One out of every 15 adults in the U.S. has been present at the scene of a mass shooting, researchers have revealed.
More alarming is that over 2 percent of that group — or over five million of the 258 million adults counted in the U.S. Census Bureau in 2020 — have been injured during one.
“These are really high numbers for this seemingly unique and small subset of gun violence,” David Pyrooz, a professor of sociology and criminologist at University of Colorado at Boulder, said in a statement.
The authors also found that younger generations of Americans were significantly more likely to have been exposed than previous generations were. Gen Zers, who were born after 1996 and are in their late to mid-twenties, were at greatest risk. More than half of respondents said the incident had occurred in the last decade, which Pyrooz said led “credence to the idea of a ‘mass shooting generation.’”
According to the National Gun Violence Archive, there were 505 mass shootings in the U.S. in 2024. That figure is down from 2023 when there were 659. Both figures are up significantly from 2014 - the first year the archive kept tally - when there 272 mass shootings.
The study - which was published in the journal JAMA Network Open and revealed Friday - surveyed 10,000 adults in January of last year, asking them if they had ever been “physically present on the scene of a mass shooting.”
While there is no single, agreed-upon definition of the term “mass shooting,” this study defined it as a gun-related crime where four or more people had been shot in a public space - similar to the one used by the Gun Violence Archive database.
Being physically present was defined as “in the immediate vicinity of where the shooting occurred at the time it occurred, such that bullets were fired in your direction, you could see the shooter, or you could hear the gunfire.”
While some respondents who said they were injured had been shot, they were also hit by shrapnel or trampled in the panic that followed.

How many people die in mass shootings every year depends on the definition used. With the Gun Violence Archive’s definition, and that used by study authors, 722 people died in these incidents in 2023.
There were nearly 47,000 gun deaths that year: the third-highest total on record, although it was down for the second consecutive year. In 2020, gun violence had surpassed car crashes as the No. 1 killer of children in the U.S.
Pyrooz said he was not surprised by the results of his survey, noting that the 2017 Las Vegas shooting had impacted hundreds more people than the 61 killed or 867 injured.
“That translates to about one out of every 11,000 Americans who were on the scene of that shooting alone,” said Pyrooz. “Continue that to other events that have occurred around the country and the numbers, unfortunately, add up.”

The shootings weren’t just at large events. They were in bars, restaurants, schools, shopping outlets and synagogues.
Black people and men were more likely to have witnessed a mass shooting, researchers found.
“This study confirms that mass shootings are not isolated tragedies, but rather a reality that reaches a substantial portion of the population, with profound physical and psychological consequences,” Pyrooz added. “They also highlight the need for interventions and support for the most affected groups.”
“It’s not a question of if one will occur in your community anymore, but when,” he said. “We need to have stronger systems in place to care for people in the aftermath of this tragic violence.”