South Dakota has become the first state in the nation to enact a law explicitly authorizing school employees to carry guns on the job. The New York Times reports that the law leaves it up to school districts to decide whether to allow armed teachers. Several other states already have provisions in their laws — or no legal restrictions — that make it possible for teachers to possess guns in the classroom. But South Dakota is the only known state with a statute that specifically authorizes teachers to possess a firearm in a K-12 school.