With every detail that emerges about the Robb Elementary massacre, the police response looks worse.

In the days after the shooting, the Uvalde, Texas, police offered conflicting accounts of what took place when officers entered the school building and why it took so long to stop the rampage. The police changed their story repeatedly. Amid the multiple agencies at the scene — the Uvalde Consolidated Independent School District Police, the Uvalde Police Department, the Department of Public Safety, and Border Patrol — it wasn’t clear to some officers involved who was in charge.

For the past four weeks, investigators watched body camera video, footage from the nearby funeral home, and school surveillance video, and listened to radio traffic and phone and dispatch recordings. Now they’re getting some answers about why communication between officers failed, why basic active shooter protocol was outright ignored, and why teachers and students weren’t rescued for 77 minutes.

The picture emerging is damning.

Steve McCraw, the director of the Texas Department of Public Safety, who has been leading Texas’s investigation of the police response, described it at a recent Texas Senate special hearing as “an abject failure, antithetical to everything we’ve learned over the last two decades since the Columbine massacre.”

Eric Gay/AP

Investigations by the Texas Rangers, the Justice Department, and the local district attorney’s office are also underway, which means that new information will likely be released and change an ever-evolving story. Some Uvalde officials are already casting doubt on McCraw’s account, claiming that he is trying to distance state troopers and the Texas Rangers from the bungled response.

Here’s what has been revealed so far about three key contributors to the deadly delay.

1) Police had enough resources to act but they delayed for more than an hour

Three minutes after the shooter entered the building, enough armed officers were on the scene to stop the shooter, said McCraw. The post-Columbine doctrine for how to stop active shooter situations is clear, he argued: Officers must stop the killing and stop the dying. “You can’t do the latter unless you do the former,” McCraw said. But officers did not act quickly enough.

“The only thing stopping a hallway of dedicated officers from entering rooms 111 and 112 was the on-scene commander, who decided to place the lives of officers before the lives of children,” McCraw said. “The officers had weapons; the children had none. The officers had body armor; the children had none. The officers had training; the subject had none.”

At 11:33 am, the shooter entered the building. Three minutes later, as many as 11 officers had entered, nine with rifles — enough to isolate, distract, and neutralize the shooter. Yet officers waited for radios, rifles, shields, a sniper, and a SWAT team that was never needed.

At 11:37, the shooter — now in a classroom — fired another 11 rounds. Some of the bullets went through the walls and grazed two approaching officers. The officers retreated.

At 11:40 am, Chief Pedro Arredondo of the Uvalde Consolidated School District Police called the Uvalde Police Department’s dispatch on his cellphone and requested more assistance and a radio. “We don’t have enough firepower right now, it’s all pistols and he has an AR-15,” he said.

2) There was a futile scramble for keys that McCraw said weren’t even needed

Immediately after the shooting, law enforcement officials said the shooter was able to enter Robb Elementary because a teacher had the door propped open with a rock. Video surveillance shows that wasn’t true: The teacher knocked the rock out of the doorway before the shooter got to the school. The door, which could only be locked from the outside, was unlocked. (Even if it had been locked, there were glass panels beside the door that could have provided access.)

The classroom doors could also only be locked from the outside with a key.

Eric Gay/AP

“I don’t believe based on the information we have right now that that door was ever secured. In fact, I have great reason to believe it wasn’t secured,” McCraw said, since the shooter, who didn’t have a key, could enter, exit, and then reenter the classroom, as investigators observed on video.

Before entering the classroom, officers waited for a sledgehammer and a hooligan, a tool used to force entry. Both tools were available. They waited for a master key, which was requested nearly 45 minutes after the shooter entered.

“We’re having a fucking problem getting into the room because it is locked,” Arredondo said at 12:42 pm. Then: “They gotta get that fucking door open, bro. They can’t get that door open. We need more keys or something.”

“How about trying the door and seeing if it’s unlocked? No one had. The breaching team had been led to believe that the door was locked,” McCraw said. Officers also could have banged on the windows of the classroom to distract the shooter as others breached the door.

It took officers 1 hour, 14 minutes, and 8 seconds to enter the classroom and kill the shooter.

3) Investigators identified an incident commander — who says he wasn’t in charge

Investigators have named at least one person who they think is to blame: Chief Pedro Arredondo, who led the Uvalde Consolidated Independent School District police force. It was his jurisdiction, he was the ranking senior official, and he was issuing commands and directing actions, McCraw said.

Eric Thayer/Getty Images

Arredondo’s lawyer told the Texas Tribune in an interview that Arredondo did not believe he was the incident commander; he assumed that some other official had taken control of the larger response and so he took on the role of a front-line responder. They also told the Tribune that he “did not issue any orders,” contradicting McCraw’s evidence. Further complicating the chain of command was that most of the portable radios that the officers carried did not function inside the school, causing miscommunication, delayed information sharing, and the spread of misleading intel. The radio chatter that did occur was “chaotic,” McCraw said. Additionally, the charts the police officers used to devise a plan were wrong.

A day after McCraw’s testimony, Hal Harrell, the Uvalde schools superintendent, announced that he decided to place Chief Arredondo on administrative leave. Family members of victims have grown increasingly angry about the slow police response and are calling for Arredondo’s firing.

