WASHINGTON — The Supreme Court on Friday struck down a Trump-era ban on bump stocks, a gun accessory that allows semi-automatic weapons to fire rapidly like machine guns and was used in the deadliest mass shooting in modern U.S. history.

The high court found 6-3 the Trump administration did not follow federal law when it reversed course and banned bump stocks after a gunman in Las Vegas attacked a country music festival with assault rifles in 2017. He fired more than 1,000 rounds in the crowd in 11 minutes, leaving 60 people dead and injuring hundreds more.

A Texas gun shop owner challenged the ban, arguing the Justice Department wrongly classified the accessories as illegal machine guns.

The Biden administration said that the Bureau of Alcohol, Tobacco, Firearms and Explosives made the right choice for the accessories that can allow weapons to fire at a rate of hundreds of rounds a minute.