Notes
Denials related to immigration status of buyers are not covered.
Sources
National Consortium for Justice Information and Statistics (mental health, domestic violence, felons, fugitives, drug use); Government Accountability Office (domestic violence); Virginia Tech Review Panel (Seung-Hui); National American Indian Court Judges Association, Snohomish County Multiple Agency Response Team (Fryberg); WSJ reporting (Kelley and Roof); Jefferson County Sheriff's Office (Harris and Klebold)
Photos: Getty Images; Beretta; Ruger; Hi-Point