By Nicole Kravitz-Wirtz , Rocco Pallin , Matthew Miller , Deborah Azrael , Garen J Wintemute

Objective: To describe the prevalence of and factors associated with firearm ownership; the types, subtypes, and quantity of firearms owned; and when, where and why firearms were acquired in California.

Methods: A cross-sectional analysis of a state-representative, probability-based, internet survey of California adults was conducted in September-October 2018 (n=2558; completion rate 49%). Household firearm ownership was ascertained for all respondents; personal firearm ownership was ascertained only among respondents who reported living in a home with firearms; and information on the types and quantity of firearms owned and details about recently acquired firearms came from firearm owners only.

Findings: Roughly one in four (25%, 95% CI 22% to 28%) California adults live in a home with a firearm, including 4.2 million adults-14% (95% CI 13% to 16%) of the adult population who personally own a firearm. These owners collectively own an estimated 19.9 million firearms (8.9 million handguns). Approximately half (48%, 95% CI 34% to 61%) of the firearm stock in California is owned by the 10% (95% CI 6% to 14%) of owners who own 10 or more firearms, though more than half (54%, 95% CI 47% to 62%) of owners in the state own only one or two firearms. Most (69%, 95% CI 63% to 75%) owners purchased their last firearm from a firearm retailer, usually a handgun purchased primarily for protection against people.

Conclusion: This study provides the most detailed and up-to-date information available on firearm ownership and acquisition in California. Results can inform firearm violence prevention efforts and public health, safety, and policy development in California and nationally.

Injury Prevention, Volume 26, Issue 6, 2020.