In 1939, through the court case United States v. Miller, the Supreme Court of the United States ruled that Congress could regulate interstate selling sawed-off shotguns through the National Firearms Act of 1934, deeming that such a weapon has no reasonable relationship with the efficiency of a well regulated militia. In 1968, following the spree of political assassinations including: the assassination of John F. Kennedy, the assassination of Robert F. Kennedy, and the assassination of Martin Luther King Jr, President Lyndon B. Johnson, pushed Congress for the Gun Control Act of 1968 ("GCA"). It repealed and replaced the FFA, regulated “destructive devices” (such as bombs, mines, grenades, and other explosives), expanded the definition of machine gun, required the serialization of manufactured or imported guns, banned importing military style weapons, and imposed a 21 age minimum on the purchasing of handguns from FFLs. The GCA also prohibited selling of firearms to felons and the mentally ill. In 1986, contrary to prior gun legislation, the Firearm Owners Protection Act ("FOPA") (1986), passed under the Ronald Reagan administration, enacted protections for gun owners. It prohibited a national registry of dealer records, limited ATF inspections to conduct annual inspections (unless multiple infractions have been observed), allowed licensed dealers to sell firearms at "gun shows" in their state, and loosened regulations on the sale and transfer of ammunition. However the FOPA also prohibited civilian ownership or transfer of machine guns made after May 19, 1986, and redefined "silencer" to include silencer parts. In 1993, the Brady Handgun Violence Prevention Act, named after a White House press secretary who was disabled during the attempted assassination of Ronald Reagan, was signed into law under the presidency of Bill Clinton. This act required that background checks must be conducted on gun purchases and established a criminal background check system maintained by the FBI. In 1994, the Violent Crime Control and Law Enforcement Act was signed into law under the presidency of Bill Clinton, which included the Federal Assault Weapons Ban, effectively banned the manufacturing, selling, and possession of specific military-style assault weapons such as AR-15 style rifles and banned high-capacity ammunition magazines that held over 10 rounds. Banned arms that were previously legally possessed were grandfathered. The ban expired in September 2004. In 2003, the Tiahrt Amendment proposed by Kansas Representative, Todd Tiahrt, limited the ATF to only release information from its firearms trace database to only law enforcement agencies or a prosecutors in connection with a criminal investigation.