On November 12, the Supreme Court declined to hear Remington’s challenge to a lawsuit by families of victims of the 2012 Sandy Hook massacre in Newtown, Connecticut.

The gunmaker appealed to the nation’s highest court after the Connecticut Supreme Court ruled in March that family members of nine Sandy Hook victims could go to trial against Remington, the maker of the rifle used in the attack, and several other defendants in the gun industry.

The Supreme Court’s decision to decline the case allows the suit to proceed to trial, and is the latest event in a legal battle that has been churning since 2014. The Connecticut Supreme Court ruling in March resolved the very simple question of whether the lawsuit should exist at all. But no court has yet addressed the question at the center of this case: Do Remington and its distributors and sellers actually bear some responsibility for the Sandy Hook shooting? The victims’ families are now on the verge of getting that question, which has broad implications for the gun industry, in front of a jury.

Where was the case before the March ruling?

In 2016, a trial court judge, Barbara Bellis, found that a federal law called the Protection of Lawful Commerce in Arms Act (PLCAA) barred the family members from seeking damages from the companies that made and sold a military-grade weapon to the Newtown shooter’s mother. The shooter used a Bushmaster XM15-E2S rifle to kill 26 people — including 20 elementary school children — in just over four minutes. (Bushmaster is owned by Remington, which claims to be America’s oldest gunmaker.)

What happened in March?

The Connecticut Supreme Court ruled that just one of the plaintiffs’ many claims could live to see another day. Until Remington’s challenge to the nation’s high court, lawyers for the Newtown families were able to move forward with their argument that the gun maker marketed its products in an especially dangerous way. Timothy Lytton, a law professor at Georgia State University and PLCAA expert, describes the plaintiffs’ legal theory like this, “They’re saying that Remington was drawing high-risk people out of the woodwork to buy their product.”

Remington’s edgy marketing choices included promoting the Bushmaster XM15 as ‘‘the ultimate combat weapons system,” and touting its offensive capabilities. In advertisements, Remington depicted the gun in the hands of soldiers patrolling the jungle. One advertisement for the XM15-E2S included the slogan: ‘‘Forces of opposition, bow down. You are single-handedly outnumbered.’’

The families allege that Remington’s hyper-militaristic portrayal of the XM15 runs afoul of a Connecticut law that prohibits companies from marketing their products in unsafe and unscrupulous ways. That law is called the Connecticut Unfair Trade Practices Act (CUTPA), and it’s a run-of-the-mill consumer protection statute that exists in some form in every state.

The Connecticut Supreme Court argued that this question — whether Remington’s marketing violated CUTPA — should go to a jury. If a jury finds that the gunmakers unscrupulously advertised a dangerous product, the gunmakers could be held liable for the deaths at Sandy Hook.

But wait … what about the gun industry liability shield?

Often, the federal PLCAA law means sudden death for any lawsuit against a gun company. But the statute has a few holes through which lawsuits can pass. If a gun maker or gun seller knowingly breaks the law, and there are injuries because of that violation, then victims can sue for damages. For example, it is a crime for a gun store to sell a weapon to a known felon, and the gun store can be sued if that felon uses it to kill people.

In this case, the plaintiffs are arguing that Remington’s unethical marketing violated CUTPA and drew the Sandy Hook shooter to the weapon.

So what happens now?

The Supreme Court’s decision to not hear the case means that the Connecticut Supreme Court ruling stands, and the case can, at long last, go to trial.

What did the gun companies ask the Supreme Court to consider?

They wanted the nation’s high court to consider whether PLCAA kicks this case out of court for good. Remember how I said that victims of gun violence can get around the law and sue a gun manufacturer if it violated a law? Remington and the other Sandy Hook defendants asked the Supreme Court, “Well, violate what laws exactly?”

The gun company defendants asked the Supreme Court to declare that gun companies can be sued only when they violate gun-specific laws. There are laws on the books that speak directly to the sale and distribution of guns, like prohibited purchaser laws. But then there are laws like Connecticut’s unfair trade practices law, which are broad trade regulations that address far more than just firearms. Are violations of either type of law a way around PLCAA? Federal courts are currently divided on this issue. (There’s more to this, and if your curiosity is piqued, please read this helpful explanation by Lytton in The Conversation.)

But since the Connecticut Supreme Court’s approach now stands, the law protecting lawful arms sales is much more vulnerable than it has been in the past, and gun companies could potentially be exposed to a “flood of lawsuits across the country.” Remember, every state has its own CUTPA-like law.

What are the implications of the case going to trial in Connecticut?

This would be a very big deal, because trials against gun companies rarely happen, thanks to the Protection of Lawful Commerce in Arms Act. This case would be one of a handful in which gun companies are forced to cough up documents on their manufacturing, marketing, and distribution practices. Those documents could answer some of the many open questions about the connection between above-board manufacturers and the black market for firearms. Right now, we only have hints about how gunmakers might facilitate the illicit gun trade.

It’s hard to say exactly what the Sandy Hook families could unearth through discovery in the Connecticut lawsuit, but we’re starting from a place of little knowledge. At oral arguments in 2017, the lawyer for the families told a panel of judges, “Remington may never have known [the gunman], but they had been courting him for years.” The plaintiffs are looking for information that would tell them whether that is true.