The case is O'Neil v. Neronha, decided today by Judge William E. Smith (D.R.I.); Judge Smith expresses his disapproval of D.C. v. Heller (pp. 9-10 n.7), but applies it to hold that the stun gun ban is unconstitutional. Congratulations to lawyers Alan Beck, Stephen Stamboulieh, and Frank Saccoccio on the victory.
Shortly after D.C. v. Heller was decided, stun guns were banned in seven states, D.C., the Virgin Islands, several substantial cities, and some smaller towns. (I cataloged these in Nonlethal Self-Defense, (Almost Entirely) Nonlethal Weapons, and the Rights To Keep and Bear Arms and Defend Life, 62 Stanford Law Review 199 (2009).) But in Caetano v. Massachusetts (2016), the Court signaled that stun gun bans may well be unconstitutional, and lower courts and legislatures have largely heard the message.
