Texas school shooting response was 'wrong', says official

Police made the "wrong decision" by not storming a classroom in Robb Elementary School as a shooter killed nineteen children inside, the chief Texas safety official has said.

"If I thought it would help, I would apologise," Steven McCraw said during a heated press conference on Friday.

He said officers delayed entering the room because they did not believe it was still an "active shooter" situation.

But pupils inside made multiple calls begging for police to come.

Mr McCraw confirmed there was a 40-minute gap from the police unit's arrival to the moment they decided to storm the classroom where the shooter had barricaded himself.

The senior officer on the scene decided to wait until the school janitor arrived with the keys because they thought that either "no kids were at risk" by then or "no one was living anymore".

The delayed police response, combined with video footage showing frustrated parents being tackled and handcuffed by police while the shooter was still inside the school, has led to growing public anger and scrutiny of how the police managed the situation.

Mourners visit a memorial for the victims

The shooter crashed his car near the school at about 11:30 local time, Mr McCraw showed up and walked around the building firing "more than one hundred rounds" into classrooms as he looked to get inside.

An officer for the school district, who was not on campus at the time, drove at once to the scene following a 911 call but "drove right by the suspect who was hunkered down behind a vehicle", Mr McCraw said.

By 11:35, the assailant had entered the school through a door that was propped open earlier by a teacher and barricaded himself into a classroom.

Police officers followed him into the building minutes later but remained in the hallway.

Mr McCraw confirmed that as many as nineteen police officers had gathered outside the classroom, but they made no immediate effort to get inside.

It was not until 12:51 that a tactical unit entered the classroom and killed him - about 75 minutes after the attack began.

The commanding officer on the scene - the Uvalde school district's chief of police, who was not present at Friday's news conference - believed the situation was no longer one involving an "active shooter".

The description is at odds with the disclosure that at least four emergency 911 calls were made from within the school - some from children barricaded inside with the shooter - begging for police to come.

During the news conference on Friday, Texas chief safety official Steven McCraw recounted the emergency 911 calls students made from inside the school after the shooter entered.

12:03: A student called 911, named herself and whispered that she was in room 112 at the school.

12:10: She called back and advised there were multiple dead.

12:13: The same student called for a third time.

12:16: She rang 911 back and said there were eight to nine students alive.

12:19: A 911 call was made, by another person - in room 111. She hung up when another student told her to.

12:21: You could hear over the call that three shots were fired.

12:36: The first caller called back and was told to stay on the line and be incredibly quiet. She said the shooter shot the door.

12:43 and 12:47: She asked 911 to "please send the police now".

12:46: The student said she could hear the police next door.

12:50: Shots were fired and could be heard over the call.

12:51: It was very loud, sounds like officers were moving children out of the room. At that point, the first child that called was outside before the call cut off.

"With the benefit of hindsight where I'm sitting now, of course, it was not the right decision. It was the wrong decision. There is no excuse for that," said Mr McCraw.

Growing emotional amid a barrage of angry questions following the admission, he called the mistakes "tragic".

After the shooter was shot dead, police found as many as 1,657 rounds of ammunition and sixty magazines in his possession.

They later learned he had forewarned of some of his actions in private messages to a Facebook friend. It was earlier alleged he made the declarations - "I shot my grandmother" and "I'm going to shoot up a school" - as public posts on the platform.

Mr McCraw said the suspect had asked his sister to buy him a gun last September but "she flatly refused".

In private chat messages with four people on Instagram earlier this year, he discussed buying a gun and asked questions about it.

One user responded: "Are you going to shoot up a school or something?"

"No, and stop asking dumb questions and you will see," came the reply.