The owner of a methadone clinic in Rockland is charged with possessing cocaine. State drug agents arrested 42-year-old Angel Fuller-McMahan of Owls Head today along the New County Road in Rockland. Police say she runs the Turning Tide Methadone ClinicThe director of the Maine Drug Enforcement Agency says McMahan was arrested after agents observed her taking part in a drug deal in a private parking lot. We’re told agents seized about an ounce of cocaine hidden in McMahan’s pants, along with hypodermic needles.McMahan was taken to the Knox County Jail in Rockland and is free on bail She’s due in court next month. McMahan has a previous conviction of heroin possession.