Some do it out of a perverse desire to make a difference in the world. Others are driven by mental illness, pandemic isolation or social media influences that turn them into hateful and sadistic monsters.
But there's one increasing commonality among America’s mass shooters: their youth.
Robert “Bobby” Crimo, the man accused of firing on an Independence Day parade in Highland Park, Illinois, is 21.
Killers are a lot younger on average than they used to be, and researchers scramble to understand why in a desperate effort to stop the next one.
“They are trending younger. The 'why,' of course, is going to take a bit more research,” said Katherine Schweit, a former FBI agent who headed the bureau’s Active Shooter Resources until 2017. “But it appears that so many of them are crying out for attention – living through pandemic stress and getting indoctrinated online. And, you know, looking to be famous.”
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In past decades, most mass shooters in the USA were disgruntled employees who attacked their workplace or killed acquaintances or family members after they snapped from anger or stress.
A relatively new body of research indicates that one of the most pressing threats comes from angry young males who live with family and spend hours online with a community of others with shared grievances and an admiration for bloodshed.
Transitional teen years, pressures
Men in their late teens to mid-20s try to fit in with their peers as they find their place in the world. Often, they encounter rejection and alienation as they become independent of their parents and the social safety net.
Those pressures have been amplified over the past decade by internet and social media platforms where bullying and aggressive marketing of hateful ideologies – and weapons – are rampant, researchers and law enforcement officials told USA TODAY.
They said the problem was compounded by a mental health crisis that got exponentially worse during the pandemic-forced isolation.
“It's really proliferating,” said Arie Kruglanski, a psychology professor at the University of Maryland who has spent decades studying mass violence and extremism.
The anecdotal evidence of the rise of the young male mass shooter is overwhelming, he said, though few formal studies have officially quantified it.
Before 2000, there were about three mass shootings a year in the USA, Kruglanski said. In the first six months of 2022, he said, there have been more than 240. U.S. school shootings soared to about one a month in recent years, then escalated to the point where one occurs about once a week, he said.
USA TODAY defines a mass shooting as an incident in which at least four people are hit with gunfire, even if there are no fatalities.
Young mass shooters train their gunsights on targets other than schools, according to experts and law enforcement officials.
On Monday in Highland Park, police said, the gunman fired more than 70 shots from a rooftop, killing seven people and wounding nearly 40 with a legally purchased rifle before fleeing. The suspect was captured that evening after a manhunt.
Before the attack near Chicago, two 18-year-olds were accused of carrying out massacres in Buffalo, New York, and Uvalde, Texas. Both suspects followed a similar path, openly sharing menacing thoughts online and buying semi-automatic rifles as soon as it was legal.
In March 2021, a 21-year-old man was arrested after an attack that killed 10 people at a supermarket in Boulder, Colorado. Another 21-year-old was charged with gunning down shoppers at a Walmart in El Paso, Texas, in August 2019, killing 23 and injuring 23. A 19-year-old former student went back to Marjory Stoneman Douglas High School in Parkland, Florida, in February 2018 and killed 17 students and staff.
Younger, deadlier mass killers
Relatively few mass killings before 2000 were committed by men below the age of 21.
In 1999, two armed attackers, ages 18 and 17, roamed in trenchcoats through Columbine High School in Littleton, Colorado, and killed 13 people. In April 2007, a 23-year-old student gunman rampaged through the Virginia Tech campus, killing 32 people. In 2012, a 20-year-old killed 26 people, including 20 children, at Sandy Hook Elementary School in Newtown, Connecticut.
Soon after his 21st birthday, a white supremacist killed nine Black congregants of the Emanuel African Methodist Episcopal Church in Charleston, South Carolina, during Bible study in June 2015.
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It has been impossible to find common threads that explain the motivations behind mass shooters, especially the young ones, according to analysis by researchers and law enforcement agencies.
Some young mass shooters clearly suffered from mental illness, humiliation at the hands of school acquaintances or family or felt victimized in some other way. Several, including the Sandy Hook, Virginia Tech and Uvalde shooters, killed themselves after murdering so many others.
Others were motivated by racial hatred. The self-avowed neo-Nazi who attacked the church in Charleston confessed to committing his crimes in the hope of igniting a race war. Authorities described the act as domestic terrorism.
The El Paso gunman chose a Walmart in a heavily Hispanic area. The suspect had posted on the anonymous message board 8chan a 2,356-word "manifesto" containing anti-immigrant and racist rhetoric and a desire to divide the nation into territories by race.
The Violence Project, a nonprofit, nonpartisan U.S. research center dedicated to reducing violence in society, studied the problem in depth and found 175 variables in 180 mass shooting cases.
The organization found some commonalities, according to a comprehensive national database of mass shootings that it compiled with federal funding from the National Institute of Justice. More than 80% of mass shooters were in a noticeable crisis before the shooting, and many showed signs of increased agitation, the Project’s Mass Shooter Database found, according to data compiled from 1966 through 2019.
Many of them – like the Highland Park suspect, authorities said – were obsessed with violence, other mass shootings and a wide array of conspiracies.
Other shooters, according to the Violence Project data, exhibited symptoms that were much harder to categorize. Psychosis played no role for nearly 70% of mass shooters, it found, although many mass shooters experienced feelings of suicidality either before or during their attack.
Hate-motivated mass shootings and fame-seeking perpetrators, the project said, have rapidly increased since 2015.
