WASHINGTON — The Supreme Court ruled Thursday that a 2005 law prevents Mexico from pursuing a lawsuit to hold U.S. gunmakers liable for $10 billion in damages for firearms that ended up in the hands of Mexican drug cartels.

The unanimous decision was based on a law known as the Protection of Lawful Commerce in Arms Act, which immunized gunmakers from most civil lawsuits stemming from “the criminal or unlawful misuse” of their weapons by others.

Although the law has exceptions, Justice Elena Kagan wrote for the majority, the allegations in Mexico’s lawsuit didn’t meet the standard. Kagan wrote that the law requires that a gunmaker violate a state or federal law in selling a firearm to be sued for the later misuse of that firearm.

Kagan said that in other cases the court has set a high standard for that kind of “predicate exception,” such as selling a high volume of restricted narcotics despite law enforcement warnings about potential illegal use.

“The kinds of allegations Mexico makes cannot satisfy the demands of the predicate exception,” Kagan wrote.

The Mexican government first filed the lawsuit in 2021, accusing Smith & Wesson, six other gunmakers and a distributor, of contributing to a pipeline of distributors and dealers who sold guns used in cartel violence in Mexico.

The Mexican government’s lawsuit argued that most gun violence in the country is committed using illegal firearms, primarily smuggled in from the United States. The Mexican government claimed that the gunmakers sell to distributors who then provide guns to dealers who sell to smugglers or straw purchasers.

The Mexican government argued that the gunmakers should have curtailed sales to some dealers and taken other measures to ensure that the guns did not end up being used in crimes.

Kagan wrote that those claims, along with others like advertising AR-15 rifles or marketing in Spanish, didn’t qualify for the sort of exception the 2005 law includes. Kagan wrote that those weapons are legal and advertising in Spanish can appeal to Hispanic American consumers.

“The manufacturers cannot be charged with assisting in criminal acts just because Mexican cartel members like those guns too,” Kagan wrote.

Initially a federal judge dismissed the lawsuit citing the 2005 law. A three-judge panel of the U.S. Court of Appeals for the 1st Circuit revived the case in 2024, finding that Mexico’s claims met the exception in the law. The gunmakers then appealed to the Supreme Court.

The decision sends the case back to the 1st Circuit to reconsider in light of the ruling that the 2005 law barred the claims.

Justices Clarence Thomas and Ketanji Brown Jackson filed separate concurring opinions. Thomas argued that the court should require a criminal conviction or similarly high standard to have a gunmaker face a suit under the 2005 law.

Jackson wrote that Mexico did not allege any specific practice by the gunmakers that went beyond industry norms, and that Congress did not intend to allow courts to regulate those practices through litigation.

Congress passed the law “to preserve the primacy of the political branches — both state and federal — in deciding which duties to impose on the firearms industry,” Jackson wrote.

The case is Smith & Wesson Brands v. Mexico.

©2025 CQ-Roll Call, Inc., All Rights Reserved. Visit cqrollcall.com. Distributed by Tribune Content Agency, LLC.