Federal authorities have filed drug and firearms charges against a Georgia sheriff’s deputy they say sold marijuana from his squad car to an undercover law enforcement agent. The FBI says Newton County sheriff’s Deputy Darrell Mathis showed up in his police car, dressed in his sheriff’s deputy uniform and wearing his official gun when he sold the agent. During his initial court appearance Friday, a lawyer was appointed to represent Mathis and he was granted $25,000 bond. The FBI statement says agents began investigating Mathis in April after two law enforcement officers said a confidential source told them he or she had seen a large amount of marijuana in Mathis’ Lithonia apartment during a social visit. They had the source set up the buys with the undercover officer.