GREENBELT, Md. – After a four-day trial, a federal jury returned a guilty verdict, convicting Thomas Emmanuel Williams, 52, of Laurel, Maryland, on 12 federal charges related to drug and firearms trafficking.Erek L. Barron, U.S. Attorney for the District of Maryland, announced the conviction with Special Agent in Charge Toni M. Crosby, Bureau of Alcohol, Tobacco,…