Drug agents in Seminole County are investigating a long-practicing Sanford physician whose patients are trying to stop investigators from looking at their medical records. Agents with the City-County Investigative Bureau this fall searched the West First Street offices of Primary Care Physicians of Sanford and requested medical records held by the doctor, Vincent Mamone. It's not clear what he is under investigation for; authorities won't say. But the multi-agency investigative bureau focuses on drugs and organized crime.