Summary: A comprehensive analysis of mass murders in academic settings finds that the majority of perpetrators do not have severe mental illness. When psychosis is present, those attacks are more likely to use methods other than firearms. The study also confirms earlier observations: most mass school shooters are male and white, and nearly half of these incidents end with the attacker’s suicide.
Source: Columbia University
Researchers at Columbia University Irving Medical Center and the New York State Psychiatric Institute (NYSPI) analyzed 82 cases of mass murder that occurred at least in part on school, college, or university campuses worldwide and found that severe mental illness was absent in most perpetrators.
Led by Ragy R. Girgis, MD, and Gary Brucato, PhD, the team examined patterns across incidents to clarify how mass school shootings and related mass murders compare with other types of mass violence. Their analysis shows that firearms—particularly semi- or fully-automatic weapons—were the most common tools used in academic mass murders. In incidents without guns, stabbing was the most frequently reported method.
Published online Oct. 27 in the Journal of Forensic Sciences, this work draws on the Columbia Mass Murder Database (CMMD), the largest systematic review to date focused on mass killings in academic settings. The CMMD was built by the Center of Prevention and Evaluation (COPE) team after reviewing 14,785 murder cases reported in English between 1900 and 2019 to identify incidents involving multiple victims and to document perpetrators’ characteristics and methods.
Dr. Girgis, director of COPE, emphasizes that mass school shootings appear to be a distinct phenomenon with drivers beyond individual pathology. “To prevent future campus massacres, we must explore the broader cultural and social dynamics that contribute to these events—such as the glamorization of guns and violent imagery—rather than focusing narrowly on individual psychiatric diagnoses,” he said.
The research team categorized incidents by location (U.S. versus international) and by whether firearms were used. From the 82 academic mass murders they analyzed, key findings include:
– Nearly half of all incidents (47.6%) occurred in the United States, and a strong majority of firearm-related incidents (63.2%) were U.S.-based.
– Perpetrators in these cases were predominantly male (100%) and mostly white (66.7%), consistent with prior studies.
– Most perpetrators did not have documented severe mental illness (psychosis): 80.7% of firearm cases and 68.0% of nonfirearm cases lacked evidence of psychosis.
– When psychotic symptoms were present, the attacks were more often carried out using methods other than firearms.
– Almost half (45.6%) of the incidents ended in the perpetrator’s suicide.
Paul S. Appelbaum, MD, coauthor and Elizabeth K. Dollard Professor of Psychiatry, Medicine and Law at Columbia, warned that equating mass violence primarily with mental illness can mislead policy and deepen stigma for people living with severe psychiatric conditions. “These data suggest that focusing public attention on psychotic illness as the main explanation for mass school shootings is both inaccurate and potentially harmful,” he said.
The authors also note a notable prevalence of suicide among perpetrators. Nearly half of the attacks ended with the attacker taking their own life, which the researchers suggest may reflect a mindset in which the perpetrator views the violence as a final act. Understanding this motive could inform prevention strategies and law enforcement responses.
The study’s authors hope their findings will help policymakers, school administrators, and law enforcement better distinguish mass school shootings from other forms of mass murder, and to target interventions that address social and cultural influences—such as gun access, online communities that glorify mass violence, and media portrayals—rather than relying on individual-level psychiatric prediction, which the data do not support.
About this mental health and mass shooting research news
Author: Carla Cantor
Source: Columbia University
Contact: Carla Cantor – Columbia University
Image: The image is in the public domain
Original Research: Closed access.
“Mass murders involving firearms and other methods in school, college, and university settings: Findings from the Columbia Mass Murder Database” by Ragy R. Girgis et al. Journal of Forensic Sciences
Abstract
Mass murders involving firearms and other methods in school, college, and university settings: Findings from the Columbia Mass Murder Database
Mass killings at educational institutions—especially those involving firearms—are a pressing public concern, yet consistent patterns that could guide prevention remain hard to identify. While certain demographic features, such as male gender, recur across incidents, severe mental illness has not proven to be a reliable predictor.
Using the Columbia Mass Murder Database, the researchers identified 82 incidents occurring at least partly on school, college, or university property and classified each case by geography and whether firearms were used. Wherever possible, demographic and clinical differences between groups were evaluated statistically.
Findings show that nearly half of incidents were U.S.-based and that firearm-related academic mass murders were disproportionately located in the United States. Perpetrators were almost exclusively male and predominantly white. Most offenders had no documented history of psychosis, and psychotic symptoms were more frequently observed in cases that involved nonfirearm methods. Approximately 45.6% of incidents ended with the perpetrator’s suicide. These patterns suggest the need for prevention efforts that address broader social, cultural, and policy factors alongside targeted safety measures.