After every school shooting, the public wonders how no authority took notice of the behavior of the culprit prior to the shooting. Sadly in this story, authorities did identify a threat before a tragedy – and it didn’t help.

William Atchison knew exactly why the two FBI agents were at his door.

“Relating to my internet history or whatever?” he said as the duo entered his family’s modest home in a remote area of northwestern New Mexico on March 24, 2016.

The FBI’s visit was prompted by an alarming post Atchison had left on an internet message board weeks earlier, according to court records. Atchison, 21, said he was “plotting [a] mass shooting” and looking for “weapons that are good for killing a lot of people within a budget.”

But “I’m not the type to actually do any of this stuff,” Atchison told the agents, according to a recording of the interview obtained exclusively by NBC News. The FBI agents agreed, their report says, and they closed the case.

The next year, on Dec. 7, 2017, Atchison walked through an unlocked door at his former high school in Aztec, New Mexico, and used a legally purchased semi-automatic handgun to kill Casey Marquez, a cheerleader who coached gymnastics, and Francisco “Paco” Fernandez, a football player. Then he turned the weapon on himself as police closed in. It was one of 50 school shootings in 2017.

An NBC News examination of the Aztec High School shooting — including a review of government records and an audio recording of an FBI interview of the future shooter — found a series of missed opportunities that point to what some experts say are nationwide shortcomings in how authorities assess and respond to potentially violent domestic extremists.

The missed signals in the case echo what happened before the school shootings in Parkland, Florida, when the FBI failed to act on tips about the shooter, and in Oxford, Michigan, where school officials are accused of ignoring obvious warning signs.

“This is yet another example of system failure,” said James Densley, an expert in mass shootings who co-founded The Violence Project. “There’s no national unified standard that everybody follows in terms of how to conduct these threat assessments and how to join those dots together.”

In the months before the shooting, Atchison left a trail of racist hate and despair in publicly available online postings that authorities never saw, according to court records. On the day of the killings, he carried a thumb drive with a note that read: “If things go according to plan, today would be when I die. I go somewhere and gear up, then hold a class hostage … then blow my brains out.”

But there were plenty of warning signs authorities did see. The crucial missteps, according to court records, government reports and experts who reviewed the case for NBC News, included: 

  • School officials never notified police when Atchison was suspended in 2012 after he wrote a chronology of the shooting at Columbine High School in Colorado on a white board, an act experts called a telltale indicator of potential violence. 
  • The FBI didn’t inform the high school after it discovered the March 2016 posting in which Atchison threatened to carry out a shooting, then closed its investigation without following up after Atchison told agents he was fascinated with mass killers, had posted violent fantasies online and had once been suicidal.
  • After a miscommunication with the FBI, local police posted a “use caution” bulletin inside the station using the name and photo of Atchison’s older brother and never followed up to correct the mistake.
  • Because the FBI closed the case, the bureau failed to discover Atchison’s online relationship with an 18-year-old who shot and killed nine people in Munich, just four months after his interview with the agents. 

“There were many, many red flags,” said Jamie Lattin, whose daughter, Casey, was shot and killed. “There’s a lot to hold accountable from the school, Aztec Police Department, the FBI, the shooter himself, his family. Everybody’s at fault, all of them.”

Four years later, Lattin says she remains numb with grief.

“I know she’s gone. I know she’s not coming back. But I haven’t had to hit that wall yet, because I deal with her death every day — the circumstances leading up to her death, the people accountable for her death,” she said. “I still have a really long process in front of me. I had my kid for 17 years. Her death will never leave me.”

Neither the school district nor Aztec police would comment for this article, citing a wrongful death lawsuit by Lattin and her lawyer, Luis Robles. The FBI also declined to talk, even though a judge dismissed the family’s wrongful death claim against the bureau for technical reasons, ruling that the FBI was immune from being sued over its decision not to further investigate Atchison after the 2016 interview.

In a brief phone conversation, Atchison’s father, Wayne Atchison, said: “I place a lot of blame on the school system, because he was being bullied and they didn’t do anything about it. Instead, they condoned.” He wouldn’t elaborate.

