The US Supreme Court has struck down a New York law restricting gun-carrying rights, in its most important judgement on guns in over a decade.
It expands gun rights amid a fierce national debate over the issue.
The decision, which jeopardises similar regulations in states like California and New Jersey, is expected to allow more people to carry guns legally.
About a quarter of Americans live in states that could be affected if their own rules are challenged.
The court found that a New York law requiring residents to prove “proper cause” to carry concealed firearms in public violates the US Constitution.
Justice Clarence Thomas, writing on behalf of the six conservative judges who make up the court’s majority, ruled that Americans have a right to carry “commonly used” firearms in public for personal defence.
The three liberal justices – Elena Kagan, Sonia Sotomayor and Stephen Breyer – dissented, meaning they disagreed with the majority opinion.
The decision comes amid political divisions over how to address gun violence, which were deepened by high-profile shootings at a primary school in Uvalde, Texas, and a grocery store in Buffalo, New York, last month.