NEWS | April 23, 2018

Study of firearm deaths over 16-year period in California finds shift in firearm homicides and suicides


A study of firearm deaths in California from 2000-2015 by the UC Davis Violence Prevention Research Program (VPRP) has found that firearm homicides were largely an urban problem at the start of the study period, however, falling rates in urban counties resulted in more rural areas in the central part of the state having the highest rates of firearm homicide by 2015. It also found firearm suicides in California increased slightly since the mid-2000s, were three times higher in rural counties and were highest among whites.

Firearm california mapThe study appears in the May issue of Annals of Epidemiology. The research assesses the variations in firearm-related deaths at the county level, where many policies and programs affecting firearm ownership and use are located and where many public health and law enforcement interventions are designed and implemented.

The researchers found that the rate of firearm homicide statewide increased from 4.19 deaths per 100,000 residents in 2000 to a peak of 5.05 deaths per 100,000 in 2005; since then it declined to a low of 3.13 in 2014 but increased slightly in 2015. The absolute rise and fall in homicide was most substantial for black men, whose rate peaked in 2005 at 47 deaths per 100,000, and fell 32 percent to 31 deaths per 100,000 by 2015. On average, the homicide rate for black men was 4.5 times the rate for Hispanic men, the group at next highest risk. The firearm homicide rate among men was 7.2 times the rate for women.

“We found important variations in firearm deaths in California over time and across counties from 2000 to 2015,” said Veronica Pear, a research data analyst with the UC Davis Violence Prevention Research Program and first author of the study.

“Consistent with existing literature, we found firearm homicide to be largely an urban problem at the start of the study period, however, falling rates in urban counties, driven by reductions in homicides in Los Angeles County among men of color, resulted in more rural areas in the central part of the state having the highest rates of firearm homicide by 2015.”

Pear attributes the decline in firearm homicides in California’s most populous counties to reductions in gang violence, particularly among Hispanic men. She hopes researchers will investigate the cause of this reduction in violence in future studies.

Firearm suicides, in contrast, increased slightly over the study period and were concentrated in rural counties and among whites, with older white men having the highest rates and number of deaths.

thumbnail of infographicThe statewide rate of firearm suicide decreased from 4.64 deaths per 100,000 in 2000 to a low of 3.75 deaths per 100,000 in 2006, thereafter plateauing around 4 deaths per 100,000. The firearm suicide rate among men was 8.5 times the rate for women. White men had the highest number of firearm suicides across all ages, peaking in their 50s. Suicides for nonwhite men follow a different trajectory, with the most deaths occurring between the ages of 20 and 29 years.

“Over the age of 80 years, white men had nearly 30 times the number of firearm suicides as Hispanic men, the only other racial or ethnic group with counts large enough to report,” Pear said. “For men and women combined, whites also had more than six times the number of deaths due to firearm suicide than any other group.”

For the study, VPRP researchers evaluated 50,921 firearm fatalities from 2000 to 2015 in the Multiple Cause of Death database for California to describe changes across time and geographic distribution among the population throughout the state. They only included homicides and suicides in their analyses, which represented 48.9 percent and 46.5 percent of all fatalities, respectively.  The small number of deaths by legal intervention, unintentional or undetermined intent were excluded from the study.  

“We hope this paper can be used by public health practitioners in creating targeted interventions, policymakers who allocate resources, and public health scientists who want to better understand factors that contribute to firearm violence,” she said. “We also hope it can serve as a template for researchers in other states to create similar profiles of within-state firearm mortality.”

Other authors of the study include Alvaro Castillo-Carniglia, Rose M.C. Kagawa, Magdalena Cerdá and Garen J. Wintemute, all from the UC Davis Violence Prevention Research Program.

The study, “Firearm mortality in California, 2000-2015: the epidemiologic importance of within-state variation,” was funded with a grant from the Heising-Simons Foundation (2016-219), the state of California through the University of California Firearm Violence Research Center, the Robertson Fellowship in Violence Prevention Research and Becas Chile as part of the National Commission for Scientific and Technological Research (CONICYT). (

The UC Davis Violence Prevention Research Program is a multi-disciplinary program of research and policy development focused on the causes, consequences and prevention of violence. Studies assess firearm violence and the connections between violence, substance abuse and mental illness. VPRP is home to the University of California Firearm Violence Research Center, which launched in 2017 with a $5 million appropriation from the state of California to fund and conduct leading-edge research on firearm violence and its prevention.