A new video released of the horrific massacre in Uvalde, Texas, shows how quickly the killer was able to enter the elementary school and what the police response was minutes later.
The video was obtained by the Austin American-Statesman and KVUE-TV and published on Tuesday.
The footage documents a phone call from a teacher to 911 about the shooter. She frantically yells that children are running while shots are heard. She then yells at children to stay in their classrooms.
The video then shows the killer, Salvador Ramos, entering the school and going down the hall armed with his AR-15 rifle.
Here's the harrowing video of the Uvalde massacre:
Minutes later, the video shows police entering the school hallway and taking their positions.
The video will likely rekindle criticism against the police response to the shooting. Critics say there's evidence that the police could have acted earlier to accost the shooter and that could have possibly saved some lives that were lost.
Nineteen children and two teachers were killed in the massacre.
Among the more damaging revelations were comments by Uvalde School District Police Chief Pete Arredondo who admitted that he wasn't aware that he had been the commander in charge at the time of the attack. He also had limited information because he had purposely abandoned his radios at the beginning of the police response.
Republican Texas Gov. Greg Abbott called for more transparency in the wake of the criticism.
"Let me be clear and let me be adamant," said Abbott. "The full truth about what happened in Uvalde must be disclosed to the public, especially to the people of Uvalde, and must be done quickly."
A former co-worker of the killer later said that he had openly talked about his plans to save up his money to purchase guns on his 18th birthday. Other acquaintances said he was acting erratically before the shooting and had a troubled home life.
Here's more about the latest Uvalde development:
Uvalde hallway video to be released to community first www.youtube.com