1. Firearm Injury and Policy Research Program, Harborview Injury Prevention and Research Center, University of Washington, Seattle (all authors); Department of Psychiatry and Behavioral Science, School of Medicine, University of Washington, Seattle (Prater); School of Social Work, University of Washington, Seattle (Conrick, Moore); Department of Pediatrics (Rivara) and Department of Epidemiology, School of Public Health (Rowhani-Rahbar), University of Washington, Seattle.