Why Nearly All Mass Shooters Are Men

This week, a shooting attack at a grocery store in Boulder, Colo., left 10 people dead. Just days earlier, eight people were fatally shot in a rampage targeting spas in the Atlanta area.

As with almost every mass shooter in recorded U.S. history, both of the suspects in the recent attacks are men.

A staggering 98% of these crimes have been committed by men, according to The Violence Project, a nonpartisan research group that tracks U.S. mass shooting data dating back to 1966.

"Men just are generally more violent," said the group's president, Jillian Peterson, a forensic psychologist and professor of criminology and criminal justice at Hamline University. "There are many theories as to why that is."

As NPR has reported, researchers say that men, more than women, tend to externalize their problems and look for others to blame, which can translate into anger and violence. And when women do choose violence, guns are not typically their weapon of choice.

If men vastly outnumber women as mass shooters, those perpetrators are often a model for the next male shooters who "see themselves in them," Peterson said, a phenomenon she noted is particularly true in young, white men. Violence Project data show that white men are disproportionately responsible for mass shootings more than any other group.

"They study the perpetrators that came before them," she said. "Many school shooters study Columbine, for example; other university shooters study the Virginia Tech shooting. And they really are kind of using those previous shootings as a blueprint for their own."

The following excerpts have been edited for length and clarity.

Interview Highlights

On why mass shootings were largely nonexistent during the pandemic

During the pandemic, we saw this type of shooting fade away for a number of reasons. The most obvious reason is places just weren't open. We weren't gathering en masse, we didn't have public spaces like schools and workplaces for this to take place.

Second of all, these mass shootings really faded from the headlines. We weren't talking about them, we weren't thinking of them. And because of that, that social contagion aspect of mass shootings really faded away.

And then the third piece is we were all kind of collectively grieving. We were all collectively going through this trauma and suffering through this global pandemic. So it's possible that individuals didn't feel as personally aggrieved during the past year.

But at the same time, as a psychologist, I've been worried about all the risk factors that we know of for mass shootings that have been exacerbated in the pandemic. So, trauma, experiencing a mental health crisis, suicidality, time online and access to firearms have all increased.

On what needs to happen to prevent mass shootings in the future

There's no one answer to the policies that we need to have in place. We can kind of work our way backwards and say, these are individuals who are in crisis, who have very easy access to firearms. And are there simple things we can do like universal background checks or safe storage that prevent that ease of access?

But we can also go further back and talk about things like, how do we make sure everybody's trained in crisis intervention and suicide prevention? How do we build trauma-informed schools, and go even further back? I think there's a lot of things that we can do as a society and even as individuals to help disrupt that pathway to violence.

On encouraging signs that show future mass shootings can be prevented

I would say, in particular, the media coverage seems to have shifted. I'm not seeing as much of the perpetrator in the news cycle. I'm not seeing the perpetrator's name and face everywhere, which we know is what contributes to the social contagion.

I think we are having these conversations about gun policies that we could put in place — like red-flag laws, waiting periods — that might have prevented this type of shooting. I am hopeful that people are really done with this and really ready to make the changes that we need to make to prevent future victims.

Michael Radcliffe and Tinbete Ermyas produced and edited this interview for broadcast. [Copyright 2021 NPR]