Understanding the Roots of Mass Violence: Mary Moriarty in Conversation with Dr. James Densley

Mary Moriarty (photo by Sarah Whiting)

In the wake of the traumatic mass shooting at Annunciation Catholic School in Minneapolis — an event in her neighborhood —Hennepin County Attorney Mary Moriarty sought to understand. She produced her eighth podcast episode of We Don’t Have to Choose with James Densley, one of the nation’s leading experts on mass shootings, for a discussion about why these tragedies occur and how to stop them.

Densley, a criminologist and co-founder of The Violence Project, has spent years compiling detailed life histories of mass shooters in the United States. The Violence Project database — covering around 200 cases — aims to illuminate patterns behind an epidemic that feels senseless yet remains disturbingly predictable.

He pointed out that he first studied violence for his Ph.D. dissertation about gang violence in his home country, which involved knife fights. After moving to the U.S., where firearms are the weapon of choice, he discovered that since gun violence happens in so many ways here, it needs multifaceted solutions:

• Everyday community gun violence is “often perpetrated with illegally held firearms, and the dynamics on the streets are reciprocal shootings. It’s retaliatory.”
• Domestic homicide might be perpetrated with legally held firearms, involving intimate partners.
• Police-related violence involves firearms used against officers and by officers.
• The leading cause of death from firearms is suicide. “That again requires a different set of tools to address.”
• Mass shootings are “the most rare, but the most extreme.”

Densley noted: “One of the things we’re seeing more and more of is shootings that are escalated from an interpersonal conflict, that in a time gone by might have been a fist fight and now have escalated to a shooting. And even worse than that are now escalating not just to one shooting, but a situation where you have multiple shell casings on the ground, and somebody has sprayed bullets into a crowd.”

He said this requires urgency to resolve, because it affects so many families living with this type of violence on a regular basis. Shooters are being aided by tools you can buy online to turn a regular weapon into a kind of machine gun.

All of these issues need customized solutions, he indicated.

Beyond “Monsters”

Moriarty noted how quickly the public labels perpetrators as “monsters.” Densley’s book, The Violence Project: How to Stop a Mass Shooting Epidemic, opens with a chapter challenging that reflex. “What they have done is monstrous,” he says, “but calling them monsters explains nothing.” The label provides psychological distance and absolves communities of responsibility. “Madmen do mad things,” he notes, “and that circular logic keeps us stuck.”

Instead, Densley argues for recognizing the perpetrators’ humanity — before the act. “Every shooter was someone’s son, classmate, or neighbor,” he says. “If we can see them before they pull the trigger, perhaps they never will.”

Prevention, he stresses, begins with connection.

To date, Densley and his Violence Project team have studied the lives of 200 individuals who have killed four or more people in a public space. “Where they went to school, their parental involvement, the mental health, whether they played violent video games, how they got access to firearms, whether they used SSRI medications, antidepressants, for instance. All the questions that you hear in the aftermath of these shootings, we tried to interrogate them all basically.”

They interviewed perpetrators of mass shootings in prison, first responders, survivors, victims’ families, people who knew the perpetrators — teachers, social workers. We tried to get at this from a sort of 360-degree perspective, to really look at these lives in detail, and “not only why they did what they did, and how they did what they did, but what can we actually do to prevent the next one.”

The point being that we otherwise tend to have blinders on, missing the warning signs that allow tragedies to happen. “Let’s remove the [blocks] that prevent us from seeing what’s right there in front of us, so that we can intervene early,” Densley says.

It is not simply legislation, police intervention, or investments in a new infrastructure that will prevent violent crime — it is about having methods for all community members to report concerns that can lead to people getting the help they need early.

Densley and his research partner, psychologist Jillian Peterson, have developed a “pathway” model of mass shootings built around four interlocking elements: trauma, crisis, script, and opportunity.

1. Early Childhood Trauma: Many shooters experience severe abuse, neglect, or instability. While most trauma survivors never become violent, untreated trauma can create a fragile foundation for future despair.
2. Crisis of Self: Nearly every case involves an existential or suicidal crisis. “The mindset of a mass shooter is someone who no longer cares if they live or die,” Densley explains. Mass shootings are, in essence, “suicides turned outward.” Preventing them means restoring people’s will to live — through kindness, intervention, and purpose.
3. The Script: In an age of online radicalization, potential shooters don’t act in a vacuum. The internet provides both a community and a “how-to” guide. Densley describes a disturbing digital subculture where past shooters are idolized and ranked by kill counts. Forums and gore videos serve as initiation rites, numbing users and deepening their identification with previous killers. The Annunciation shooter’s journal, Moriarty notes, revealed direct engagement with these online worlds — studying videos, critiquing past perpetrators, and treating their acts as blueprints. They even analyzed school lockdown drills for tactical advantage. “We’ve literally scripted this,” Densley warns. “Children rehearse what to do in a shooting, and one in a million might think, ‘Maybe I’ll do this.’”
4. Opportunity: Finally, access to firearms transforms intent into action. Densley emphasizes that most mass shooters acquire their weapons legally. Many are young adults who once had easy access through careless adults. “Friends don’t let friends borrow guns,” he says bluntly. Minnesota’s red-flag law — allowing temporary removal of firearms from people in crisis — is one underused prevention tool.

Moriarty adds that her office created an Extreme Risk Protection Order (ERPO) coordinator and public toolkit to make such interventions easier. “It’s not a cure-all,” she admits, “but it saves lives.”

The Culture That Fuels It

Densley and Moriarty explore the “performative” nature of modern shootings. Many perpetrators seek recognition or infamy; media coverage and social algorithms can unwittingly reward that goal. “When we plaster their faces everywhere,” Densley says, “we give them what they wanted most: attention.” He advocates the No Notoriety movement, which withholds shooters’ names and focuses instead on victims and prevention.

He also points to how online recommendation systems feed despair: “If you’re in a dark place and you search dark content, the algorithm will keep you there.” Parents and educators, he says, must assume exposure and start honest conversations rather than punishment. “Ask with curiosity, not fear: What content have you seen that disturbed you? Who do you follow online?”

Moriarty recounts how the Annunciation shooter’s fixation began years earlier with a pop-up about a mass shooting while at school — proof, she says, that exposure can start innocently and spiral dangerously.

Both guests challenge the booming “school safety” industry. Metal detectors, AI scanners, and armed officers, Densley says, “don’t match the data.” Most school shooters are insiders who know the security systems. Some even seek “suicide by cop.” Deterrence fails when the perpetrator expects to die. “We’ve created a fortress mentality,” Densley says, “when what we need is community.”

He applauds Minnesota’s new Trauma-Informed Active Shooter Drill law, which bans hyper-realistic simulations and requires post-drill debriefings. “That’s how we change the script,” he says.

Restoring Hope

The conversation ends on a note of hope. “Mass shootings are not inevitable,” Densley insists. Prevention can happen at many levels: policy, institution, and individual. He calls for investments in belonging: after-school programs, mentoring, sports, faith communities, and any structures that replace isolation with connection.

Moriarty closes with a direct appeal: legislative action matters too. “We know these shooters favor assault-style rifles,” she says. “We can keep them out of dangerous hands through sensible laws.”

For Densley, the core message is simpler: “Public acts of violence start in private loneliness.” He says that countering that loneliness — online and off — is society’s best defense.

Resources

Find the podcast here.

Find the YouTube video of the conversation here.

To support our ongoing Violence Prevention series: