As America emerged from the pandemic, communities continued to experience a rising tide of gun violence. School shootings and the rate of children and teens killed by gunfire both reached all-time highs since at least 1999. ProPublica’s coverage of gun violence reveals how first responders, policymakers and those directly affected are coping with the bloodshed.

In the end, it took 699 days to account for what went wrong before, during and after a deadly shooting at Oxford High School in Michigan.

Nearly two years after the shooting, which killed four students and injured seven others, an outside consulting firm that conducted an independent investigation issued a sweeping report that faulted top administrators and other school officials for “failure and responsibility by omission.”

The 572-page report from Guidepost Solutions, a New York-based firm that specializes in investigations, compliance and security, said that had threat assessment and suicide intervention been carried out appropriately, the November 2021 shooting could have been prevented.

Guidepost also found missed opportunities in the aftermath of the shooting. The report describes efforts by the lawyers for Oxford Community Schools and the teachers union to discourage people from cooperating in the investigation, showing why it can be so difficult for communities to find transparency and accountability following a mass shooting.

Some school leaders encouraged staff to participate in interviews with the consultant, the report said, but the school board made it voluntary, rather than a condition of employment. The board didn’t even say it “expected” district employees to participate.

This “hindered our ability to conduct the investigation effectively,” the report said.

Of the 161 people Guidepost investigators asked to interview, 70 refused or did not respond, including most of the shooter’s former teachers and several critical witnesses to the shooting. Both employees who met with the shooter hours before the incident did not cooperate. Of those who were interviewed, some would not speak about threat assessment practices preceding the violence.

For the report, investigators also turned to police reports, surveillance video, social media posts, deposition transcripts and other records, including files from the county prosecutor’s ongoing criminal investigations.

In May, a ProPublica story described how comprehensive third-party reviews of school shootings are very rare — typically happening only after the highest-profile tragedies. Even then, haphazard approaches can breed mistrust and waste the chance to learn lessons on prevention.

Oxford Community Schools declined multiple offers from Michigan’s attorney general to investigate, the story said. For six months, Oxford’s board followed guidance from a lawyer retained by the school’s insurance company, SET SEG, as it insisted that it couldn’t launch a review until criminal and civil cases were resolved. But there was no such prohibition from prosecutors.

ProPublica’s story described how the delay in approving an independent review contributed to an atmosphere of mistrust among parents and community members.

The morning after the report’s release, Renee Upham, an Oxford mom who used to teach at the district’s middle school, wrote an email to school officials that she shared with ProPublica, calling on them to apologize to students, staff members and families. It also asked when key figures will be put on leave or terminated.

“The report is damning,” Upham wrote. “At its core, it shows failures going back years that could have prevented the murder of four children and the injuries, both physical and emotional, of others.”

After allowing “two years to pass before the truth came out,” she wrote, the district now has a chance to own it. “Please do so, she wrote. “That is what authentic leadership is.”

The report released Monday was the second from Guidepost. In May, the firm released a 179-page report that assessed Oxford’s current security, suicide intervention and threat assessment strategy. But the accountability report released Monday is the one many community members wanted most.

On Thursday, Guidepost will host three town hall meetings to answer questions from the community about the report.

“I cannot believe it has taken almost two years to get to this point,” wrote Danielle Krozek, an Oxford mom, in an email to two Guidepost leaders this month that she shared with ProPublica. She thanked them for their time and effort, but also said she felt “on edge and skeptical.”

“This community and administration have missed the opportunity to acknowledge devastating failures and set the example for our state and nation,” she wrote.

In an interview with ProPublica earlier this year, Dan D’Alessandro, then-president of the school board, acknowledged the community’s anxiety and mistrust over the long wait. “Sometimes the messaging that comes out from the legal system and the legal teams isn’t necessarily reflective of that of what the school district is trying to do,” he said.

During the Nov. 30, 2021, rampage, an Oxford sophomore killed Tate Myre, 16; Hana St. Juliana, 14; Madisyn Baldwin, 17; and Justin Shilling, 17. The shooter pleaded guilty to charges including murder and terrorism and faces the possibility of a life sentence without parole.

