The U.S. Justice Department’s National Institute of Justice (NIJ) recently published an article detailing the NIJ-supported and publicly available Violence Project Database that identifies common traits of individuals who engaged in mass shootings between 1966 and 2019. The database relied exclusively on open-source material, such as social media and newspapers, to construct a greater understanding of who mass shooters are and what motivates them.
From 1966 to 2019, mass shootings in the U.S. markedly increased, over half occurred after 2000, and 20 percent occurred in the last five years of the study. Deaths from mass shootings have also significantly increased over the past decade. In the 1970s, on average eight people were killed a year during mass shootings. From 2010 to 2019, the average jumped to 51 people killed annually.
The study details 172 mass public shooters and outlines more than 150 psychosocial history traits, including the individuals’ mental health history, past trauma, interest in past shootings, and situational triggers. Analyzing past shooters psychosocial traits reveals many shared attributes among these individuals. Many past shooters over the past half century were commonly troubled by personal trauma before the shooting, they were almost always in a state of crisis at the time, and, in almost half the cases, leaked their plans before the attack. Many shooters were insiders of the institution they chose to target, such as an employee or student. Finally, except for young school shooters, almost all individuals used a legally obtained firearm.
“This study — one of the most extensive assessments of mass violence to date—reveals a deeply unsettling trend: more Americans are dying at the hands of mass shooters than at any point in recent history,” said Principal Deputy Assistant Attorney General Amy L. Solomon. “This analysis paints a portrait of shooters, giving us a better idea of who commits these crimes and helping us detect the warning signals for these appalling acts of violence.” Read more at the Department of Justice and access the database here.
