Connecticut court ruled that families of schoolchildren killed in mass-shooting Sandy Hook 2012 can sue Remington, an American gun maker.
In a 5-4 vote, the US Supreme Court said the jurisdiction could proceed on the basis of state consumer protection laws.
Adam Lanza used the gun, which killed 27 people, including 20 elementary school students.
Control means the loss of an unusual law for an army firm in the case of mass shooting. 19659007] "The goal of families is always to give Remington a computed and profitable strategy to expand the AR-15 market and expand high-risk court users, all at the safety cost of Americans," said Josh Koshoff, a lawyer for families of victims.
"Today's decision is a critical step towards achieving that goal."
Remington did not immediately respond to a request from the BBC for comments.
Events were initially delayed following the filing of the bankruptcy firm last year
An initial suit against Remington was thrown out in 2016 and an appeal was received from the families to the highest court in the state last year. He is expected to go to the US Supreme Court.
Under US law, gun makers and dealers have legislated from legal liability if any of their weapons are used in criminal activity. Exceptions are made, however, in the case of harmful marketing.
"It seemed incredible that this type of industry would be protected," said David Wheeler, father of Sandy Hook's victim, in an interview with the Financial Times.
"It's hard not to watch this [ruling] and he thinks, maybe the states are swinging with her more sensible place."
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Lanza killed 20 students and six staff in the school. He spent his dead mother earlier. As police closed into school, he killed himself.