In 2015, the state’s highest court had ruled that the ban did not violate the Second Amendment. But in 2016, the US Supreme Court held that the SJC had erred in its decision and sent the case back for reconsideration.

“We conclude that the absolute prohibition against civilian possession of stun guns . . . is in violation of the Second Amendment,” the court said.

Reversing course, the Massachusetts Supreme Judicial Court on Tuesday struck down a state law banning civilian possession of stun guns.

The case that came before the two courts was ultimately dismissed, so the SJC had not revisited its ruling.


But in a case decided Tuesday, the SJC acceded to the Supreme Court ruling.

“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,” Chief Justice Ralph Gants wrote in an unanimous decision.

“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,” Gants wrote. “But the absolute prohibition in [state law] that bars all civilians from possessing or carrying stun guns, even in their home, is inconsistent with the Second Amendment.”

The court said it could not partially invalidate the state law — it had to be completely invalidated. It gave the Legislature about three months to decide whether to revise the law, or it will lapse. A spokesperson for House Speaker Robert A. DeLeo said he intends to file legislation within two months.

Chris Pinto, chairman of the advocacy group Massachusetts Gun Rights, said Tuesday’s ruling was long overdue. Stringent regulation of stun guns, he said, “keeps women at risk and denies them a way to protect themselves.”


“The idea in the Legislature is this device could be used for bad purposes,” he said. “But your fear shouldn’t take away my rights.”

Jake Wark, a spokesman for the Suffolk district attorney’s office, said in a statement that the state’s “reasonable restrictions on firearms are among the most effective in the nation.”

“We believe the current restrictions on stun guns can be updated in a manner consistent with the high court’s ruling,” he said.

Stun guns are electronic devices, such as Tasers, that administer an electric shock to immobilize, but not kill, an individual. Law enforcement officials are exempt from the state ban.

Danny McDonald of the Globe staff contributed to this report.