The Justice Department concluded Friday that the federal government cannot criminally enforce a prohibition on licensed dealers selling handguns to law-abiding adults ages 18-20 because the restriction violates the Second Amendment.

The department’s Office of Legal Counsel said in a 49-page opinion that young adults are among the people whose right to keep and bear arms is protected by the Constitution. The finding means the DOJ cannot prosecute federally licensed dealers solely for selling handguns to otherwise eligible buyers in that age group.