'It was clearly the wrong decision': Top Texas cop breaks down as he reveals 19 officers stood outside classroom where gunman trapped victims doing NOTHING because Uvalde police chief thought everyone was dead despite kids continuing to call 911

• e-mail

Texas' Director of Public Safety broke down in tears as he admitted 19 cops stood outside the classroom where the gunman in Tuesday's shooting had his victims trapped and did nothing because they thought everyone inside was dead, despite ongoing 911 calls from inside from children begging for help. 

Col. Steven McCraw made the admission at a press conference on Friday where he said it was 'the wrong decision' and came as the result of the Chief of the Uvalde School District Police Department Pete Arredondo mistakenly believing all of the kids in the classroom had already been killed. 

Police say they thought that every shot the gunman fired after that was aimed at the door and designed to keep them at bay.

'The incident commander thought at that time there was no more children at risk. Obviously there were children that were at risk,' he said. 

It remains unconfirmed how many children died while those 19 cops stood outside the classroom door. McCraw also revealed at the press conference; 

• The gunman fired more than 100 rounds after at 11.33am within seconds of walking into the school 
• He had purchased 1,000 rounds of ammo in total and been talking about buying guns for months 
• In March, he asked his sister to help him buy a gun and she 'flatly refused' but it's unclear if he was reported 
• In May, he spoke about school shootings with friends on Instagram and on May 14 he wrote: '10 more days, you'll see'
• The shooter's final shots were fired at 12.21pm and it's unclear if those were at kids or at the door 
• Children who were trapped inside the classroom made seven 911 calls in the hour that they were trapped, begging for help
• There was no resource officer at the scene but one arrived within seconds of hearing the first 911 call. He however didn't see the gunman hiding between cars in the parking lot and drove right past him 
• The gunman was able to get into the school because a teacher had propped open a door  

Ramos entered the classroom and locked the door at 11.34am. In the first few minutes, he fired more than 100 shots inside classrooms 111 and 112. 

He carried on shooting 'sporadically' until 12.21pm, and it wasn't until 12.50pm that police eventually gained access to the classrooms with a key from the janitor.  

'With the benefit of hindsight, from where I am sitting now - of course it was not the right decision. It was the wrong decision. There is no excuse,' McCraw said. 

Scroll down for video 

Heartbreaking new photos show kids running out of Robb Elementary School on Tuesday after the gunman opened fire. It's unclear what time these gut wrenching images were taken. They show cops pulling children through windows

U.S. Border Patrol agents rush Robb Elementary school children to safety moments after they were freed from inside a classroom via the window

Terrified kids run out of the school in Texas on Tuesday morning as a shooter terrorized a fourth grade class 

Cops and border patrol agents are shown looking for kids in other classrooms during the shooting on Tuesday 

Terrified kids run to safety after being rescued through windows from Tuesday's school shooting in Uvalde, Texas

Col. Steven McCraw cried as he admitted it was the 'clearly the wrong decision'. Police still do not know whether the shooter's victims were killed before or after police arrived at the scene

He latter sobbed as he said he and other police officers 'take an oath to protect people' but failed. 

'We want to know why this happened and know if we can do better next time,' he said. 

Uvalde Consolidated Independent School District Chief Pete Arredondo was in charge and mistakenly thought there were no other kids alive in the room once the shooter had barricaded himself inside 

Arredondo, whose decision it was not to advance because he thought all of the kids had died, was not at the press conference to answer questions and it remains unconfirmed if he was even inside the school at the time of the shooting. 

There was no school resource officer there when the shooter opened fire, contrary to previous reports from the police that he engaged in a shootout with the gunman. 

Instead, a school resource officer who was nearby and heard the first 911 call about the gunman crashing his truck rushed to the scene. 

They however drove directly past the gunman when he hid between cars in the parking lot. 

Instead, the school resource officer went to the back of the building and confronted a male teacher, mistaking him for the gunman. 

In the meantime, Salvador Ramos started advancing on the school, firing at classrooms. 

He then walked through an unlocked front door which was propped open by a teacher who had gone to retrieve their phone a minute before he arrived. 

While those officers stood inside waiting and he was shooting, parents were being put in handcuffs outside and held back from entering the school. 

The police response is now under investigation. 

Earlier, Department of Safety Lt. Chris Olivarez made the astonishing comments during an appearance on CNN last night. 

The shooter's abandoned AR-15 next to his pick-up truck. He bought the gun two days after his 18th birthday 

The gunman crashed his truck into a ditch before he entered the school on Tuesday morning  

He was being challenged by Wolf Blitzer over why the first officers who responded to the shooting retreated after Salvador Ramos shot at them with his AR-15 and then waited an hour for tactical SWAT teams to take him out, leaving him alone in a classroom with the 19 fourth graders and two teachers who he slaughtered. 

'Don’t current best practices, Lieutenant, call for officers to disable a shooter as quickly as possible, regardless of how many officers are actually on site?' Blitzer asked. 

He replied: 'In the active shooter situation, you want to stop the killing, you want to preserve life. But also one thing that, of course, the American people need to understand is that officers are making entry into this building. They do not know where the gunman is. They are hearing gunshots. They are receiving gunshots.'

