Ca. gun sales climbed following terrorist attacks, research shows

Handgun's are seen in a display case at Gary Kolander's shop Gun Vault in Mountain View, CA Wednesday July 25th, 2012. Handgun's are seen in a display case at Gary Kolander's shop Gun Vault in Mountain View, CA Wednesday July 25th, 2012. Photo: Michael Short / Special To The Chronicle 2012 Photo: Michael Short / Special To The Chronicle 2012 Image 1 of / 1 Caption Close Ca. gun sales climbed following terrorist attacks, research shows 1 / 1 Back to Gallery

Sales of handguns went up dramatically in California following the news of mass shootings in Newtown, Conn., and San Bernardino, a response researchers say could have been linked to fear on the buyers’ part.

And although there are no numbers for gun sales nationwide, residents in other states may have responded the same way, the researchers say.

A team of lawyers, doctors and statisticians say thousands more handguns than usual were sold in California within weeks of each of the two tragedies: the 2012 mass killings in Newtown, where a 20-year-old man gunned down 20 schoolchildren and six adults, and the 2015 shooting in San Bernardino, where a terrorist couple used semiautomatic weapons to kill 14 people at a holiday party.

Sales of handguns throughout California jumped 53 percent during the six weeks following the Connecticut mass murder, and rose 41 percent statewide after the San Bernardino attack, the researchers found. They also found that local handgun sales increased by 85 percent in the city of San Bernardino and its nearby suburbs after that episode.

About 48,500 handgun sales were expected in the six weeks after Newtown, based on previous sales numbers, the researchers said; instead, more than 74,000 handguns were sold. A total of about 67,000 handgun sales were expected after San Bernardino, and instead more than 94,000 handguns were sold, they said.

“Mass shootings are a unique form of violence that all people fear could happen to people like us, and each person fears ‘it could happento me,’” said researcher Garen J. Wintermute, an emergency medicine physician at UC Davis Medical Center who directs the center’s Violence Prevention Research Program.

David M. Studdert, a Stanford law professor and health policy specialist who led the research group, noted that nationwide details on gun sales are difficult to acquire because of recent federal laws, but all legal gun purchases in the U.S. do require federal background checks, and analyzing requests for those checks can give some indication of gun sale trends in other states.

“Unfortunately, with just one federal background check a person can buy five guns at a time,” Studdert said in an interview, “but we do see spikes in the numbers of people in every state who seek federal background checks after mass shootings.”

Studdert and Wintermute, along with their colleagues, used detailed records of California handgun sales maintained by the Department of Justice’s Bureau of Firearms. California is the only state where records of handgun purchases are publicly available, Wintermute said.

Their report was published Monday in the Annals of Internal Medicine.

“For some,” the authors wrote, “a gruesome mass shooting may induce repulsion at the idea of owning a weapon. For others it may motivate acquisition.”

David Perlman is the San Francisco Chronicle’s science editor. Email: dperlman@sfchronicle.com