A 'quest for significance'
Many mass shooters, especially young males in America, are driven by such an all-consuming desire to become recognized, or even famous, that it becomes a form of extremist radicalization, said Kruglanski, who directs the University of Maryland’s Motivated Cognition Laboratory. At the lab, his team uses experiments, neuroscience techniques, computer modeling and text analyses to study what causes violent extremism.
Kruglanski said the desire for fame and social worth is neither a sign of mental illness nor psychological pathology. It is something much more fundamental, he argued, stemming from the human quest for self-worth and the hunger for acknowledgment and respect.
“The quest for significance is the most important human motive, the most important social motive – to have dignity, to be somebody, to matter, to gain attention,” he said. “And unfortunately, violence is one way, a kind of primordial way, of doing that.
“This has been exacerbated by the fact that these shooters are gaining tremendous media attention, sometimes more than TV stars and film stars. And therefore they feel that doing it is a surefire way of gaining status and significance,” Kruglanski told USA TODAY.
This quest for social worth appears acutely in adolescence, he said, when the momentous life transition between childhood and adulthood is complicated by soaring hormones, turbulent emotions and gnawing uncertainty.
“The fact that they're getting younger just suggests that people of all ages are picking up on that idea that if you feel insignificant, if you feel frustrated, if you feel threatened or anxious about your place in the world, there is a way for you to becoming a superstar in the course of a few hours, by picking up a gun and shooting up people,” Kruglanski said.
Social media platforms that put a premium on popularity can reinforce that narrative.
The Buffalo mass shooter livestreamed his attack on social media, as did a gunman who murdered 51 people at two mosques in Christchurch, New Zealand, in 2019. Many recordings of it are available online.
Kruglanski described this online groupthink as a form of radicalization and extremism because the shooters, not unlike suicide bombers, disregard that their victims are innocent people, including children.
“All that is suppressed," he said. "It is forgotten at the time, where the only thing that counts is how to feed the quest for significance. And unfortunately, I think it's spreading."
An 'echo chamber' of violence
Brian Murphy, a former FBI and Department of Homeland Security official, blamed much of the spike in young U.S. male mass shooters on social media, including Facebook, Twitter and the ubiquitous TikTok videos devoured by those under the age of 25.
“We cannot underestimate the ways in which social media serves to reinforce beliefs, including extreme, violent ones,” said Murphy, who ran three investigative social media platforms for the FBI, then headed the social media intelligence branch of the DHS during his 26 years in law enforcement. Since retiring last September, he has run similar operations at the U.K.-based private firm Logically.
“This is not a new phenomenon, but the trend is accelerating, and the outcomes are more deadly,” said Murphy, whose company works with private and government clients to weed out online extremism. “Young men find, in a self-imposed, ever-shrinking online environment, an echo chamber of like-minded violent types who push out the people they do not agree with."
Among angry peers, a potential mass shooter's grievances are normalized and even encouraged. Most participants in this kind of feedback loop will never act out physically, but some, Murphy said, become so detached from reality that they become convinced that they alone "have found out what must be done.”
Often, “what must be done” to correct some perceived injustice, is going on a shooting rampage and gaining the credit for addressing it, Murphy told USA TODAY.
By the time they are moved to action, young mass shooters are often convinced they have nothing to lose, Murphy said, in part based on internet-driven narratives and groupthink.
“It is evident to me that unless something is done to change this trend line," he said, "it will only get worse.”
Schweit, the former FBI active-shooter coordinator, said she believes a different approach is needed, given how different the threat is from workplace attacks.
"The concern that I have, as a person who works in this field, is that we have more younger shooters, but we have less reporting by their peers and family members – and they are the only ones who are going to be able to help us kind of quell this increasing onslaught," said Schweit, who retired from the FBI five years ago to focus full-time on how to better educate American communities in identifying and stopping mass killers before they strike.
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'There's just too much out there'
One month after the Uvalde massacre, President Joe Biden signed the most significant gun control bill in nearly 30 years, enhancing background checks on gun buyers 18 to 21 years old. The bipartisan legislation encourages states to develop better "red flag" laws that would deny guns to people deemed to be dangerous.
Friends, family and online peers have to be willing to step forward and sound the alarm, Schweit said, because many young potential mass shooters are suicidal and reaching out for assistance even if they are not aware of it.
"They're crying out for help in a different way," she said. "But they have the ability to cry out for help and commit a mass murder."
The Highland Park suspect so alarmed his family with violent threats in 2019 that they alerted police when the boy “said he was going to kill everyone,” authorities said Tuesday. Police removed 16 knives, a dagger and a sword from their residence, but no criminal charges were filed.
Schweit, author of the 2021 book “Stop the Killing: How to End the Mass Shooting Crisis," said law enforcement, social media and internet companies must do better at catching – and flagging – the warning signs that precede a mass shooting.
But relying on them is a guarantee of failure, Schweit said.
“It's easy in an aggregate afterwards to say, 'He posted this on some website,' but the internet is as deep as the sand across the beaches of the world," she said. "It's impossible to monitor, even if there was a legal way to do it, which there isn't. There's just too much out there."
Making it more difficult, some mass shooters have posted threats and an intention to commit violence in private chatrooms or using encrypted apps.
Researchers and experts are working overtime to assess the data and get a handle on the problem, according to Schweit, Murphy, Kruglanski and others.
Follow or contact Josh Meyer on Twitter at @joshmeyerdc
This article originally appeared on USA TODAY: Mass shooters are getting younger and deadlier. Experts want answers.