UVALDE, Texas — More than 600 days after the mass shooting at Robb Elementary School ripped open a small Texas town, the father of 10-year-old Amerie Jo Garza is still looking for accountability. 

“That’s what everybody wants, that’s what we all want,” said Alfred Garza III, who, along with other family members of the 19 children and two teachers who were killed in the deadliest school shooting in Texas history, privately met with U.S. Attorney General Merrick Garland on Wednesday. “We want people to be held accountable for what they didn't do that day. That's all that's left to do."

Garland met with the families to brief them on a report that will be released after a 1:30 p.m. Thursday news conference.

The next step in what has become an excruciating 19-month process where questions still outnumber answers begins Thursday afternoon when the Department of Justice releases its long-awaited critical incident review of  what happened on May 24, 2022, when an 18-year-old gunman opened fire on a fourth-grade class.

The inquiry follows several investigations into what Department of Public Safety Director Steve McCraw called an “abject failure” of local law enforcement.

Here’s a timeline of what the public has learned from those efforts so far.

July 12, 2022: Security camera footage reveals 77 minutes of inaction

Several weeks after the shooting, hallway footage from Robb Elementary obtained by the Austin American-Statesman, part of the USA TODAY Network, and news partner KVUE showed, contrary to officials' and Governor Greg Abbott's statements on the day following the shooting, many police failed to show "heroism" in their response to the gunman's entry into the school.

While terrified students called 911 and parents outside the school begged law enforcement to confront the shooter, heavily armed officers wearing protective gear waited more than an hour -- 77 minutes -- before taking action. Authorities have said they killed the gunman when they finally entered the classroom but have never provided proof to back up that statement.

July 17, 2022: Texas House report cites 'systemic failure'

The following week, a special Texas House investigative committee released the first in-depth report on the Uvalde shooting.

The 77-page document contended that "systemic failures and egregious poor decision making" from both school personnel, who allowed a "regrettable culture of noncompliance" with safety rules, and police contributed to the deadly outcome. It also issued a scathing condemnation of the law enforcement agencies that responded on May 24.

"(Law officers) failed to prioritize saving the lives of innocent victims over their own safety," the report said.

The Uvalde school board later fired school police Chief Pete Arredondo for his failure to direct officers' response. Several other officers were fired in following months.

Dec. 19, 2022: Senate report suggests legislation on school safety, mental health

In preparation for the 88th session of the Texas Legislature, a Senate panel issued a report listing 24 policy recommendations that could help avert another school shooting.

The report from the Special Committee on Protecting All Texans, made up of eight Republicans and three Democrats, suggested making “straw purchasing” of firearms - when a person buys a gun for someone legally barred from owning one - a state felony. It is illegal under federal law, but the committee worried the law was rarely enforced.

The bulk of the suggestions focused on increasing campus security, including by establishing boards that would check for school vulnerabilities, improving and expanding the school marshal program, upping security funding and giving schools more authority to discipline and evaluate behavioral threats from truant students.

Another significant chunk of the report concerned mental health. The special committee suggested the state increase access to in-person and telemedicine mental health services for students and commission a study on mental health resource needs, among other recommendations.

Still pending: Uvalde County District Attorney and DPS investigation into police force; City of Uvalde investigation

For months, victims' families, journalists and even Uvalde's city government have sought findings from the DPS investigation into the shooting. The Statesman is one of several newsrooms suing DPS for access to the file.

But DPS and Uvalde County District Attorney Christina Mitchell, who said she saw initial findings in January 2023 and received the full DPS file in July, have kept the records under wraps to all members of the public except for some Texas legislators, who were shown some of the report on the condition that they sign nondisclosure agreements.

The Texas Department of Public Safety has said it is legally withholding information from public release at Mitchell's request, citing an ongoing investigation that could result in charges against the officers. Mitchell said she would present her findings to a grand jury before the end of 2023, but said her office would need more time in comments to the Associated Press in December.

In another ongoing investigation, the City of Uvalde hired an outside consultant, former Austin police detective Jesse Prado, to produce a report on the actions of its municipal officers. 

Thursday: The DOJ's roughly 500-page analysis of what went wrong

Several victims' family members told reporters Wednesday night after their briefing from Garland the DOJ report goes over the day of the shooting and they are hopeful that the outside analysis can provide fresh perspective, and spur action.

"I hope that people open their eyes and they do things that they should have done a long time ago,” he said.

But, he added, “I’m at peace with my loss. And I think that’s more significant than even the accountability part."

Contributing: Tony Plohetski, Austin American-Statesman