Authorities say a police officer and another man were both found dead at the scene of a single-vehicle crash in northern Illinois.

Rockford police Chief Dan O’Shea says the dead officer, 30-year-old Jaimie Cox, called for backup after making a traffic stop about 1 a.m. Sunday. Responding officers found Cox at the scene of the crash two blocks away, and he died at a hospital. Found dead inside the car was 49-year-old Eddie Patterson.

O’Shea says Cox became “entangled” with the car and fired a shot, but he declined to say how either man died or to provide additional details.

A city spokeswoman says Cox joined the Rockford department last December.

Illinois Republican Gov. Bruce Rauner says he’s “deeply saddened” by Cox’s death.