Half of all suicides and two-thirds of all homicides in the United States involve firearms. 1 Previous analyses of individual-level data have indicated that there is strong evidence that access to firearms is associated with completed suicide while there is moderate evidence that access is associated with homicide victimization. 2 And a history of psychiatric illnesses has been linked with a significantly increased risk of suicide completion (method non-specific). 3 Though some evidence suggests that individuals with a mental illness are significantly more likely to attempt suicide using a firearm than other means, 4 the extent that any restriction of means would have on completed suicide among individuals exhibiting suicidal behaviors is not clear. Some empirical studies of policies aimed at restricting firearm access to high-risk individuals have shown a reduction in suicide, 5 while others have shown mixed results. 6 Nevertheless, mental health background checks for prospective firearm purchasers are not universal and vary widely between countries, states, and even metropolitan areas.