Uvalde officers failed to follow active shooter training they received two months prior to massacre that killed 21

Baber revealed the news via Twitter Friday evening with an unsettling set of posts.

Photos of internal documents revealed police did not follow their training, some of which was as recent as two months prior to the shooting.

"I have spent the last few days researching the training of Uvalde officers, including the tactics they were expected to use to halt school shooters," Baker wrote.

He explained in the past year, Uvalde law enforcement received at least two training days on this exact scenario, accounting for what to do with a limited response team, personnel, and time.

One document outlines the importance of quick action.

"The short duration and high casualty rates produced by these events require immediate response to reduce the loss of life. In many cases that immediate response means a single (solo) officer response until such a time as other forces can arrive. The best hope that innocent victims have is that officers immediately move into action to isolate, distract, or neutralize the threat, even if that means one officer acting alone."

The documents are especially damaging in light of recent discoveries that the police chief and other law enforcement remained outside the building and prevented other responders from confronting the shooter. The squad of border security agents that eventually dispatched the shooter waited 30 minutes before defying orders and entering the building.

The delay was confusing, especially to onlooking parents. When Texas Governor Greg Abbott learned law enforcement had not immediately taken action to confront the shooter, he didn’t hide his frustration.

"I am livid about what happened," Abbott said. "I was on this very stage two days ago, and I was telling the public information that …turned out in part to be inaccurate. I am absolutely livid about that."

Baker’s discovery adds to a growing pile of evidence suggesting the 40-minute wait could have been eliminated.