Bump Stocks

 Cargill v. Garland (5th Cir. 2023):

Cargill is correct. A plain reading of the statutory language, paired with close consideration of the mechanics of a semi-automatic firearm, reveals that a bump stock is excluded from the technical definition of “machinegun” set forth in the Gun Control Act and National Firearms Act. 

But even if that conclusion were incorrect, the rule of lenity would still require us to interpret the statute against imposing criminal liability. A rich legal tradition supports the “well known rule” that “penal laws are to be construed strictly.” United States v. Wiltberger, 18 U.S. (5 Wheat.) 76, 94–95 (1820). As Chief Justice Marshall explained long ago, the rule “is founded on the tenderness of the law for the rights of individuals; and on the plain principle that the power of punishment is vested in the legislative, not in the judicial department. It is the legislature, not the Court, which is to define a crime, and ordain its punishment.” Id. at 95. 

The Government’s regulation violates these principles. As an initial matter, it purports to allow ATF—rather than Congress—to set forth the scope of criminal prohibitions. Indeed, the Government would outlaw bump stocks by administrative fiat even though the very same agency routinely interpreted the ban on machineguns as not applying to the type of bump stocks at issue here. Nor can we say that the statutory definition unambiguously supports the Government’s interpretation. As noted above, we conclude that it unambiguously does not. But even if we are wrong, the statute is at least ambiguous in this regard. And if the statute is ambiguous, Congress must cure that ambiguity, not the federal courts.

This is an en banc decision.