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Peter Langman researches the warning signs of school shooters

Peter Langman is psychologist who's studied school shootings since 1999.
Peter Langman is psychologist who's studied school shootings since 1999.

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Of course, just because the federal government isn't funding gun violence research, that doesn't mean NO ONE's doing it.

Take Peter Langman, for instance. He's a psychologist in Pennsylvania who's been studying shootings - specifically school shootings - for more than a decade. 

Langman has collected his research in a database at

On why he decided to vote so much time to this research

While I was doing my doctoral internship at a psychiatric hospital for adolescents and the attack at Columbine occurred. That was April 20th 1999. Then, just ten days later on April 30th, a 16-year-old boy was admitted to our facility because he was seen as a Columbine-type risk. I was assigned the case to evaluate him and he was the first of what became a very steady trickle of potential school shooters coming through the hospital. I thought, out of necessity, I needed to study these people.

On what he's learned by compiling all of this data into his website

There's a lot of things that have come out of this research. First of all [the potential shooters are] not all young... About half of them are 19 or older. They're actually adults not juveniles. There's no one profile, but they the tend to fall, psychologically speaking, into one of three different categories. So we're learning about them at a more nuanced level; not just as school shooters but are they psychopathic? Are they psychotic? Are they really traumatized individuals? We're trying to hone in on what are the factors that put them on the path to violence.

On the evolving demographics of school shooters

Based on my research, in the last 15 or so years, we're seeing more shooters who are middle-aged and we're also seeing a more diverse profile in terms of racial-ethnic identity. Up to Columbine for about 35 years ... most of the shooters were in fact white males as people often say. But since then ... we're seeing much higher number of non-white male shooters. So they're getting older and the demographics are also changing.

On the warning signs that he teaches others to be on the look out for

The warning signs really are based on the students behavior. And often in hindsight there've been very clear warning signs. I've talked to people about what's called "leakage;" when the [shooters] leak their intentions or inadvertently or deliberately. Are they engaged in what's called attack related behavior? Are they gathering firearms? Are they practicing with explosives? Are they trying to recruit people to join them in their attack? It's really looking at specific behavior that should trigger a deeper investigation.

To hear the full conversation, click the blue player above.