The White House has finalized a new federal rule that would regulate “ghost guns” more like regular guns. “Ghost guns” are firearms without serial numbers that are usually assembled from kits and often sold over the internet or created in 3D printers. The Justice Department reports about 6,000 such guns are recovered at crime scenes each year.

President Biden announced the new regulation Monday at the White House, where he was joined by Mia Tretta, a survivor of the Saugus High School shooting in Santa Clarita, California. In 2019, Tretta was shot in the stomach by a teenaged classmate in an attack that killed her best friend, 14-year-old Dominic Blackwell.

Mia Tretta: “Dominic had died, and so had another classmate, Gracie Anne Muehlberger, a 15-year-old girl with an infectious laugh. And a community was left shattered. I later learned that we had been shot by a 16-year-old student for reasons I will never know. He had brought his father’s weapon to school, a firearm I would come to know as a ghost gun. Ghost guns are untraceable, build-it-yourself firearms that look like a gun, shoot like a gun and kill like a gun, but have not been regulated like a gun.”

Biden’s new rule does not ban sales of ghost gun kits; instead, it would mandate serial numbers for weapons parts, as well as a background check for buyers.