The United States Secret Service’s National Threat Assessment Center (NTAC) released a report summarizing Mass Attacks in Public Spaces: 2016-2020. Contained in the report is an overview of 173 attacks that occurred across the U.S. over a five-year period. The incidents chosen for this report involved the harm of three or more people, not including the perpetrator. Most of these attacks were carried out by a single perpetrator.

This analysis intends to raise awareness among community organizations that have the means to aid in the prevention of mass violence. With 25 years of experience in behavioral threat assessment, NTAC asserts that mass attackers display warning signs of their intentions, and shares in this report some of these observable behaviors. For example, many attackers had a history of violence and were affiliated with the targeted locations of the attacks. Many attackers also used illegally obtained firearms and had a radical/political agenda.

The overview of attacks includes in-depth analyses of timing, locations, targeting/harm caused, resolution, motives, planning, weapons and additional items brought for the attacks. Analyses of the attackers involved in these incidents include demographics, employment, criminal behavior, substance use and abuse, mental health, belief systems, fixations, interest in violence/weapons, social isolation, bullying/harassment, stressors within five years, behavioral changes and other concerning behaviors.

NTAC concludes that strong community systems can prevent future tragedies by identifying and intervening when community members report their concerns.

For more information, check out HSDL’s In Focus topics on Active Shooters, Domestic Terrorism in the US, School Violence, and Workplace Violence.