Earlier this year, a North Dakota sheriff was on the search for six missing cows. He turned up with a warrant at a family ranch, but was chased off by someone with a rifle, reports the Los Angeles Times. So he called in back-up, including a drone from Border Patrol, to search the family’s 3,000-acre ranch for the armed suspects. The drone used its sensors to find them and to determine they were unarmed. Police then arrested the family of six, marking the first known use of a drone to arrest U.S. citizens, reports the Times.