Almost exactly a year ago, a federal appeals court considered whether a Maryland law banning assault weapons was unconstitutional.

The law was passed in the aftermath of the Sandy Hook Elementary massacre, which left 20 first-graders and six adults dead after a man bearing an AR-15 style weapon stormed the Connecticut school.

“Nine terrified children ran from one of the classrooms when the gunman paused to reload, while two youngsters successfully hid in a restroom,” Judge Robert B. King of the U.S. Court of Appeals for the 4th Circuit, wrote in the majority opinion. “Another child was the other classroom’s sole survivor. In all, the gunman fired at least 155 rounds of ammunition within five minutes, shooting each of his victims multiple times.”

The court ruled that the ban on assault weapons like the one Adam Lanza used inside Sandy Hook that day — like the one that police say Nikolas Cruz has confessed to using inside Marjory Stoneman Douglas High School and that Omar Mateen used inside Orlando’s Pulse Nightclub and Stephen Paddock used from the Mandalay Bay in Las Vegas — was constitutional.