UVALDE, Texas -- According to a preliminary assessment of the Robb Elementary School shooting, state investigators believe the decision to delay police entry into the classroom was made in order to allow time for protective gear to arrive on scene, an official briefed on a closed-door presentation by the head of the Texas Department of Public Safety tells ABC News.
Waiting for protective gear contradicts active shooter protocols that have been adopted by law enforcement agencies across the country over the last 20 years.
Texas Department of Public Safety Director Col. Steven McCraw met Thursday with Texas lawmakers in a lengthy closed-door session at the state capitol in Austin, during which he briefed them on his agency's ongoing review of the massacre that left 19 students and two teachers dead.
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The DPS information is based, in part, on transcripts from 911 calls, dispatch audio, and body camera recordings, sources said. The review is ongoing and the DPS preliminary findings have not been made public.
A source confirmed to ABC News that the incident commander, Uvalde Consolidated Independent School District Police Chief Pete Arredondo, appeared to be aware that police needed to move faster as shots were being fired in two classrooms.
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"People are going to ask why we're taking so long," according to one of the transcripts, as relayed by the official to ABC News. The statement is believed by investigators to have been uttered by Arredondo during the 77-minute attack.
The New York Times first reported the quote and the details of the DPS information.
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Chief Arredondo arrived at Robb Elementary School without his radio, according to an official briefed on the investigation. Investigators still do not know whether or if he used a radio borrowed from one of the other officers on scene.
Investigators have also uncovered social media posts that suggested the shooter had been planning to acquire guns for the purposes of an attack and suggested he might not survive, the official said.
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