Jillian Peterson and James Densley, founders of The Violence Project, have, for two years, been studying the life histories of mass shooters in the United States for a project funded by the National Institute of Justice, the research arm of the U.S. Department of Justice.
They’ve built a database dating back to 1966 of every mass shooter who shot and killed four or more people in a public place, and every shooting incident at schools, workplaces, and places of worship since 1999.
They’ve interviewed incarcerated perpetrators and their families, shooting survivors and first responders. They’ve read media and social media, manifestos, suicide notes, trial transcripts and medical records.
Their data reveals four commonalities among the perpetrators of nearly all the mass shootings they studied:
- The vast majority of mass shooters in their study experienced early childhood trauma and exposure to violence at a young age.
- Practically every mass shooter they studied had reached an identifiable crisis point in the weeks or months leading up to the shooting.
- Most of the shooters had studied the actions of other shooters and sought validation for their motives.
- The shooters all had the means to carry out their plans.
In their LA Times Op-Ed, We have studied every mass shooting since 1966. Here’s what we’ve learned about the shooters, they go on to discuss how their data is helping develop strategies to prevent future mass shootings.