More than 14 months after victims’ families sued Bushmaster Firearms in the aftermath of the mass shooting in Newtown, Connecticut, the lawsuit is finally approaching the first critical test of a novel liability claim: Whether or not the riflemaker can be held responsible for the Sandy Hook massacre because of how it has marketed a military-style weapon to civilians.

The case was filed by relatives of nine of the 26 children and adults Adam Lanza killed with a Bushmaster AR-15 rifle. Bushmaster argues that the suit is barred under the decade-old federal Protection of Lawful Commerce in Arms Act (PLCAA), which shields the gun industry from liability claims. A Connecticut state judge has scheduled a hearing for February 22 on the defendants’ motions to dismiss.

If the case survives this round—hardly a given, considering the difficulties other plaintiffs have encountered in trying to break through PLCAA’s immunity shield—the lawsuit would then head into uncharted territory, as the Newtown plaintiffs seek to use the industry’s marketing tactics against it.

Those tactics, never tested before under PLCAA, dominate the allegations spelled out in the plaintiffs’ complaint. It quotes several advertisements from a catalog aimed at civilian gun buyers that is adorned with action photos of camouflage-clad soldiers and police in body armor. One reads, “Forces of opposition, bow down. You are single-handedly outnumbered.” Other images tout the rifle’s “military-proven performance” and call it “the ultimate combat weapons system.”

With that type of marketing, the Sandy Hook families claim, “The Bushmaster Defendants attract buyers by extolling the militaristic and assaultive qualities of their AR-15 rifles.” The complaint alleges that while the weapon is suitable for the military and for law enforcement—where it’s used for combat and limited police purposes—in civilian hands, the high-caliber, rapid-fire rifles are essentially killing machines.

One law professor sees those claims as having some chance of success—if not in court then at least in shaping public opinion. John Culhane of Widener University’s Delaware Law School, a longtime advocate for using litigation to reform gun-industry practices, says the plaintiffs deserve points for creativity by trying to find a way around PLCAA through an attack on the industry’s selling of tactical firearms to civilians.

“It’s a long shot,” Culhane concedes, but the plaintiffs’ argument holds powerful potential if the suit manages to reveal the thinking behind the riflemaker’s marketing strategy for the military-grade firearms. Positioning the case as a contest between commercial exploitation and parents mourning murdered children puts enormous pressure on the industry, he says.

That pressure might be compounded by the enormous expansion of the tactical weapons and accessories market, which industry watchers believe is a chief engine of growth in the gun business. That’s largely due to the success of the AR-15, the semi-automatic civilian version of the U.S. military’s automatic M-16 rifle. The weapon is designed for endless tinkering, and has proven especially popular with young buyers more attuned to owning guns as a social pursuit, in contrast with more traditional markets in hunting and self-defense.

But the marketing-to-civilians argument can cut both ways. As Frank Miniter pointed out in the National Rifle Association magazine America’s 1st Freedom, the millions of civilian sales of AR-15s are evidence that the so-called “black rifle” has been embraced by the general public mainly without incident, a fact that would seem to undercut the Newtown plaintiff’s claim that the AR-15’s true utility is confined to criminal mayhem.

The Newtown lawsuit’s tug-of-war serves as a kind of replay of the debate that led to Congress’ passage of PLCAA in the first place.

Congress was prompted to pass the law by industry complaints that the firearms business might be sued out of existence by innovative legal attacks, brought at the time mostly by cities seeking to hold manufacturers or retailers liable for the costs of gun violence. PLCAA was meant to shut down those sorts of claims, which branded guns as a public nuisance under tort law, while preserving more traditional liability claims, says Georgia State law professor Timothy Lytton, who studies gun litigation.

One of those traditional theories that received protection under the statute—“probably the oldest theory in this litigation,” Lytton says—is called negligent entrustment: when a seller fails to make reasonable attempts to keep a gun out of the wrong hands. “The standard example of that,” Lytton says, “is handing a loaded firearm to a child or a visibly deranged person.”

Negligent entrustment was the central claim in the only gun-liability lawsuit to win a jury verdict since PLCAA’s passage. In that case, which was decided last October, a jury awarded nearly $6 million to two police officers who were seriously injured with a handgun that a gun shop in Milwaukee, Wisconsin, sold to an obvious straw buyer in 2009.

No other negligent entrustment claim has made it that far under PLCAA, even when plaintiffs presented evidence that gun retailers knowingly sold guns to criminals or suicidal people. In a 2013 Missouri court decision, an Overland Park, Kansas, gun shop called The Bullet Hole won dismissal of a case where a man bought ammunition using a stolen credit card that he took from the neighbor he murdered, before going on a shooting spree in Kanas City. In another case, a gun shop in Odessa, Missouri, won dismissal of a negligent entrustment claim even though the family of a woman who committed suicide with a newly purchased gun had warned the store not to sell to her.

