On Thursday, the Connecticut Supreme Court put the gun industry on notice: If you advertise your weapons as alluring tools for mass slaughter, you will face consequences—at least in this state.

By a 4–3 vote, the court revived a lawsuit by the families of Sandy Hook victims alleging that Remington recklessly marketed its Bushmaster AR-15–style weapon for “illegal, offensive purposes,” contributing to Adam Lanza’s murder of 26 people at their elementary school. The majority ruled that a federal law does not shield Remington from liability for wrongful advertising, permitting a jury to determine whether Remington can be held liable. Its decision is a stunning blow to the firearms industry, which has long claimed near-absolute immunity from such lawsuits. And it allows the plaintiffs to uncover private, potentially damning communications that will reveal how Remington peddles its lethal products to the public.

Thursday’s ruling in Soto v. Bushmaster revolves around two laws: the Connecticut Unfair Trade Practices Act (CUTPA) and the Protection of Lawful Commerce in Arms Act (PLCAA). CUTPA is a straightforward state regulation that prohibits wrongful advertising—marketing a product in an unfair, unethical, or dangerous manner. The PLCAA, by contrast, is a highly unusual federal statute that limits Americans’ ability to sue gun manufacturers and sellers. Under this law, the gun industry is largely immune from suit in cases when its products are used illegally, even when its own negligence leads to firearm injuries and deaths.

Passed in 2005, the PLCAA was designed to shield the gun industry from the kind of lawsuits filed against tobacco companies in the 1990s. These suits accused cigarette manufacturers of creating a public health crisis by violating consumer protection statutes. The National Rifle Association, which described PLCAA as its No. 1 legislative priority, did not want the firearm industry subject to similar liability. The organization hoped that courts would interpret the law as a sweeping grant of immunity from the liability that every other industry, even nonlethal ones, must guard against. For instance, car companies include disclaimers in commercials advising viewers not to try various dangerous stunts themselves. Pharmaceutical companies list possible side effects in each ad. But firearm advertisements rarely, if ever, warn viewers against unsafe use of weapons because they believe federal law absolves them of their obligations to consumers.

Because of the PLCAA, families of the Sandy Hook massacre and other mass shootings cannot sue gun shops and manufacturers for negligently making or selling assault weapons. But the Sandy Hook families pursued a different legal theory: They argued that Remington’s advertisements for the AR-15–style weapon ran afoul of CUTPA by promoting unethical and illegal use of the weapon. Their lawsuit cited multiple ads that depicted the gun not as a tool of home defense, hunting, or sport, but as a weapon of war meant to kill a large number of people in a small amount of time. Remington advertised the gun as “the ultimate combat weapons system” used by the armed forces in theaters of war. It depicted a close-up of the gun with the slogan “Forces of opposition, bow down. You are single-handedly outnumbered.” It touted the weapon as an “uncompromising choice” with “military proven performance.” As the Connecticut Supreme Court explained, the thrust of Remington’s ads was that the gun would “enable a shooter to inflict unparalleled carnage.”

The lawsuit cited multiple ads that depicted the gun not as a tool of home defense, hunting, or sport, but as a weapon of war.

The plaintiffs relied on CUTPA in an effort to work around the PLCAA, because the federal statute includes an important exception. While it bars most negligence suits, the PLCAA permits claims alleging that a gun manufacturer or seller “knowingly violated a State or Federal statute applicable to the sale or marketing of the [firearm], and the violation was a proximate cause of the harm for which relief is sought.” If CUTPA is “applicable” to the sale of firearms, then, the plaintiffs’ wrongful advertising suit is not prohibited by the PLCAA.

Federal judges have been divided on the question of whether a broad regulation of trade and public safety is “applicable” to the “sale or marketing” of guns. Some have held that a law must be designed to regulate firearms in order to qualify; others assert that any law that can be reasonably interpreted to regulate the gun trade counts as “applicable.” The Connecticut Supreme Court chose this latter interpretation, finding that the word’s “ordinary, dictionary meaning” is simply “capable of being applied.”

From there, the majority easily concluded that CUTPA is “applicable” to gun marketing by forbidding the advertisement of weapons for “illegal, offensive purposes.” This wrongful advertising, moreover, may have been “a causal factor in increasing the casualties of the Sandy Hook massacre.” As the majority explained, the plaintiffs allege that Remington sought to “expand the market for [its] assault weapons through advertising campaigns that encouraged consumers … to launch offensive assaults against their perceived enemies.” PLCAA does not stop these plaintiffs from asking a jury to hold Remington “accountable for the injuries wrought by such unscrupulous marketing practices.” As the Sandy Hook families’ attorney said at oral arguments, “Remington may never have known Adam Lanza, but they had been courting him for years.”

What happens now? As the court repeatedly pointed out, the plaintiffs have not actually won their lawsuit; they’ve merely secured the ability to make their case to a Connecticut jury. In the process, they will seek extensive discovery from Remington, poring over its strategy for selling guns. The company has fought to keep its internal communications secret, and gun rights advocates have long hoped to expose the industry’s alleged disregard for life and safety when marketing weapons. Now, at long last, the Sandy Hook families may reveal its tactics in court.

There remains, however, a possibility that the U.S. Supreme Court could first intervene. Would the court’s conservatives dare deny justice to the grieving families of a notorious massacre? It seems possible, though Chief Justice John Roberts must recognize the atrocious optics of the court’s intervention. On the other hand, the three dissenters from Thursday’s ruling essentially invited a reversal from “those who ply their judicial craft at One First Street.” The Supreme Court could wait until a jury has rendered its verdict—but by that point, Remington will have suffered through discovery.

It is not difficult to envision Roberts and his fellow conservatives stepping in to smack down the Connecticut Supreme Court and closing the courthouse doors to Sandy Hook families. That would be a travesty, but at the very least, it might invite more public scrutiny to the PLCAA, a law unlike any other. Passed at the behest of the gun industry, designed to condone corporate irresponsibility, and anathema to fundamental principles of liability, the statute is a global outlier that permits American gun sellers to pollute the world with illegal weapons. Its repeal should be a goal of any politician who believes states should be permitted to allow citizens to hold the gun industry liable for the slaughter it has enabled.