HOPE TOWNSHIP, NJ (Warren County) — Authorities have identified the New Jersey state trooper involved in a fatal police chase earlier this month in Warren County. On Aug. 13, at around 10:19 a.m., a New Jersey State Trooper Christopher Bird began following a sport utility vehicle, driven by Sean Mamakas, 32, of Kempton, PA, on Interstate 80 eastbound in the area of milepost 11 to initiate a motor vehicle stop, according to the Warren County Prosecutor’s Office.