Caetano v. Massachusetts, 577 U.S. ___ (2016)
Not familiar with this one.
Caetano was a case challenging a stun-gun ban in Massachusetts. It is very useful to cite to dispense with the typical anti-gunner idiocy that the 2ndA only protects muskets . . .
This was a per curiam decision which are short and unsigned and typically represent a decision on an issue that is not believed controversial (within the Court).
The Mass. state supreme court held that since stun-guns were not in common use at the time the 2ndA was enacted, they could be banned.
SCOTUS relied on
Heller which contains a paragraph dispelling that idea (internal citations removed):
"Some have made the argument, bordering on the frivolous, that only those arms in existence in the 18th century are protected by the Second Amendment . We do not interpret constitutional rights that way. Just as the First Amendment protects modern forms of communications, . . . , and the Fourth Amendment applies to modern forms of search, . . . , the Second Amendment extends, prima facie,to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding."
The Court wrote in
Caetano v. Massachusetts:
"The Court has held that “the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding,” District of Columbia v. Heller, 554 U. S. 570, 582 (2008), and that this “Second Amendment right is fully applicable to the States,” McDonald v. Chicago, 561 U. S. 742, 750 (2010). In this case, the Supreme Judicial Court of Massachusetts upheld a Massachusetts law prohibiting the possession of stun guns after examining “whether a stun gun is the type of weapon contemplated by Congress in 1789 as being protected by the Second Amendment.” 470 Mass. 774, 777, 26 N. E. 3d 688, 691 (2015). . . .
. . . the [Massachusetts] court explained that stun guns are not protected because they “were not in common use at the time of the Second Amendment’s enactment.” Id., at 781, 26 N. E. 3d, at 693. This is inconsistent with Heller’s clear statement that the Second Amendment “extends . . . to . . . arms . . . that were not in existence at the time of the founding.” 554 U. S., at 582. . . .
. . . the explanation the Massachusetts court offered for upholding the law contradicts this Court’s precedent. Consequently, the . . . judgment of the Supreme Judicial Court of Massachusetts is vacated, and the case is remanded for further proceedings not inconsistent with this opinion."
Caetano is also useful because it dispenses with any argument that there is some numerical value that must be attained, for an arm to be deemed "in common use".