Supreme Court decision could unravel key plank of vaunted Mass. gun safety law

As they tout the strength of the state’s gun laws amid a spate of deadly mass shootings, Massachusetts legislators and advocates are also warily eyeing an impending Supreme Court decision that has the potential to gut the state’s strict licensing rules and prompt a scramble on Beacon Hill to respond.

The Supreme Court could soon rule on — and, many legal observers expect, strike down — a New York law that puts strict limits on people carrying a handgun outside their home. The reverberations would rattle through Massachusetts and a handful of other states with similar laws, potentially invalidating firearm statutes that supporters say help keep residents safe.

“It’s a change that would have a lot of day-to-day consequences. In the places you go to in public, there could be people carrying firearms where there weren’t before,” said Cody Jacobs, a lecturer at the Boston University School of Law and a former staff attorney at what is now the Giffords Law Center to Prevent Gun Violence.

Jacobs and others acknowledge that it’s unclear how broadly the Supreme Court could craft such a decision, which would dictate the legislative response. “But,” he said, “even a narrow decision striking down New York’s law is going to have a big impact on Massachusetts.”

In New York, state law requires people to apply for a permit to carry a concealed gun, and to show “proper cause,” or a special need to carry a gun outside their home that goes beyond a generalized social danger or fear.

Massachusetts has a similar standard. Under state law, local police chiefs, who serve as the state’s licensing authority, may issue a license to carry — which allows the purchase and carrying in public of a handgun — to someone if that person shows a “good reason” to have one, including if they “fear injury to the applicant or the applicant’s property.”

Massachusetts also gives chiefs wide discretion in determining whether someone is suitable to have a license to carry. That means the application of the law can vary widely, including in the restrictions local officials can place on licenses.

In Boston, for example, city officials tell prospective applicants they could restrict a license to just hunting or recreational shooting, limiting a person to carrying the gun to and from the range. Or, if a person says they are applying for a license to carry because they want a gun for work — they may carry a lot of money on them and want protection, for example — the city could restrict the license to “business activities” only.

The Supreme Court recognized the Second Amendment as an individual right in 2008′s District of Columbia v. Heller, but the ruling was limited, protecting the right to keep a gun “in defense of hearth and home.”

In the case before it now, New York State Rifle & Pistol Association v. Bruen, the justices are weighing whether denying an application for a concealed carry license for “self defense” — outside the home and in public — violates the Second Amendment.

To be sure, the court could let current law stand. But many observers, citing justices’ line of questioning during oral arguments last year, expect the conservative majority to rule that the New York statute infringes on the right to keep and bear arms. And, as a result, “states will be much more limited in their ability to stop people from carrying guns,” said Kent Greenfield, a Boston College law professor.

“I’m very concerned,” said Representative David P. Linsky, a Natick Democrat who has regularly pushed proposals to expand the state’s gun laws. “As legislators, we have to be very vigilant of a potentially bad Supreme Court ruling.”

The decision could land at a time when debate is already raging in state capitols and Washington, D.C., about whether officials should reshape their gun laws in response to a series of shootings, including the massacre of 19 students and 2 teachers at a Uvalde, Texas, elementary school.

In recent days, Massachusetts officials have touted the state’s laws as a blueprint for others to follow. “Massachusetts gun laws have been proven to work,” Governor Charlie Baker said Monday.

How much the Supreme Court could force reshaping them remains to be seen. That includes questions of whether the court broadens its ruling beyond New York’s specific “proper cause” standard to target officials’ ability to inject discretion into the permitting process.

If they do, “then, you’re talking about a tectonic shift,” said Jason A. Guida, an attorney and a former general counsel for Massachusetts’ Firearm Licensing Review Board.

In Massachusetts, for example, someone could technically be qualified for a license to carry — if they don’t have a criminal record, for example — but still be denied one by a local chief, who can consider a range of other factors, such as if police have been called to the person’s home or whether the applicant had been the subject of domestic violence complaints that didn’t result in arrests or charges.

But if the court determines that that layer of decision-making should be prohibited, “now you’re no longer allowing chiefs to use their discretion but instead they simply check boxes,” Guida said.

Legislative leaders said they are preparing for the possibility of portions of Massachusetts law to be invalidated, though time remains a factor. The Legislature’s formal sessions are scheduled to end July 31, and lawmakers are entering a stretch that typically becomes a bottleneck of unfinished work and complex legislation.

Representative Michael S. Day, the House chairman of the judiciary committee, said lawmakers believe that their current laws are constitutional, and have created what he called a “strong net of rules” on firearms.

“If that net is loosened at all, we’ll be able to move very quickly in response to it,” said Day, a Stoneham Democrat.

Lawmakers are also still weighing a range of other bills that would expand already stringent laws. The Legislature’s committee on public safety has been weighing bills addressing so-called ghost guns, or firearms that lawmakers say have evaded regulation because they don’t have a serial number and are typically sold in pieces or in kits. Other legislation would ban the manufacturing of assault weapons in Massachusetts, except for law enforcement and military purposes.

Discussions over pursuing wide-ranging legislation that includes several components are a “work in progress,” said Senator Jamie Eldridge, the judiciary committee’s Senate chairman. But a potential response to the Supreme Court could also factor into a wider package.

“Part of it is a focus on, ‘OK, when does the Bruen case come down?’ ” said Eldridge, an Acton Democrat. “And then, how do state legislators react regarding protecting our state’s laws if the Supreme Court is basically invalidating Massachusetts law?”

Matt Stout can be reached at matt.stout@globe.com. Follow him @mattpstout.