Over a year after the school shooting at Robb Elementary School in Uvalde, Texas, the community still doesn’t know what went wrong. It’s a key reason we’re publishing findings based on a trove of raw materials investigators have yet to release.

When mass shootings devastate communities, investigators often set out to learn what happened by interviewing a wide array of people. What’s made public, if anything, rarely details the intimate, candid and emotional responses of the survivors and the first responders.

Today, ProPublica, The Texas Tribune and the PBS series FRONTLINE are jointly publishing an in-depth examination of the response to the mass shooting at Robb Elementary School in Uvalde, Texas, using a trove of raw materials from a state investigation whose findings have yet to be released.

The records include investigative interviews with officers, emergency responders, teachers and children, as well as video footage, audio recordings and photographs. Using these records, we reconstructed the day’s events, showing in painstaking detail how law enforcement’s lack of preparation contributed to delays in confronting the shooter on May 24, 2022. Nineteen children and two teachers died that day. Dozens of others will forever contend with scars, both physical and emotional.

Uvalde is one of at least 120 mass shootings since the 1999 Columbine High School massacre.

Experiences with other mass shootings have taught us that it can take years for communities to learn what occurred. In October, nearly two years after a shooting at Oxford High School in Michigan that killed four people, an independent consulting firm issued a report that found multiple failures. In other cases, such as the 2018 shooting at Santa Fe High School in Texas, where a gunman killed 10 people, families are still waiting.

Many in Uvalde have expressed frustration that they have not had access to more information about the shooting more than a year and a half later.

ProPublica and the Tribune are part of a coalition of news organizations that sued the Department of Public Safety, the agency investigating the law enforcement response, for records that it has declined to release. Last week, a state district judge ordered DPS to release records related to the shooting. The agency has said it plans to appeal the decision.

The journalism that ProPublica, the Tribune and FRONTLINE are publishing today will fill some of the void for those who want to better understand what happened and hopefully provide needed insights — and very likely raise important questions.

The process of putting together the documentary and investigative article involved significant work to understand the contents of the trove.

Reporters from the three news organizations reviewed hundreds of hours of body camera footage and investigative interviews, including more than 150 given by local, state and federal officers who responded to the shooting. They evaluated radio and dispatch communications and listened to the accounts of teachers, students and medics at the school that day. They also conducted separate interviews with teachers, students and parents, some of whom are featured in the article and the film.

A key part of the analysis required putting body camera footage on a timeline to try to establish an accurate chronology of the response. In many instances, the burned-in timecode on the footage was inaccurate. So, the reporters and editors used the sources in the trove — real-time surveillance footage, 911 and radio call logs, and a DPS spreadsheet — as well as audio and visual cues within the footage — such as sounds of gunfire, simultaneous actions and words spoken, images of cellphones with the actual time on screen — to help align with the actual time. As a result, in some instances, the time stamps in the original body camera footage are blurred in the documentary and in video clips in the article to avoid confusion.

Reporters also examined training across the country, finding that state laws require more instruction to prepare students and teachers for mass shootings than they do for the officers expected to protect them.

They conducted two separate 50-state analyses to determine how much preparation each state’s laws require for children and teachers compared with law enforcement officers. They also filed public information requests with the Texas Commission on Law Enforcement for the individual training records of more than 160 state and local officers who responded to Robb Elementary that day. Reporters used information provided by the officers in their interviews and body camera footage to determine how many arrived before officers killed the shooter. The newsrooms shared findings of officers’ training with law enforcement agencies, allowing them to respond with any additional information not reflected in the records. Most did not.

The news organizations sent letters to officers named in the article, outlining findings and offering them the opportunity to respond. Officers featured in the film also received letters. None agreed to speak with the reporters on the record. Some have previously defended their actions, including former Uvalde school district police chief Pete Arredondo, who did so in a June 2022 interview with the Tribune and in testimony before a state legislative committee.

Any time a child is named or a photograph of a child is included, we have obtained consent from at least one parent as a courtesy. That’s the case with a photograph showing children’s faces before the shooting, audio of investigative interviews with students and a 911 call with one of the children. All of the children who are named or shown survived.

We are also publishing a short video that shows Khloie Torres on a bus after the shooting. Her hair and clothing have blood on them that is not her own, and she is crying as she talks with a state trooper. The video, which includes a content warning, is being published with parental consent. Though it is difficult to watch, we believe it shows the human consequences of this mass shooting, as well as Khloie’s efforts to get help for her classmates.

Separately, journalists contacted the families of victims not mentioned in the article or the film to notify them that we would publish video and audio as part of our reporting.

We understand that detailed accounts of the day, including audio and video recordings, can be emotionally challenging.

The aim was to present enough information to help the public more fully grasp what happened while protecting the privacy of the children and teachers as much as possible. We believe the story and documentary offer a deeper understanding of these tragic events.