In an unprecedented case, prosecutors also charged the shooter’s parents with involuntary manslaughter, alleging they failed to respond to multiple red flags about their son. Four days before the shooting, his father bought a gun for him. The parents have pleaded not guilty.

At school, there were also a number of warning signs, including a disturbing drawing that pictured a gun and a bleeding body made in math class the morning of the shooting. It prompted a meeting with a school counselor, the dean of students, the teenager and his parents. Nobody in the family mentioned the gun, according to court records, and school officials didn’t ask about access to weapons.

Officials also didn’t insist the student leave school, alert senior administrators or call outside authorities, and they didn’t check the student’s backpack before returning it to him and writing him a pass back to class. The gun was in the backpack, along with ammunition and a journal where every page described shooting the school. Less than two hours after the meeting, he began firing at teachers and classmates.

“Missteps at each level throughout the District — from the Board, to the Superintendent, to the OHS administration, to staff — snowballed to create a situation where a student’s communications and conduct should have triggered a threat assessment and suicide intervention on November 30, but did not,” the report said. “None of these mistakes were intentional. But costly mistakes they were.”

The Oxford school district failed to put its written threat assessment policy into practice with instructions and guidelines, according to the Guidepost report. No senior administrators acknowledged having responsibility for implementing the policy.

Moreover, the district’s suicide intervention guidelines were out of date. Even so, existing school protocols should have led educators to send the troubled boy home, rather than let him return to class, according to the report.

The report also described “extraordinary acts of bravery and kindness” by district personnel, including administrators who tried desperately to save student lives during the shooting.

In the aftermath of the shooting, parents filed civil suits, alleging gross negligence against several school employees and arguing the district was liable for what happened. But strong governmental immunity protections are difficult to surmount. In May, a state circuit court judge dismissed public employees and institutions from all suits.

Federal suits alleging a “state-created danger” and naming the district and the two officials at the meeting with the teenager on the morning of the shooting are still being litigated.

In an earlier motion to dismiss, a lawyer, on behalf of the district, wrote that no one “can claim with a scintilla of support that the employees were not attempting to help this student.” The motion also argued: “With the benefit of hindsight, it is easy to suggest that more could have been done. However, that is not the legal standard.”

Shortly after the shooting, the Oxford school board voted for a third-party review to begin “immediately.” According to the board’s resolution, it should “look far beyond the criminal investigation and into all the systemic factors that were at play.”

When a review didn’t happen, community members challenged the explanation from the school board that such an investigation had to wait for legal reasons. Those parents eventually learned directly from the county prosecutor’s office that, in fact, an investigation would not interfere with criminal cases. The prosecutor’s office further indicated that it had made this clear to the school’s lawyers, and at least one parent forwarded the message directly to the school board.

Finally, in May 2022, Oxford hired Guidepost for the investigation. It was led by Bradley Dizik, an executive vice president who heads the company’s emerging issues and technology practice group, and Andrew O’Connell, president of investigations and private client protection.

But even then, Timothy Mullins, the lawyer retained for the school by the insurance company, and union officials cautioned against talking. The union has pointed out that some members did cooperate with the investigation.

Mullins, in an email to ProPublica earlier this year, said that “critical witnesses have all been interviewed by law enforcement officials. They have also been deposed — under oath — by victims’ attorneys. Their sworn testimony has been set forth in voluminous transcripts, which are available to all parties and were provided to Guidepost by my firm.”

Deposition transcripts were useful but insufficient for the investigation, according to the report. Investigators noted that lawyers had different goals than they did and asked different questions than they would. (The report said that anyone interviewed by Guidepost was welcome to have an attorney present.)

Former board members told ProPublica that they worried that if they didn’t heed the advice of the lawyer retained by SET SEG, the school’s insurer could rescind coverage. Given the concerns of the district and certain employees, the report suggested legislation that explicitly prevents insurers from denying coverage to public schools and their employees if they participate in independent investigations into school shootings.

Anticipating the report, Oxford’s superintendent and the current board president informed families this month that the district would increase mental health support on campuses following its release and noted that the publicly funded All for Oxford Resiliency Center, established for those affected by the shooting, would expand its hours. They also pointed families to Oxford’s recovery plan and support services from county partners.