A U.S. Navy officer has been sentenced to four years in prison and three years of supervised release for his role in purchasing handguns for the owner of a Chinese defense firm and hiding the relationship, according to the Justice Department (DOJ). Yang Fan, a lieutenant in the U.S. Navy, was convicted by a federal jury in November and sentenced on March 16. Yang was trained in anti-submarine warfare and previously worked in a patrol aircraft and as a tactics instructor at a Navy facility in Florida, the department said. He held a top-secret security clearance and was serving on active duty at the time of his crimes. “Fan Yang held a position of trust with the U.S. government working on anti-submarine warfare,” Assistant Attorney General for National Security Matthew Olsen said in a Wednesday statement. “Today, the court held him accountable for violating that trust by lying to the government …