Atchison had been out of school four years when he carried out the shooting. His father was with him when he legally purchased the murder weapon, a Glock handgun, at a sporting goods store on Nov. 3, 2017, according to a New Mexico State Police report.

‘I’ve had a screwed-up life’

It was around 3 in the afternoon on March 24, 2016, when the two FBI agents arrived, greeted by Atchison’s parents. It was two days before Atchison’s 20th birthday,

He quickly approached the agents, and before they could even get a question out, he began telling them about his online interaction with an infamous mass shooter.

“I’m not actually insane like these people are,” he said. “Like, let me just give you a briefing. So, like, around 2007, this dude, this guy, Pekka Auvinen, he was from Finland. He went psycho — He killed eight people. … there’s cults that actually worship these kinds of people. … I talked to him six times because I got to his channel through the Amazing Atheist …”

Atchison also told the FBI agents he had been repeatedly beaten and stabbed by bullies. “My body’s covered with scars from being stabbed,” he said. “My point is, I’ve had a screwed-up life.”

An agent interrupted him. “Let me make something really clear to you, William. It’s not against the law for you to be atheist. It’s not against the law for you to be anti anything. What is against the law is when you take it to a whole other extreme and posts are made and … or you act upon those anti feelings. You understand what I’m saying?”

Atchison replied: “Yeah. Like, obviously, I’m not the type to actually do any of this stuff.”

The agent said, “I guess my question for you is kind of what assurance can you give us?”

The future school shooter answered, “Well, you guys can f—-ing put me on a watch list and watch me and stuff.”

But there is no school shooter watch list. What the agents did, FBI records show, was close the case without further investigation. 

“Based on interviews conducted with the subject and subject’s family members, the [FBI] does not see a threat to the security of the United States,” their report concludes. “Additionally, the subject, although he claimed to have seen a psychologist in the past, does not have access to firearms, explosives or other destructive devices, and insisted the online posts were related to video games and/or the subject’s ‘trolling’ activities with the sole purpose of inciting controversy on the internet.”

The narrative concludes, ”As such, the [FBI] does not see an immediate threat to schools and/or the public in Aztec, N.M., or the surrounding areas.”

Indicators of violence

In a study of mass shooters, the group Everytown Research & Policy found that from 2009 to 2020, more than half of perpetrators exhibited at least one dangerous warning sign before the shootings, such as threats of violence. Combined, they took 596 lives and wounded 260 more people, the study found.

Atchison isn’t the only person who killed after having been the subject of an FBI interview and threat assessment. The FBI acknowledged it interviewed a man in 2020 who fatally shot eight people last year at a FedEx facility in Indianapolis. The bureau also famously interviewed Tamerlan Tsarnaev — and closed the case — two years before he orchestrated the 2013 Boston Marathon bombing.

But experts in mass shootings say they can’t recall such an FBI interview that was made public. They say the FBI’s hourlong exchange with Atchison paints a picture of a young man who exhibited a variety of indicators of violence.

“When I read this, it was like oh, my gosh, it’s so concerning,” said Jillian Peterson, a professor of criminology and criminal justice at Hamline University in Minnesota and a co-founder with Densley of The Violence Project.

Atchison talked to the agents about having been suicidal. He was fascinated with guns and mass shooters. He told FBI agents that he had been bullied and that he had engaged in his own bullying behavior online, lashing out with angry, racist, misogynistic, hate-filled rhetoric. 

“There are a ton of warning signs that we know from research are predictors of violence,” she said. “This was clearly a young man in need of some serious intervention.”

It’s not clear that any one agency, even the FBI, had enough information on its own to have successfully intervened to stop Atchison. The family argues that a collective failure to share information and connect the dots resulted in missed opportunities.

Robles, the Lattin family lawyer, summed it up this way: “The FBI failed to conduct the type of investigation that a federal law enforcement agency is expected to conduct. The school district knew that they had a potential threat, and they chose to ignore it. And the police department, when told about this potential threat, chose not to investigate it. And a tragedy resulted.”

