This week, a leaked surveillance video published by the Austin American-Statesman gave the world a glimpse at the horror that unfolded as a gunman entered Robb Elementary on May 24, making his way toward classrooms 111 and 112.
Arnulfo Reyes was in the former, watching a movie with his fourth-grade class when the shooting started.
"The kids start asking, 'What's going on?’ Because it's just very loud,” said Reyes.
Reyes said as gunshots grew louder, he instructed his students to hide under a table and pretend to sleep. Reyes did the same, even after the gunman shot him in the arm.
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"You start seeing pieces of the wall falling off -- like sheetrock flying everywhere,” he said.
From there, Reyes said he lost track of time.
“He tried to make me flinch, spilled water on my back, cold water. I had a cup on a table and he spilled it on me. I didn't move,” said Reyes. “He did the cell phone thing where he dropped it on my back because I was getting calls and texts.”
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Reyes was the sole survivor in his classroom -- all 11 of his students were among the 21 killed in the massacre.
He said he's now aware of the video that shows officers standing by for more than an hour, before rushing the classroom and taking the gunman out.
"For them not to do anything, it's like, I mean, it's mind-blowing because they had a lot of time,” he said.
Among them was Uvalde ISD Police Chief Pete Arredondo, who is Reyes' cousin.
"I want to set the record straight. I don't blame him personally. It was a lot of agencies that, they should've acted fast,” said Reyes.