New revelations from the Senate hearing have put an additional spotlight on Pete Arredondo, the embattled school district police chief who was the on-site commander during the Uvalde shooting but has largely remained silent in the wake of the mass shooting.

Arredondo has spent the day in the neighboring House chamber, testifying behind closed doors. A lawmaker on the state Senate panel called on Arredondo to appear before their committee in a public setting.

"I challenge this chief to come testify in public as to what happened here," said Sen. Paul Bettencourt, a Republican on the state Senate committee. "Don't go hide in the House and talk privately -- come to the Senate, where the public … can ask these questions."

"Not a single responding officer ever hesitated, even for a moment, to put themselves at risk to save the children," Arredondo told The Texas Tribune on June 9. "We responded to the information that we had and had to adjust to whatever we faced. Our objective was to save as many lives as we could, and the extraction of the students from the classrooms by all that were involved saved over 500 of our Uvalde students and teachers before we gained access to the shooter and eliminated the threat."

Texas Director of Public Safety Steven McCraw alluded on multiple occasions to specific lapses in protocol and training during the Uvalde shooting -- but his overall message is that police officials on site were not trained well enough.

"Obviously, not enough training was done in this situation, plain and simple. Because terrible decisions were made by the on-site commander,” McCraw said.

Asked what one recommendation he would make to prevent a repeat of Uvalde, McCraw was unequivocal: "We need to train more men."

He also suggested that the police failures at Robb Elementary could pose lasting harm to law enforcement's reputation.

"Mistakes were made. It should have never happened that way. And we can't allow that ever to happen in our profession," he said. "This set our profession back a decade, is what it did."

Texas Director of Public Safety Steven McCraw sought to clarify some confusion over whether the exterior and interior doors used by the Uvalde gunman to enter Robb Elementary School were locked -- and whether officers even needed keys to breach the classroom where the gunman had barricaded himself.

According to McCraw, the door to the classroom containing the gunman could not be locked from inside, meaning it was likely unlocked for the duration of the shooting.

"I have great reasons to believe [the door] was never secured," he said.

McCraw later said it appears that officers on the scene never checked whether the door to the classroom was unlocked, even as they waited for additional equipment to breach it and worked to secure a set of keys.

"How about trying the door and seeing if it's locked?" McCraw said he would ask the officers who responded first.

Regarding the gunman's entry into the building, McCraw confirmed previous reporting that a teacher at one point propped a door open but later closed it before the gunman arrived. He did not clarify how or why the door closed but remained unlocked.

"The only way you can lock these exterior doors in the West building ... the only way to do that is from the outside. You can't do it otherwise," McCraw said. "So when [the teacher] knocked the rock out, it closed securely, but there's no way for her to tell that the door was unlocked. The only way to know that the door is unlocked is to go out, close the door, OK, then try it."

Texas Director of Public Safety Steven McCraw laid out a series of communications failures that exacerbated the decision-making missteps that hampered the police response to the shooting at Robb Elementary School.

McCraw confirmed previous reporting that Pete Arredondo, the on-scene commander, arrived at the school without a radio. Later, according to McCraw, local police and Border Patrol lost radio communication signals inside the school.

Those circumstances ultimately led Arredondo and others to begin communicating with dispatchers on their cellphones, McCraw said.

"Cellphones did work, obviously, inside the school," he said. "It’s just the portable radio devices that first responders had didn’t."

McCraw also said "there was no duress system throughout the campus," which caused confusion among those inside the building. The principal of the school did trigger an emergency alert system called Raptor, but the program did not appear to sufficiently inform those inside the school about the shooting.

"It’s not the same as a direct system," he said.