The story behind the data on mass murder in the United States

In this Thursday, March 1, 2018, photo a rack displaying various models of semi-automatic sporting rifles is shown at Duke’s Sport Shop in New Castle, Pa. AP Photo/Keith Srakocic

News coverage in the days following the mass shootings in El Paso, Texas, and Dayton, Ohio, relied upon a common source for context: The AP/USATODAY/Northeastern University Mass Killing database. That’s because it’s the most comprehensive, most up-to-date repository of information on U.S. mass killings, says James Alan Fox, who is a criminologist at Northeastern University and one of the nation’s leading researchers on mass murder.

James Alan Fox, the Lipman Family Professor of Criminology, Law, and Public Policy at Northeastern. Photo by Adam Glanzman/Northeastern University

It’s research by Fox, the Lipman Family Professor of Criminology, Law, and Public Policy at Northeastern, and his colleagues that underpins the database.

“There’s a lot of misinformation floating around when it comes to mass murder,” Fox says. “My hope is that this database will be a standard place where people can get the most valid information.”   

Currently, only journalists and researchers at Associated Press and USA Today have access to the database, but it will soon be available to the public as well, Fox says.

The database includes every mass murder—which Fox defines as an incident in which four or more people, excluding the killer, are killed within a span of 24 hours—from 2006 forward. Fox says it’s difficult to find comprehensive, reliable information prior to 2006.

Fox has been studying mass murder for decades, and more recently teamed up with The Associated Press and USA Today, both media organizations, to create this searchable database of mass murders in the U.S.

Fox hopes that the more frequently the AP/USATODAY/Northeastern database is utilized to contextualize news coverage of mass murders, the more informed our reaction to such events will be.

For example, cases in which someone kills at least four members of their own family represent about half of all the mass murders since 2006. And 22 percent of all mass murders are carried out with a weapon other than a gun, he says. 

“These kinds of cases just don’t get as much attention,” as public mass killings by a gunman, Fox says.  

“It’s important for journalism’s sake, and for legislation’s sake, that the statistics be accurate,” Fox says. “Legislation should be grounded in valid statistics, not flawed ones.” 

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