The case represents an ambitious effort by the families and relies on a novel strategy to find a route around sweeping protections provided by federal law to shield gun companies from litigation when their weapons are used in a crime. Supporters contend that if the case is brought before a jury, a trial could offer a glimpse into how the gun industry operates, and it could also offer a road map for the survivors and relatives of victims in other mass shootings as they pursue legal action.
Despite significant hurdles that stand in the way of its success, the case has nonetheless fueled an intense response from both sides of the gun debate, who see it as a potential threat to the companies’ legal protections.
The gun companies’ lawyers have argued that their clients were immune from the claims cited in the lawsuit, and they cautioned that agreeing with the families’ arguments would require amending the law or ignoring how it had been applied in the past.
The shooting “was a tragedy that cannot be forgotten,” James B. Vogts, a lawyer for Remington, told the judges. “But no matter how tragic, no matter how much we wish those children and their teachers were not lost and those damages not suffered, the law needs to be applied dispassionately.”
In 2005, Congress passed the Protection of Lawful Commerce in Arms Act, which blocks lawsuits by providing industrywide immunity from blame when a gun company’s product is used in a crime. Backers of the measure argued that it was an essential protection from predatory or politically driven lawsuits.
The law includes exceptions for sale and marketing practices that violate state or federal laws and instances of so-called negligent entrustment, in which a gun is carelessly given or sold to a person posing a high risk of misusing it.
Negligent entrustment has previously been used to sue gun sellers, but the Sandy Hook lawsuit seeks to broaden the scope to include a gun’s manufacturer.
It argues that the companies erred by entrusting an untrained civilian public with a weapon designed for maximizing fatalities on the battlefield, and that its advertising — relying on messages of combat dominance and hypermasculinity (“Consider your man card reissued”) — specifically appealed to disturbed young men who could be inclined to use the weapon to commit violence.
But the gun companies argued that the families’ lawsuit was exactly the kind of claim that gun companies were shielded from. (The state court judge reached much the same conclusion when she dismissed the suit.) If the federal law “doesn’t apply in this case,” asked Christopher Renzulli, a lawyer representing Camfour, the wholesaler, “well, then what case does it apply to?”
Justices asked about the weapon’s firepower and its use outside of combat during the roughly 90 minutes of oral arguments on Tuesday, which came a month before the shooting’s fifth anniversary and is set against the back drop of the recent deadly mass violence in Sutherland Springs, Tex., and Las Vegas.
Justice Richard N. Palmer referred to the families’ view of the weapon, saying it is “really a killing machine from their perspective.” The weapon used by Mr. Lanza was capable of carrying 30 rounds.
“What is a 30-round magazine used for?” Justice Palmer asked.
“You want to be able to fire your gun repeatedly without reloading,” Mr. Vogts replied. “It’s as simple as convenience in target shooting.”
Justice Andrew J. McDonald noted various slogans used for marketing, such as “forces of opposition bow down.”
“I mean, if it’s used for hunting or target practice,” he asked, “what’s the purpose of that ad?”
“Well, it’s also used in defense,” Mr. Vogts said. “In a home defense situation, if I felt the need in a firefight to defend myself and my family, I would certainly want to choose whatever firearm would force any opposition to bow down.”