Massachusetts being Massachusetts, legislators there had passed a law banning stun guns. Why? Because they could and besides, why should Bay Staters have any more personal protection options than their elected representatives can possibly get away with prohibiting?
Jaime Caetano was arrested for carrying a stun gun because she feared an abusive boyfriend. The Massachusetts high court upheld her conviction, ruling that stun guns weren’t protected under the Second Amendment because they didn’t exist when the Bill of Rights were drafted.
Her conviction was appealed and in 2016, the US Supreme Court, in an unusual unanimous decision, reversed that judgement, ruling that the Second Amendment protects more than just flintlocks and blunderbusses. SCOTUS sent the case back to the Massachusetts high court for more arguments.
Now the Massachusetts high court has ruled that, in fact, stun guns qualify as “arms” and, as such, are protected under the Second Amendment.
Today’s decision doesn’t really much discuss the other arguments — e.g., the argument that stun guns are “dangerous and unusual,” because they aren’t common these days, or the argument that stun gun bans pass heightened scrutiny as public safety measures — but just concludes that,
Having received guidance from the Supreme Court …, we now conclude that stun guns are “arms” within the protection of the Second Amendment. Therefore, under the Second Amendment, the possession of stun guns may be regulated, but not absolutely banned. Restrictions may be placed on the categories of persons who may possess them, licenses may be required for their possession, and those licensed to possess them may be barred from carrying them in sensitive places, such as schools and government buildings. But the absolute prohibition … that bars all civilians from possessing or carrying stun guns, even in their home, is inconsistent with the Second Amendment and is therefore unconstitutional.
As Volokh points out, since the Heller decision, stun gun bans have been invalidated or repealed in about a dozen cities, states and territories around the US.
Stun gun bans remain in effect, to my knowledge, in Hawaii, New York, Rhode Island, and Wilmington (Delaware), plus some smaller towns. The Hawaii and New York laws are being challenged in court.
Established case law would seem to to be firmly on the side of those suing to overturn the bans.
The tradeoff: since they’re protected under the 2A, that means states and local governments can, just like firearms, ban prohibited persons from owning stun guns, designate no-go areas like hospitals and public transportation, and otherwise regulate their use. You takes the good with the bad.