United States v. Miller, 307 U.S. 174 (1939), was a landmark decision of the Supreme Court of the United States that involved a Second Amendment to the United States Constitution challenge to the National Firearms Act of 1934 (NFA). The case is often cited in the ongoing American gun politics debate, as both sides claim that it supports their position. Background The case involved a criminal prosecution under the 1934 National Firearms Act (NFA). Passed in response to public outcry over the St. Valentine's Day Massacre, the NFA requires certain types of firearms, such as fully automatic firearms and short-barrelled rifles and shotguns, to be registered with the Miscellaneous Tax Unit, which was later folded into what eventually became the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), then part of the Bureau of Internal Revenue, the ancestor of today's Internal Revenue Service. The $200 tax was to be paid at the time of registration and again if the firearm was ever sold. The defendants Jack Miller and Frank Layton were indicted on charges of unlawfully and feloniously transporting in interstate commerce from Oklahoma to Arkansas an unregistered double-barrel 12-gauge shotgun having a barrel less than 18 inches in length, in violation of the National Firearms Act, 26 U.S.C.S. § 1132c et seq. ("Act"). At trial in federal district court, the defendants filed a demurrer to the indictment alleging that the Act was not a revenue measure but an attempt to usurp police power reserved to the states and so was unconstitutional. Defendants further argued that the Act violated the Second Amendment to the United States Constitution. The district court held that the section of the Act that made it unlawful to transport an unregistered firearm in interstate commerce was unconstitutional as violative of the Second Amendment. It accordingly sustained the demurrer and quashed the indictment. The government took a direct appeal to the Supreme Court. In reality, the district court judge was in favor of the gun control law and ruled the law unconstitutional because he knew that Miller, who was a known bank robber and had just testified against the rest of his gang in court, would have to go into hiding as soon as he was released. He knew that Miller would not pay a lawyer to argue the case at the Supreme Court and would simply disappear. Therefore, the government's appeal to the Supreme Court would