I recently became aware of a Supreme Court case from 1994, Staples v. United States. This case involved a man who had been arrested for having an AR-15 with more than a few components of an M-16 fire control group installed inside of it including the selector, hammer, disconnector, and trigger.
Suspecting that the AR-15 had been modified to be capable of fully automatic fire, BATF agents seized the weapon. The defendant was indicted for unlawful possession of an unregistered machinegun in violation of the NFA.
At trial, BATF agents testified that when the AR-15 was tested, it fired more than one shot with a single pull of the trigger. It was undisputed that the weapon was not registered as required by the NFA. The defendant testified that the rifle had never fired automatically when it was in his possession. He insisted that the AR-15 had operated only semiautomatically, and even then often requiring manual ejection of the spent casing and chambering of the next round. According to the defendant, his alleged ignorance of any automatic firing capability should have shielded him from criminal liability for his failure to register the weapon.
The trial court disagreed, and the man was convicted and sentenced to five years’ probation and a $5,000 fine. He appealed the conviction, and the appeals court agreed with the trial court, affirming his conviction. It was appealed and wound up at the SCOTUS level. Justice Thomas wrote the majority opinion, and let me tell you, there are some great quotes in that opinion.
The opnion says that the language of the statute provides little in the way of guidance in this case. The NFA is silent concerning the mens rea (intent) required for a violation. It states simply that “[i]t shall be unlawful for any person . . . to receive or possess a firearm which is not registered to him in the National Firearms Registration and Transfer Record.”
Nevertheless, silence on this point by itself does not necessarily suggest that Congress intended to dispense with a conventional mens rea element, which would require that the defendant know the facts that make his conduct illegal.
Staples v. United States, 1984
The Government argued in that case that Congress intended the NFA to regulate and restrict the circulation of dangerous weapons. Consequently, in the ATF’s view, this case fits in a line of precedent termed “public welfare” or “regulatory” offenses, in which SCOTUS understood that Congress sought to impose a form of strict criminal liability through statutes that do not require the defendant to know his conduct was illegal.
One money quote that I saw was this one:
The Government does not dispute the contention that virtually any semiautomatic weapon may be converted, either by internal modification or, in some cases, simply by wear and tear, into a machinegun within the meaning of the Act.
Give the case a read, and see what you can find.