He then appeared to try to take credit for the gunman being locked in the classroom with the kids for an hour - including some he shot at the start of the rampage who later died in the hospital - claiming it saved other lives. 

Police initially said that the gunman barricaded himself inside the classroom and that they had trouble gaining access to the room, and one unnamed law official anonymously spoke out to say SWAT teams had to wait for a different school staff member to bring them a key to the class. 

'At that point, if they proceeded any further not knowing where the suspect was at, they could’ve been shot, they could've been killed, and at that point that gunman would have had an opportunity to kill other people inside that school.

'So they were able to contain that gunman inside that classroom so that he was not able to go to any other portions of the school to commit any other killings,' Lt. Olivarez said. 

Scores of Border Patrol agents also rushed to the scene after hearing the incident unfold on scanners. When they arrived, the Uvalde Police Department also told them not to go inside, according to a law enforcement official who spoke anonymously to The New York Times. 

Eventually, the agents joined parents and a handful of local police officers in pulling kids through windows from other classrooms. 

The agents did not understand why they were being told not to go inside when the gunman was still in the building. 

Experts have slammed the decision to wait for back up as 'outdated' and 'disgusting'. 

'Waiting an hour is disgusting. If that turns out to be true, then it is a disgusting fact,' Sean Burke, a retired school resource officer from Massachusetts who now is the president of the School Safety Advocacy Council, told NBC. 

'If you’ve got somebody you think is actively engaged in harming people or attempting to harm people, your obligation as a police officer is to immediately stop that person and neutralize that threat. 

'We don’t expect police officers to commit suicide in doing it. 

'But the expectation is that if someone is about to harm someone, especially children, you’ve got to take immediate action to make that stop,' Don Alwes, an ex-instructor for the National Tactical Officers Association, added. 

Surgeons at the hospital in Uvalde have also suggested that the delay in responding to the shooting may have cost some kids their lives. 

It remains unclear exactly how many children were in the classroom when the shooter opened fire, how many were killed immediately and how many were still alive but injured when police arrived. 

Uvalde Memorial Hospital received two kids who had died by the time they got to the hospital.

Now, doctors are highlighting the importance of treating gunshot wounds as soon as they happen. 

'You can't wait until patients go to a trauma center. 

US Border Patrol agents were among the hundreds who responded to the shooting but when they got there, the local police department told them not to advance

This is how the shooting played out over the course of nearly two hours from when Ramos killed his grandmother at home. He arrived at the school at 11.28am and the first 911 calls were made. He then walked unobstructed into the building with his AR-15 and headed towards the classroom. He fought off cops at 11.44am, then was left alone in the room with the victims until around 12.44pm - when SWAT arrived. The incident was declared over at 1.06pm 

'You have to act quickly,' Dr. Ronald Stewart, the senior trauma surgeon at the University Hospital in Antonio, said. 

He added that uncontrolled bleeding was the top cause of deaths among gun shot wound victims and that it can happen in as little as five minutes. 

Since the Columbine shooting in 1999, officers across the nation have been advised not to wait for backup and to proceed into the school to find the shooter. 

Instructions from the Texas Police Chiefs Association says: 'The first two to five responding officers should form a single team and enter the structure.' 

Why that advice was ignored in Uvalde is among the many aspects of the slow response that are now under investigation. 

Another is why police falsely claimed at first that the shooter exchanged gunfire with a school resource officer before he even made it to the classroom. 

On Thursday night, Olivarez  said that was the information police received. 

Video shows Texas cops holding down a parent outside Robb Elementary School on Tuesday while a shooting unfolded inside

The girl explained she wasn't hurt and the blood was from her best friend 'Amerie.' It was then that Angel Garza (above) realized the blood he was looking at came from his own daughter

'So that’s information that we received early on in this investigation. 

'The Texas Rangers are now conducting interviews with those officers trying to establish exactly what was their role, and that will help us establish a more factual, concrete timeline,' he said. 

There is growing anger and frustrating among parents who were pepper sprayed, pinned to the ground and even placed in handcuffs.

'The police were doing nothing,' Angeli Rose Gomez told the Wall Street Journal. 

'They were just standing outside the fence. They weren't going in there or running anywhere.'

Gomez has two children in second and third grade and she reportedly drove 40 miles to the school after hearing of the attack.

She was one of the desperate parents who encouraged police with increasing urgency to enter the school. 

Eventually, federal marshals put Gomez in handcuffs and told her she was under arrest for intervening in an active investigation, the Wall Street Journal reported.

Gomez said she was able to convince a Uvalde officer whom she knew to have the marshal free her and she took the opportunity to move away from the crowd, jump the school fence, and ran inside the school where she rescued her children herself.

She said that other parents also trying to get to their kids were tackled and even pepper-sprayed by police. 

Angel Garza, whose daughter was killed, was handcuffed after trying to run into the school when he heard that a 'girl called Amerie' had been shot. 

Garza later told his heartbreaking story to Anderson Cooper. 

He explained that when he arrived on the scene he tried to help a young girl covered in blood, because he is a trained medic. 

The girl explained she wasn't hurt and the blood was from her best friend 'Amerie.'

It was then that Angel realized the blood he was looking at came from his own daughter. He later found out that she was among those who died.