The string of dismissed cases makes the Newtown claim look all the more uncertain, since the negligent entrustment it alleges—that the marketing itself constitutes entrusting the weapons to the general public in an illegal manner—is far removed from any kind of dubious, one-on-one sale. As Bushmaster’s lawyers point out, the AR-15 that Lanza used to kill his victims at Sandy Hook was purchased legally by his mother more than two years before the shootings, according to the state’s investigation of the December 2012 massacre.

It’s another claim made by the plaintiffs’ lawyers that gives them at least a fighting chance, says Delaware Law School’s Culhane. This second argument also focuses on Bushmaster’s marketing. But it cites the marketing as a violation of Connecticut’s unfair trade practices act, which regulates irresponsible advertising. The advertising is deceptive and a violation of that state law, the plaintiffs argue, because it uses military imagery to entice the wrong sorts of consumers—civilians—to buy the product and then harm others with it.

That’s a fairly standard sort of deceptive advertising claim, Culhane says, regardless of whether it’s blocked by PLCAA or whether there’s any evidence that Lanza or his mother were influenced by Bushmaster ads. It’s common to hold manufacturers liable when “there’s such a mismatch between the marketing of the product and its reasonable use,” he says. “If you market them as military style weapons, you’re going to attract a certain class of consumer, perhaps, that will act on this information.”

A defendant isn’t protected under PLCAA if a plaintiff can prove a violation of an existing statute “applicable to the sale or marketing of guns,” as the law reads. The defense argues that means a gun-specific regulation, not a general statute like Connecticut’s advertising law.

The Sandy Hook plaintiffs’ attempts to evade PLCAA’s gun industry shield amount to an end-run around the law’s meaning, Bushmaster’s lawyers argue in court papers. They accuse the plaintiffs of applying “expansive and unrecognized” interpretations to PLCAA to mask the reality that they are pursuing the same sorts of claims that the law was designed to block. If the plaintiffs’ arguments prevail, the defense team states, their rationale “would swallow the statute’s overall purpose—to protect firearms sellers from claims arising from the criminal use of lawfully sold firearms.”

Those will be tough arguments to overcome, Culhane says. But one factor weighing in the plaintiffs’ favor is the fact that they managed to keep the case in state court, after spending much of last year beating back the defense’s insistence to try the case in the federal system.

While it’s common for a federal judge to interpret state law, or for a state judge to interpret federal law, the plaintiffs stand to gain by having Connecticut courts deciding how Connecticut’s deceptive trade practices law applies in this case, Culhane says. “Their interpretation of the reach of that statute would be the last word, potentially.”

If the Superior Court in Bridgeport, Connecticut rejects the defense’s motion to dismiss, then the case moves to the discovery phase, when the defense must turn over internal documents and expose executives to sworn interrogations. If that happens, Bushmaster has much to lose—even if the court later grants the defense a summary judgment or a jury finds in the gun company’s favor. Just entering discovery means the possibility that industry secrets will be brought to light.

Thanks to discovery in past cases, notes Lytton, “we know more about industry ideas and attitudes towards distribution and gun tracing than we did before.” In the Badger Guns case, for instance, Lytton points out that discovery turned up evidence of “extremely sloppy controls” over gun sales at the store. As a result, he says, “We know what abuses look like in a specific instance,” which helps lay the groundwork for future claims.

Judging from the towering pile of pleadings already generated in the case while it kicked around federal court, the lawsuit promises a legal slugfest for as long as it goes on. But it features a mismatch in gun-litigation experience, pitting the defense team’s James Vogts, a Chicago, Illinois lawyer with a long list of gun cases to his credit—including the recent Badger Guns case—against the plaintiffs’ Bridgeport firm of Koskoff Koskoff & Bieder, which is better known for representing the singer Michael Jackson’s family against his concert promoter and for a string of high-dollar medical-malpractice and personal injury cases.

That specialty, in fact, was the firm’s introduction to the Sandy Hook plaintiffs, when it represented some of the same families in a lawsuit to collect damages from Nancy Lanza’s homeowner’s insurance policy by claiming it was liable for her carelessness in making multiple guns accessible to her troubled son. The case settled last December for $1.5 million.

The city of Bridgeport itself is no newcomer to the issues in the Bushmaster suit. It was among those that sued the gun industry in the 1990s, in the wave of litigation that led to Congress’ passage of PLCAA. Among the city’s claims: Manufacturers and retailers violated Connecticut’s unfair trade practices act with advertising that falsely portrayed guns as a public-safety tool.

In 2001, the state’s high court tossed that lawsuit on grounds that the city lacked legal standing to bring the case. By then, the lead defendant, Smith & Wesson, had settled that and other cases, drawing scorn from its allies. One of the strongest denunciations came from the National Shooting Sports Foundation (NSSF), a gun-industry trade group, which accused Smith & Wesson of having “violated a trust with their customers and with the entire firearms industry” by surrendering. NSSF issued the statement from its office in Newtown, Connecticut.

This article appears courtesy of The Trace.