Justice Department bans rapid-fire devices used in worst modern mass shooting

The Trump administration on Tuesday banned bump stocks, the rapid-fire attachment used to carry out the worst mass shooting in modern U.S. history.

The devices had been under scrutiny since a gunman killed 58 people and injured more than 800 from his perch in a Las Vegas casino in 2017. 

The stocks are plastic devices that allow semiautomatic weapons to function like machine guns. The Justice Department had for years concluded that they fell outside of laws banning machine guns. On Tuesday, the department reversed that position and issued a new rule that will prevent people from buying or owning them. 

Justice department officials believe as many as 520,000 of the devices have been sold nationwide since 2010. The main manufacturer of one brand in Texas stopped producing the device over the summer in anticipation of the ban.

A final rule banning the devices will be published Friday and people who own them will have 90 days to destroy them or turn them over to the ATF. Those who don't could face criminal penalties under federal gun laws.