Four people from knox county are facing drug charges after several maine drug enforcement agency busts.All four were on probation for prior convictions. 43-year-old Charles Harris of Rockland is charged with aggravated trafficking of cocaine and suboxone and possession of hydrocodone. Police say his charges were upgraded due to the act taking place in a drug free zone. Also arrested, 30-year-old Amy Ashley of Rockland. She’s facing cocaine trafficking charges as well. 24-year-old Jaclyn Erickson of Rockland is charged with aggravated cocaine trafficking and violation of bail. 27-year-old Jeremy Yeaton of thomaston faces charges of aggravated heroin trafficking.In addition, all four are charged with probation violations. DEA agents were assisted by Thomaston and Rockland police and the Knox county sheriff’s office.