“I don’t like singling out a person and shifting and saying he’s solely responsible, but at the end of the day, if you assume incident command, you are responsible,” McCraw said.

Officers did try to counter commands to stay back, and it’s the reason the shooter was finally killed at 12:50 pm. The Border Patrol agents who breached the classroom and shot the gunman ignored a directive that they heard in their earpieces not to advance, according to a New York Times investigation. About an hour before, a Department of Public Safety special agent questioned whether there were still children in the classroom, saying, “If there’s kids in there, we need to go in there.”

The failure was broader than one person. “This set our profession back a decade,” McCraw said. “I don’t care if you have on flip-flops and Bermuda shorts, you go in.”

Here’s the timeline as it stands now but it might keep changing as investigations deepen

• 11:28 am: The shooter, who didn’t have a driver’s license or know how to drive, crashes his vehicle into a ditch, in front of Robb Elementary and the nearby funeral home.
• 11:29: A teacher inside the school observes the crash and calls 911 to report that there is a man with a gun; the shooter shoots at two people who left the funeral home after the crash.
• 11:31: The shooter begins shooting at the school, firing 27 times into two classrooms as he approaches the building.
• 11:33: The shooter enters the west entrance of the school through an unlocked door. The school begins an active shooter lockdown. The shooter fires into classrooms 111 and 112 through the hallway. He enters and exits the classrooms, firing more than 100 rounds.
• 11:35: Three Uvalde police officers, with two rifles, enter the school building.
• 11:36: A total of 11 police officers are in the building: Uvalde PD officers and school district police officers, including Arredondo.
• 11:37: The shooter fires another 11 rounds. Some of the bullets go through the walls and graze two approaching officers. The officers retreat.

5 minutes have elapsed since the first police officers entered. The police get a crucial fact wrong, complicating the response.

• 11:40: The chief received a report from an unknown officer that the shooter was “contained in this office,” suggesting that the subject was barricaded or that a hostage situation — not an active shooter — was in process.
• Shortly after 11:40: Chief Arredondo calls the Uvalde police from his cellphone and provides an incident description, asking for a SWAT team and a radio and claiming to lack firepower.
• 11:40: The shooter fires one round.
• 11:41: Uvalde police report that they believe the shooter is barricaded in “one of the offices” and is still shooting. (This is more misinformation. He’s not barricaded in an office, since there is no office on the floor plan.)
• Dispatch asks if the classroom door is locked and the officer responds, “I’m not sure but we have a hooligan to break it.”
• 11:42: More officers continue to enter the school.
• 11:44: The shooter fires another round.

10 minutes have elapsed since the police entered Robb Elementary.

• 11:48: Uvalde Consolidated Independent School District Officer Ruben Ruiz enters the school and tells officers that his wife told him she had been shot. Ruben is physically detained and escorted off the scene while having his gun taken away, according to McCraw.
• 11:52: The first ballistic shield enters the school building. Uvalde Police Department officers show up and get told to help with crowd control.
• 11:54: A Department of Public Safety special agent enters the building and asks, “Are kids still in there?” An unknown officer responds, “It is unknown at this time.”

20 minutes have elapsed since the police entered Robb Elementary. Delays continue, even as more equipment arrives.

• 11:56 am: The DPS special agent says, “If there’s kids in there, we need to go in there.”
• 12:03 pm: Khloie Torres, a student inside room 112, calls 911. The second ballistic shield enters the building.
• 12:04: The third ballistic shield enters the building.

30 minutes have elapsed since police entered Robb Elementary.

• 12:11 pm: Arredondo requests a master key.
• 12:14: Arredondo instructs officers to have a sniper on the east roof of the school.

40 minutes have elapsed since police entered Robb Elementary. Police continue to say they’re struggling to get into the room.

• 12:16 pm: Arredondo says, “I just need a key.”
• 12:17: Arredondo says, “Tell them to fucking wait. No one comes in.”
• 12:20: The fourth ballistic shield enters the building.
• 12:21: The shooter fires four rounds.
• 12:21–12:33: Arredondo, on body camera audio, asks for a breaching tool and says, “If he starts shooting, we’re going to lose more kids.” He continues to say that he needs keys to get through the door and that the keys he already has aren’t working. “We’re ready to breach, but that door is locked,” he says. “I say we breach through those windows and shoot his fucking head off through the windows.”

An hour has passed since police entered Robb Elementary.

• 12:35 pm: A hooligan tool, used by firefighters to gain entry, is brought into the building.
• 12:41: Arredondo says, “Just so you understand, we think there are some injuries in there. And so you know what we did, we cleared off the rest of the building so we wouldn’t have any more besides what’s already in there, obviously.”
• 12:42: Arredondo says, “We have a fucking problem getting into the room because it is locked. He’s got an AR-15 and he’s shooting everywhere like crazy. So, he’s stopped.”
• 12:43: Arredondo says, “They gotta get that fucking door open, bro. They can’t get that door open. We need more keys or something.”

70 minutes have passed since police entered Robb Elementary.

• 12:46 pm: Arredondo says, “If y’all are ready to do it, you do it. But you should distract him out that window.”
• 12:47: A sledgehammer enters the building.
• 12:50: A stack of seven officers tries to enter the classroom. Only four are able to enter the classroom because the door closes and leaves the other three out. Five officers fire rounds at the shooter and kill him.