The Supreme Court has agreed to hear a second major gun case this term. On Friday the justices said they will review a Trump-era ban on bump stocks, a device the ATF says converts a semi-automatic weapon into a machine gun by firing multiple rounds with a single pull on the trigger. Machine guns have been banned under federal law since 1934. Supreme Court to consider whether domestic abusers can own guns Law Supreme Court to consider whether domestic abusers can own guns

The Trump administration reclassified the devices in 2018 after a mass shooting in Las Vegas in which the shooter used bump stocks on 14 guns and opened fire on a music festival, killing 60 people and wounding more than 400 in less than 10 minutes.

Prior to the shooting, the ATF had not classified bump stocks as illegal, but the shooting prompted a re-evaluation of how the devices work, and the agency ultimately banned them as illegal because a single pull of the finger causes the firing of multiple rounds; the ATF said the devices converted legal guns, like the semi-automatic AR-15, into illegal machine guns. A U.S. appeals court blocks a ban on rapid-fire 'bump stocks' Law A U.S. appeals court blocks a ban on rapid-fire 'bump stocks'

The rule went into effect in 2019 after the Supreme Court declined to block it. But in January of this year, the Fifth Circuit Court of Appeals, by a 13-to-3 vote ruled that the classification was illegal.