What research says about identifying people who might commit mass shootings

Even if the proposed framework for gun safety legislation is signed into law, the U.S. will likely still struggle with far too many mass shootings. Researchers are trying to better understand what's behind these shootings. Dr. Jillian Peterson and Dr. James Densley, who co-founded The Violence Project, join William Brangham to discuss.

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  • Judy Woodruff:

    Even if the proposed framework that Lisa just described is signed into law, the U.S. will still struggle with far too many mass shootings.

    Researchers are trying to better understand what's behind these shootings.

    William Brangham picks up on that part of the story.

  • William Brangham:

    After mass shootings like those in Buffalo, Uvalde, Tulsa, and elsewhere, there are so many questions about the perpetrators.

    What was their motive? How did they obtain the gun? Were there warning signs? Could something have been done to avert these massacres?

    Two professors in Minnesota, Jillian Peterson and James Densley, set out years ago to answer some of those questions, with the hope of ultimately preventing the next tragedy.

    I spoke with them both earlier.

  • William Brangham:

    Jillian Peterson and James Densley, thank you both so much for being here.

    Jillian, to you first.

    Your research has focused on the characteristics that are shared by many of these mass shooters and some of the seeming striking commonalities between them. Can you explain a little bit about what you found?

    Dr. Jillian Peterson, Co-Founder and President, The Violence Project: Sure.

    So, we studied the life histories of 180 perpetrators who killed four or more people in a public setting. We built a database using publicly available data, and then also did about 50 interviews with perpetrators themselves and people who knew them, their victims, and first responders.

    And we identified this common pathway to violence that we saw over and over again. It often started with kind of serious violence in childhood, abuse, neglect. Different forms of trauma kind of laid the foundation. Then you see, over time, a build where they become isolated, depressed, hopeless.

    Oftentimes, this is a crisis that is kind of — they're actively suicidal or have attempted suicide previously .Then that self-hate kind of turned outward, and you see perpetrators finding who it is that they blame for how awful they feel. A lot of times, they study other mass shooters. They see themselves in these previous mass shooters. Or they're online and chat rooms or dark corners of the Internet getting radicalized towards violence.

    And these mass shootings are meant to be watched and witnessed. They kind of want their anger to go viral. They want their message to get out there. And they're also designed to be their final act. So, they go into it knowing they're not going to come out. And then, of course, they have access to the weapons that they need to do the shooting.

  • William Brangham:

    You mentioned before that many of these cases end up as suicides, and that there were not longer-term plans for the rest of the day or the day after. What does that help us learn?

    Dr. James Densley, Co-Founder and President, The Violence Project: I think that's a really, really important point and something which, for us doing this research, was a bit of an aha moment.

    Because, if you think about a mass shooting as being a final act, and that somebody who perpetrates this doesn't intend to ever get away with it, that's never why they go into this to begin with, many mass shooters are suicidal prior to the act. So they even have suicidal attempts in their histories, or they 100 percent intend to die in the act, and they write this in their diaries or manifestos and other things.

    It changes the way we think about prevention. What can we learn from suicide prevention techniques which would then apply to mass shooters? If mass shooters intend to die in the act, if they no longer care if they live or die, these are people who are in a really true crisis in their lives. What we learn from suicide prevention can be applied to get them out of that crisis to begin with, but also in how we talk about mass shootings.

    So, we have protocols in place in the media, for instance, that, when we talk about suicide, we often will offer resources. We will say, here's the telephone number for the national suicide prevention hot line. We won't dwell on certain details, because we're worried about copycats and contagion.

    Those same rules apply with mass shooters as well. Mass shooters are studying other mass shooters. So, if we can adhere by those same rules when we think about these events, that could also help stop the next mass shooting. And I think that's really what's the most important piece here.

  • William Brangham:

    Jillian, are there other parts of your research that — within these commonalities that you all found, that help us figure out how to prevent, how to identify, how to see these before they end up in the newspaper?

  • Dr. Jillian Peterson:

    Yes, so in identifying this pathway to violence, we thought about, how could you build off-ramps at different locations along this pathway?

    Because we haven't understood where these perpetrators are coming from, our typical response has been to try to minimize casualties once they occur, sadly. So we go through lockdown drills or we place armed guards, really, really kind of late-end stuff.

    But what we realized through this research is that mass shooters, they're not outsiders. They're not these kind of scary bad guys coming in. They're kids who go to that school. They're our classmates. They're our neighbors. They're our co-workers. In some ways, that makes prevention easier.

    I think it makes you — it requires a shift in thinking. But then it becomes noticing when people around you have a change in their behavior, and having systems in place where we can report that and it will be met with a response that's one of kind of care and concern and hooking you up to resources, rather than punishment or pushing you out.

  • William Brangham:

    Is it true that there are red flags, to use the term of art in this conversation, that there are signals that even laypeople can be aware of and to see clearly?

  • Dr. James Densley:

    Absolutely, there is.

    In fact, if you look at the numbers in our database, about half of the individuals that went on to perpetrate a mass shooting were communicating that intent to do harm in advance. And in the case of school shooters in particular, that number is actually about 80 percent.

    So it's very common for people to be telegraphing that violence is coming. They are often talking about it with friends and family, which is then dismissed as, ah, you know, this is just that casual conversation. Don't worry about it. They would never actually do it.

  • William Brangham:

    It's a disgruntled teen.

  • Dr. James Densley:

    Yes, exactly. Boys will be boys, that type of a mentality.

    Or they're posting things on social media, which perhaps just we are not putting those pieces of the puzzle together. And that's actually the most critical thing here is, time and time again, we see a very consistent pattern after these mass shootings, when we can go back and retrospectively look at them, which is to say that law enforcement knew something, a parent knew something, a teacher knew something, a classmate or a peer knew something.

    They'd spotted things on social media. They'd seen drawings, conversations, whatever it had been. But none of those individuals were necessarily talking to one another or sharing that information. And so it wasn't ever rising to the level where there would be an intervention.

    And that's usually the problem here, is that the systems are not necessarily in place or fully functioning to intervene at the crucial moment to prevent the tragedy from happening. So that's really then on us. The onus is on us now to build those systems, resource them, fund them, make sure people no longer fall through the cracks, so we can get ahead of this problem, and so we're not looking back on it and saying these were again missed opportunities.

  • William Brangham:

    Jillian Peterson and James Densley.

    The research and the book is called "The Violence Project: How to Stop a Mass Shooting Epidemic."

    Thank you both so much for your time.

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