Proposals for universal background checks would require almost all firearms transactions in the United States to be recorded and go through the National Instant Criminal Background Check System (NICS), closing what is sometimes called the private sale loophole.
In a 2017 survey, a panel of 32 scholars of criminology, public health and law rated universal background checks as the most effective policy to prevent gun deaths, ranking it #1 of 29 possible gun-related policies. Universal background checks enjoy high levels of public support; a 2016 representative survey found 86% of U.S. registered voters supported the measure.
Currently, federal law requires background checks (through the National Instant Criminal Background Check System) only for guns sold through licensed firearm dealers, which account for 60% of all gun sales in the United States. Current federal law allows people not "engaged in the business" of selling firearms to sell firearms without a license or records. In effect, that would mean that two out of every five guns sold in the United States change hands without a background check. The Coalition to Stop Gun Violence (CSGV) states that the National Instant Criminal Background Check System has prevented over two million convicted felons and other prohibited persons from purchasing firearms. According to the CSGV, the law also has a prohibitive effect, that deters illegal purchases.
In November 1998, President Bill Clinton directed the U.S. Secretary of the Treasury and the U.S. Attorney General (A.G.) to provide recommendations concerning the fact that 25 percent or more of sellers at gun shows are not required to run background checks on potential buyers. This was called the gun show loophole. Two months later, Gun Shows: Brady Checks and Crime Gun Traces was released. The Secretary and the A.G. made seven recommendations, including expanding the definition of "gun show," and reviewing the definition of "engaged in the business."