Staples v. United States
Supreme Court of the United States · Decided May 23, 1994 · Core case
Full citation
Staples v. United States, 511 U.S. 600 (1994).
VerifiedQuotes, pinpoints and citation checked word for word against the opinion; facts checked against the opinion before publication. October 20, 2026.This brief explains the opinion as issued. Later treatment and current-law status are not assessed here.
Harold E. Staples
rifle ownerpetitioner
United States
prosecutor
Brief
Facts
Local police and federal agents executing a search warrant at Staples's home seized an AR-15 rifle. The AR-15 is manufactured as a semiautomatic firearm, but the metal stop on its receiver had been filed away, and it had been assembled with M-16 parts, including a selector switch, hammer, disconnector, and trigger. Staples was indicted under 26 U.S.C. section 5861(d) for possessing an unregistered machinegun. The National Firearms Act defines a machinegun as any weapon that shoots, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger. At trial, government agents testified the rifle fired multiple shots with one trigger pull. Staples, whose gun was unregistered, testified that it had never fired automatically in his possession and had operated only semiautomatically, and even then imperfectly. He asked for a jury instruction that the Government must prove he knew the gun would fire fully automatically. The district court refused and instructed the jury that the Government needed only to prove Staples knew he was dealing with a dangerous device of a type that would alert one to the likelihood of regulation.
Issue
Does a conviction for possessing an unregistered machinegun under 26 U.S.C. section 5861(d) require the Government to prove that the defendant knew the weapon had the characteristics that brought it within the statutory definition of a machinegun?
Holding
Yes. To convict a defendant under 26 U.S.C. section 5861(d) for possessing an unregistered machinegun, the Government must prove beyond a reasonable doubt that the defendant knew of the physical features of the weapon that brought it within the statutory definition of a machinegun. The Court called its holding a narrow one.
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