A new study has revealed that about 7% of U.S. adults—roughly one in 15—have been present at the scene of a mass shooting at some point in their lives.
More than 2% have been injured during such events. The research, conducted by the University of Colorado Boulder, was published on March 7 in the journal JAMA Network Open.
The study also found that younger generations, especially Generation Z (those born after 1996), are at greater risk of being exposed to mass shootings compared to older generations.
This highlights the growing impact of gun violence on society and the urgent need for better support systems for those affected.
A growing public health concern
David Pyrooz, a professor of sociology and criminology at CU Boulder, led the study.
He hopes the findings will help close the knowledge gap on how mass shootings affect public health.
He also wants to encourage more programs that help reduce gun violence and support those suffering from trauma after witnessing such tragic events.
Pyrooz was deeply affected by the mass shooting at a King Soopers grocery store in Boulder on March 22, 2021, even though he wasn’t there. He remembers the sound of sirens that day and the impact it had on his community.
“It’s not a question of if one will occur in your community anymore, but when,” Pyrooz said. “We need stronger systems to help people recover from these tragedies.”
For the study, researchers surveyed 10,000 U.S. adults in January 2024. They specifically chose January since mass shootings tend to be less frequent during that month. Participants were asked:
“Have you personally ever been physically present at the scene of a mass shooting in your lifetime?”
Researchers defined a mass shooting as a gun-related crime in a public space where at least four people were shot. “Physically present” meant being close enough to see the shooter, hear the gunfire, or have bullets fired in their direction.
Nearly 7% of respondents said yes. More than 2% said they had been injured—not just from gunshots, but also from being hit by shrapnel, trampled while fleeing, or other injuries.
“One out of every 15 people in the U.S. has been at the scene of a mass shooting,” Pyrooz said. “These numbers are alarmingly high.”
The ripple effect
A single mass shooting can impact thousands of people. For example, during the 2017 Las Vegas Route 91 Harvest Music Festival shooting, 60 people were killed and 413 were shot. However, another 454 people were injured while trying to escape. In total, about 22,000 people were at the concert that night.
“That means one out of every 11,000 Americans was there,” Pyrooz explained. “When you add up incidents across the country, the number of affected people grows quickly.”
The ‘mass shooting generation’
The study found that younger generations are facing a reality their parents and grandparents did not. More than half of those who had been at a mass shooting said it happened in the last 10 years. This suggests that mass shootings are becoming a defining experience for younger adults.
“People who grew up after the Columbine school shooting are living in a different world than older generations,” Pyrooz said.
The study also found that Black Americans and men were more likely to have been present at a mass shooting. Surprisingly, income and education levels did not significantly affect the chances of witnessing or being injured in such an event.
The psychological impact
While this study did not measure the mental health effects of mass shootings, Pyrooz and his team are working on another paper that does. Early findings suggest that even those who were uninjured often struggle with lasting psychological distress.
About three-quarters of people who were at the scene of a mass shooting but weren’t physically harmed still reported symptoms like fear, anxiety, and depression. For comparison, only about 20% of the general population experiences these mental health issues.
This study serves as a reminder that mass shootings don’t just affect those directly injured or killed. Many more people are left dealing with the emotional and psychological consequences long after the event.
As mass shootings continue to rise, the need for better support systems and violence prevention programs has never been more urgent.
