https://www.sciencedaily.com/releases/2019/08/190826092332.htm

The UC Davis School of Medicine study, will be published August 25 in Injury Epidemiology, assessed the sharp rise in handgun purchasing across 499 California cities and estimated whether the additional handguns increased fatal and non-fatal injuries in these communities. It is the first study to use a direct measure of handgun purchasing to link firearm purchases with subsequent firearm-related harm and to assess impact on firearm injury.

"We estimate there were 36,142 more-than-expected handgun acquisitions in California from the election through the 6-week period following the Sandy Hook school shooting," said Hannah Laqueur, co-author of the study and an assistant professor of emergency medicine at UC Davis. "This represents an increase of more than 55 percent over expected volume during this 11-week period." The researchers found that cities with greater increases in the rate of handgun purchasing were more likely to see an increase in the rate of firearm injury.