Personal protection is a frequently cited reason for firearm ownership. However, access to firearms in the home has been associated with an increased risk of death from suicide and homicide among household members. In 1986, Kellermann and Reay reviewed all the gunshot deaths in King County, Washington, from 1978 to 1983, including 398 that occurred in the residence where the firearm was kept. They found that for every self-protection homicide involving a firearm kept in the home, there were 1.3 accidental deaths, 4.6 criminal homicides, and 37 suicides involving firearms. We sought to update this study, using King County data from 2011 to 2018.
Methods
The study was a population-based case series of firearm deaths in homes in King County, Washington, from 2011 to 2018 (population 2 233 163 in 2018). We used King County Medical Examiner’s Office (KCMEO) records and linked these records to the Washington Office of the Attorney General Homicide Investigation Tracking System (HITS) for homicides. Cases were excluded if the incident did not occur in a home, occurred outside of King County, occurred more than 1 year prior to death, or if the person was shot by the police. The eMethods in the Supplement provide details on case linking and definitions.
We categorized deaths as suicide, criminal homicide, self-defense homicide, unintentional death, or undetermined based on KCMEO and HITS records (eMethods in the Supplement). The incidence of firearm deaths in homes was calculated by dividing the number of deaths by the number of person-years at risk, using annual county population estimates. The relative mortality of each type of firearm death compared with self-defense homicide was calculated by dividing the incidence of each type of death by the incidence of self-defense homicide. STATA/SE statistical software (version 14, StataCorp) was used for analysis. Because all participants were deceased, the study did not require institutional review board review.
Results
Over the study period, 647 firearm deaths occurred in homes (3.9 per 100 000 person-years) (Figure). The median age of the persons killed by firearms was 48 (interquartile range [IQR], 30-64) years, and 541 (83.6%) were male (Table). Nearly all persons who committed suicide (502 [96.2%]) died at their own residence; whereas 57 persons killed by homicide (65.5%) died at their own residence, and 23 (26.4%) died at the residence of a friend or acquaintance. Of cases with a known firearm source, 114 persons who committed suicide (93.4%) used a firearm kept in the home. In contrast, homicide offenders brought the firearm to the home in 74 (81.3%) cases. Of the 99 homicides, 12 (12.1%) were self-defense. For each case of self-defense homicide, there were 0.9 unintentional deaths (95% CI, 0.4-2.1), 7.3 criminal homicides (95% CI, 4.0-13.3), and 44.1 suicides (95% CI, 24.9-78.1) in the home.
Discussion
This study of firearm-related deaths in the home in King County, Washington, using data from 2011 to 2018, found strikingly similar results to the study of Kellermann and Reay, using data from 1978 to 1983. Firearm-related deaths in the home are still more frequently the result of suicide or criminal homicide than self-defense homicide.
Among the limitations of this study is that we did not assess the rate of nonfatal firearm injuries or instances where an intruder was deterred with a firearm kept in the home. In addition, because we evaluated a single county, our findings may not be generalizable to strictly rural areas or states with differing levels of household firearm ownership and stringency of firearm laws. Finally, our findings are not directly comparable to those in the earlier study. We had incomplete data on the firearm source; these data were missing for 431 (66.6%) firearm deaths. Therefore, we included all firearm deaths that occurred in homes, not just those that occurred in homes where the firearm was kept, as was the case in the earlier study.
These findings suggest that potential benefits of firearm ownership for personal protection need to be weighed against the risk of loss of life from suicide and criminal homicide.