LA CROSSE, Wis. (WKBT) -

Charges are filed against the Grant County man who crashed a stolen car with a body in the trunk, but progression on his court case will be slowed.

The defense raised the issue of competency for 25-year-old Timmy Johnson, Jr. in court Thursday. He'll undergo an evaluation some time in the next three weeks.

Last week, Johnson led La Crosse police on a high-speed chase towards Holmen. According to the criminal complaint, Johnson reached speeds of 150 miles per hour before rear-ending another car on Highway 35, underneath the Highway 53 overpass. Police found the body of 79-year-old Merle Forbes in the trunk.

Forbes, who was previously reported as a missing and endangered person in Platteville, was pronounced dead at the scene. A preliminary autopsy showed assault to be the cause of death.

Johnson is charged with recklessly endangering the safety of three people involved in his crash and stealing Forbes' car.

He has not been charged with homicide at this time.