he didn't consider himself to be in charge of operations and that he assumed someone else had taken control of the law enforcement response. He did not have a police radio at the time.

The roles of the ranking on-scene officers from other agencies, including the Texas Department of Public Safety, remain unclear. Local officials in Uvalde have accused the state police of repeatedly putting out inaccurate information about the shooting while glossing over the role of its own troopers.

McLaughlin has accused DPS of minimizing its involvement in the response and releasing inaccurate timelines and series of events. Last week, a critique of the police response written by tactical experts and requested by DPS alleged that a Uvalde police officer had a chance to open fire on the gunman before he entered the school. McLaughlin has said that account was inaccurate,

"All they keep doing is piling missed facts on missed facts, and throwing it out there and see what sticks," McLaughlin said.

In a statement, DPS Director Steve McCraw said the video provides "horrifying evidence" that the law enforcement response was a failure.

- By ACACIA CORONADO and PAUL J. WEBER Associated Press