D.A.: Promotions make ‘strong leadership team even stronger’ Newly promoted deputy district attorneys are Michelle Frei (from left), Mark Conte, Renee Merion, and Thomas Ost-Prisco. Four Chester County assistant district attorneys have been promoted to deputy district attorneys, Chester County District Attorney Tom Hogan announced Friday. Hogan said the new deputies – Michelle Frei, Thomas Ost-Prisco,...