Key Findings
Our research reveals consistent patterns across mass shooters that point to opportunities for prevention. These findings are based on analysis of every U.S. mass shooting since 1966.
Who Are Mass Shooters?
98%
of mass shooters are male
64%
are white, though representation varies by location type
34
is the average age of a mass shooter
64%
obtained firearms legally
Warning Signs & Crisis
80%
were in a noticeable crisis prior to the shooting
66%
leaked their plans to others beforehand
68%
had a history of childhood trauma or abuse
70%
made suicidal statements or attempts before the shooting
Mental Health
62%
had a prior mental health diagnosis
50%
were seeing a mental health professional at some point
30%
had been hospitalized for psychiatric reasons
18%
had a psychotic disorder diagnosis
Motivations
35%
were motivated by interpersonal conflict
26%
had employment-related grievances
16%
were motivated by domestic or family issues
12%
were motivated by hate or ideology
What This Means for Prevention
Our research points to concrete opportunities for intervention and prevention.
Prevention is Possible
Most mass shooters exhibit warning signs before attacking. Behavioral threat assessment teams in schools and workplaces can identify and intervene with people showing concerning behaviors.
Crisis Intervention Matters
The majority of mass shooters were in crisis before their attacks. Expanding access to mental health care and crisis intervention services can prevent tragedies.
Leakage Creates Opportunity
Two-thirds of mass shooters tell someone about their plans. Teaching bystanders to recognize warning signs and report concerns can save lives.
Firearm Access Matters
Most shooters obtained their weapons legally. Extreme Risk Protection Orders and secure storage laws can reduce access for those in crisis.
Our Methodology
The Violence Prevention Project defines a mass shooting as an incident where four or more victims are killed with a firearm in a public place. Our database includes over 200 variables per case, compiled from court records, media reports, and other primary sources.