UA Research Reveals U.S. Has Disproportionate Amount of World’s Mass Shootings

  • August 27th, 2015

TUSCALOOSA, Ala. — A country’s civilian gun ownership rate is the strongest predictor of its rate of public mass shootings, a correlation that is reflected in the United States’ disproportionate percentage of public mass shootings relative to its population, according to new research at The University of Alabama.

The United States was the site of 31 percent of the world’s public mass shootings from 1966-2012, despite having only 5 percent of the world’s population, according to research by Dr. Adam Lankford, associate professor of criminal justice at UA. In that span, the U.S. had more public mass shooters (90) than the next two countries on the list, the Philippines (18) and Russia (15).

“Until now, everyone was simply speculating about the relationship between firearms and public mass shootings,” Lankford said. “My study provides empirical evidence of a positive association between the two.”

Lankford’s quantitative assessment of 171 countries relied on multiple sources, including active shooter reports from the New York Police Department and the FBI, along with multiple international sources. Lankford used data of public mass shootings that resulted in the deaths of four or more people and didn’t include data of homicides committed during domestic disputes, hostage situations or robberies.

According to the study, a combination of American exceptionalism, American gun culture and stressors are potential factors in explaining the commonality of public mass shooters in the U.S. But previous studies did not include statistics of offenders worldwide, a gap in research that has partly contributed to the assumption that mass shootings are an American problem, Lankford reported.

Lankford also found that public mass shooters in other countries were 3.6 times less likely to have used multiple weapons – typically multiple guns, but occasionally a gun plus another weapon or weapons – than those in the U.S., where more than half of shooters used at least two weapons.

“The United States, Yemen, Switzerland, Finland and Serbia are ranked as the Top 5 countries in firearms owned per capita, according to the 2007 Small Arms Survey, and my study found that all five are ranked in the Top 15 countries in public mass shooters per capita,” Lankford said. “That is not a coincidence.”

Lankford said the association between firearms rates and public mass shooters doesn’t eliminate other major variables, like mental illness.

Lankford also found that mass shooters in the U.S. killed fewer victims on average than other countries. He hypothesizes that U.S. law enforcement is better at responding to the site and are better trained to handle the scenario.

“You do see cases in other countries where the first responding officer is out-gunned, gets killed and the incident goes on for hours,” Lankford said. “You don’t see that in the United States, post-Columbine.”

Lankford recently presented his paper, “Mass Shooters, Firearms, and Social Strains: A Global Analysis of an Exceptionally American Problem,” in Chicago at the American Sociological Association’s annual meeting. The paper will be published in a criminological journal in the coming months.

The department of criminal justice is part of UA’s College of Arts and Sciences, the University’s largest division and the largest liberal arts college in the state. Students from the College have won numerous national awards including Rhodes Scholarships and Goldwater Scholarships.


Dr. Adam Lankford, 205/348-9901,


David Miller, UA media relations, 205/348-0825,

The University of Alabama, the state’s oldest and largest public institution of higher education, is a student-centered research university that draws the best and brightest to an academic community committed to providing a premier undergraduate and graduate education. UA is dedicated to achieving excellence in scholarship, collaboration and intellectual engagement; providing public outreach and service to the state of Alabama and the nation; and nurturing a campus environment that fosters collegiality, respect and inclusivity.