Uvalde teacher who lost all 11 children in his classroom says a student called out to Texas police for help, but they had already left

• A Uvalde teacher said he heard a student call out to police for help during the May 24 massacre.
• Police, however, did not respond, Arnulfo Reyes told Good Morning America.

A Uvalde, Texas, teacher whose 11 students were killed in his classroom during the May 24 mass shooting at Robb Elementary School said a student called out to Texas police for help, but the officers had retreated.

"One of the students from the next-door classroom was saying, 'Officer, we're in here, we're in here,'" Arnulfo Reyes told "Good Morning America" in an emotional interview that aired on Tuesday. "But they had already left."

Reyes, a fourth-grade teacher, was in room 111 at Robb Elementary when the gunman burst into the school and fatally shot 19 children and two adults.

The gunman first entered room 112, then moved into Reyes' classroom through a connecting door. Reyes said the gunman shot him twice and killed all 11 students in his classroom.

Law enforcement said last month that police officers were in the school by 11:35, shortly after the shooting began, and exchanged fire with the gunman.

At that point, Uvalde Consolidated Independent School District Police Chief Pete Arredondo told officers to fall back and retreat, an official who was at the scene told the New York Times last week.

Reyes told "Good Morning America" that he had heard the officers arrive at the school but said when a student in room 112 called out for help, police had already retreated.

He said, however, that the gunman heard the student call out for help, and he went back into room 112 and started shooting again.

Despite arriving at the school within minutes of the shooting, police waited for roughly an hour before confronting the gunman.

Reyes said he felt abandoned by police, who have come under criticism in the aftermath of the shooting as new details come to light about how both the massacre and investigation have unfolded.

"After everything, I get more angry because you have a bulletproof vest. I had nothing," Reyes told "Good Morning America" of the police. "You're supposed to protect and serve — there is no excuse for their actions, and I will never forgive them."