Background: In 2016, firearms killed 38,658 people in the United States. Federal law
requires licensed gun dealers, but not private parties, to conduct background checks on
prospective firearm purchasers with the goal of preventing prohibited persons from obtaining
firearms. Our objective was to estimate the effect of the repeal of comprehensive background
check laws—requiring a background check for all handgun sales, not just sales by licensed
dealers—on firearm homicide and suicide rates in Indiana and Tennessee. Methods: We …