Supreme Court Rejects Mexico’s Suit Against U.S. Gun Manufacturers

In Smith & Wesson Brands v. Estados Unidos Mexicanos, 605 U.S. ____ (2025), the U.S. Supreme Court held that the Mexican government can’t hold gun manufacturers liable for aiding and abetting gun trafficking and drug cartels that have injured Mexico. According to the unanimous Court, because Mexico’s complaint did not plausibly allege that the gun manufacturers aided and abetted gun dealers’ unlawful sales of firearms to Mexican traffickers, the Protection of Lawful Commerce in Arms Act barred the suit.

Facts of the Case

The Protection of Lawful Commerce in Arms Act (PLCAA) bars certain lawsuits against manufacturers and sellers of firearms. The statute provides that a “qualified civil liability action . . . may not be brought in any Federal or State court,” and defines that term to include a “civil action or proceeding” against a firearms manufacturer or seller stemming from “the criminal or unlawful misuse” of a firearm by “a third party.”

However, PLCAA’s general bar on these suits has an exception, usually called the predicate exception, which applies to lawsuits in which the defendant manufacturer or seller “knowingly violated a State or Federal statute applicable to the sale or marketing” of firearms, and the “violation was a proximate cause of the harm for which relief is sought.”

The predicate violation PLCAA demands may come from aiding and abetting someone else’s firearms offense. PLCAA itself lists as examples two ways in which aiding and abetting qualifies—when a gun manufacturer (or seller) aids and abets another person in making a false statement about a gun sale’s legality or in making specified criminal sales.

More broadly, because federal law provides that whoever “aids [and] abets” a federal crime “is punishable as a principal,” a gun manufacturer that aids and abets a federal gun crime may itself commit a PLCAA predicate violation.

In this case, the Government of Mexico sued seven American gun manufacturers, alleging that the companies aided and abetted unlawful gun sales that routed firearms to Mexican drug cartels. The suit primarily alleged that the defendants failed to exercise “reasonable care” to prevent trafficking of their guns into Mexico, and so are responsible for the harms arising there from the weapons’ misuse. Because that theory implicates PLCAA’s general prohibition, the complaint relies on the predicate exception. It alleges that the manufacturers were “willful accessories” in unlawful gun sales by retail gun dealers, which in turn enabled Mexican criminals to acquire guns.

The complaint sets out three kinds of allegations relating to how the manufacturers aided and abetted retailers’ unlawful sales: The manufacturers allegedly (1) supply firearms to retail dealers whom they know illegally sell to Mexican gun traffickers; (2) have failed to impose the kind of controls on their distribution networks that would prevent illegal sales

to Mexican traffickers; and (3) make “design and marketing decisions” intended to stimulate cartel members’ demand for their products. The District Court dismissed the complaint, but the First Circuit reversed, finding Mexico had plausibly alleged that defendants aided and abetted illegal firearms sales.

Supreme Court’s Decision

The Supreme Court reversed. It held that because Mexico’s complaint does not plausibly allege that the defendant gun manufacturers aided and abetted gun dealers’ unlawful sales of firearms to Mexican traffickers, PLCAA bars the lawsuit.

“The predicate exception allows for accomplice liability only when a plaintiff makes a plausible allegation that a gun manufacturer ‘participate[d] in’ a firearms violation ‘as in something that [it] wishe[d] to bring about’ and sought to make succeed,” Justice Elena Kagan wrote on behalf of the unanimous Court. “Because Mexico’s complaint fails to do so, the defendant manufacturers retain their PLCAA-granted immunity.”

In reaching its decision, the Court first emphasized that federal aiding and abetting law reflects the view that a person may be responsible for a crime he has not personally carried out if he deliberately helps another complete its commission. The Court went on to note that its case law has further clarified that omissions, or inactions will rarely support liability. Moreover, routine and general activity that happens on occasion to assist crime—in essence, incidentally—is unlikely to count as aiding and abetting.

Applying this legal framework, the Court concluded that Mexico’s complaint does not plausibly allege that the defendant manufacturers aided and abetted gun dealers’ unlawful sales of firearms to Mexican traffickers. “We have little doubt that, as the complaint asserts, some such sales take place—and that the manufacturers know they do,” Justice Kagan wrote. “But still, Mexico has not adequately pleaded what it needs to: that the manufacturers ‘participate in’ those sales ‘as in something that [they] wish[] to bring about,’ and ‘seek by [their] action to make’ succeed.”

The Court next found that the types of allegations Mexico made failed to satisfy the demands of the PLCAA’s predicate exception, which only permits a suit to be brought against a gun manufacturer that has aided and abetted a firearms violation.

“Mexico’s suit closely resembles the ones Congress had in mind: It seeks to recover from American firearms manufacturers for the downstream damage Mexican cartel members wreak with their guns,” Justice Kagan wrote. “Of course, the law Congress wrote includes the predicate exception, which allows some suits falling within PLCAA’s general ban to proceed. But that exception, if Mexico’s suit fell within it, would swallow most of the rule.”