A prosecutor’s investigator who moonlights as a part-time police officer was arraigned Friday on an upgraded charge of leaving the scene of a fatal accident after a teenager he is accused of hitting with his county-owned vehicle died.

Peter Rauch, an investigator for the Onondaga County district attorney’s office, is accused of striking 18-year-old Seth Collier with the vehicle early Tuesday and then fleeing on foot. Rauch’s vehicle was found a block away in the parking lot of a private social club. His work identification and cellphone were found in the car.