San Juan County Sheriff Ken Christesen said after the shooting, “It’s a shame he wasn’t on our radar.”

Katherine Schweit, who ran the FBI’s active shooter program before she retired from the bureau, reviewed the tape and transcript of the FBI interview of Atchison for NBC News. She concluded that the FBI agents did a thorough job. She didn’t see anything that should have prompted them to open a criminal investigation.

“Even though he talked about a lot of different things and he talked about how proud he was of these shooters and those actions and this event … and how he posted admiring things about people who committed horrible atrocities, they are still just words,” she said.

“I hope you hear the frustration in my voice saying that, as a person who worked these cases … words are not violative — actions are.”

Peter Langman, who has spent a career studying mass shooters and has done consulting work for the FBI, agreed.

“Given the evidence at the time, I think they did a thorough investigation,” he said. “They could have pursued another couple avenues, but I don’t think that would have changed anything.”

He noted that the attack happened more than a year after the FBI interview.

“This is the challenge,” he said. “You can’t just keep monitoring every potential subject.”

‘If only I had’

Robles, who obtained the FBI case file through a Freedom of Information Act request, sees it differently. He argues that the online threat itself gave the FBI probable cause to obtain a search warrant for Atchison’s computer, which would have laid bare the extent of his violent extremism. 

“Because the FBI has taken it upon itself to investigate domestic terrorism, such as school shootings, they had a responsibility to conduct a thorough investigation,” Robles said. “The FBI didn’t do that. They didn’t go down the street and find out more about the school shooter from the school itself. And they would have been able to learn there was more to it. They did not execute a search warrant, obtain the computer that then could be used to charge him with a crime and essentially pull him out of society and protect society by doing so.”

Even if the FBI didn’t pursue its own criminal case, he said, the bureau should have passed along information about Atchison’s mass shooting threat to his former high school. The FBI did alert Aztec police, but the police department never interviewed Atchison, court records show.

If the FBI had accessed Atchison’s computer, Robles said, agents would have found ongoing discussions of violence between Atchison and a German man, David Sonboly, who later killed nine people and wounded 36 others in a shooting at a Munich McDonald’s in July 2016. 

German police uncovered the messages after the Munich shooting, said Florian Hartleb, a German scholar who wrote about the case in a book about so-called lone wolf violence.

“There are two dead children in Aztec, New Mexico, [and] nine dead Germans that essentially paid the ultimate price for the FBI not doing what they promised the American public they were going to do,” said Robles, who often represents police officers.

Schweit and other experts say the FBI gets thousands of tips every year about people who have said or done things suggesting they might commit violent acts. Most don’t lead to arrests — or violence.

“Thousands of times it doesn’t turn into anything,” Schweit said. “I have covered and worked on hundreds of shootings. Everybody says: ‘I should have done this. I should have talked to him. I should have. If only I had.’”

She added: “When I looked at the transcript and I see the comments that he posted online, they were not specific enough where I would have felt comfortable going to and getting a prosecutor to issue a search warrant. … You have to make sure that if you’re going to … invade somebody’s constitutional rights to freedom of association, to freedom of speech, you better have a very good idea that there’s some specific thing that somebody really means they’re going to do and it’s not just rhetoric.”

Peterson, the criminology professor, said the FBI and other authorities should have done more. The FBI agents asked Atchison whether he was willing to speak to a counselor, but there is no evidence in FBI records suggesting the bureau took any steps to facilitate that.

“The FBI probably should have been talking to local police, who should have been talking to the school,” Peterson said. “I would want those FBI agents to recognize that this was a kid in a very serious mental health crisis who probably was a danger to himself or others, who needed be connected to mental health services. … I would have hoped at a minimum for some sort of follow-up and some sort of further information gathering.”

That was a collective failure, said Lattin, Casey’s mother.

“I’ve said from the very beginning that this community needs to realize we lost three children that day,” she said. “He was raised by the same community mine was. He sat in the same classrooms. He had a lot of the same teachers. He had a lot of the same administration. This whole community lost him.”