Autopsies have revealed that a northern Illinois police officer died of blunt force trauma and a pickup driver was shot to death during an early morning traffic stop.

A spokeswoman for the city of Rockford says 30-year-old officer Jaimie Cox’s injuries may have been caused when the pickup crashed.

A separate autopsy shows that 49-year old Eddie Patterson Jr., is believed to have been shot by Cox. Patterson also was injured when the pickup crashed about 1 a.m. Sunday.

State police Sgt. Sam Thomas said Monday that Patterson’s driver’s license had been revoked and that Cox may have pulled him over after noticing license plates on the pickup “didn’t match the vehicle.”

Cox was found near the truck and pronounced dead at a hospital. Patterson’s body was inside the truck.

Visitation is scheduled from 3-9 p.m. on Friday at First Free Evangelical Church for Cox, the city of Rockford said in a news release. A police funeral service will start at 10 a.m. on Saturday at the church.