ROCK COUNTY (CBS 58) -- Clinton police say they received a report Tuesday from a driver traveling westbound on County Highway X (Milwaukee Street) when an unmarked dark blue Ford Crown Victoria came up behind him. The driver saw police lights in the grill of the car and one on the dash.

When he pulled over, the driver stated a shorter, white male walked up to the passenger side. He was told he was being stopped for driving under the speed limit. 

Clinton police immediately began an investigation and determined the driver of the Crown Victoria was impersonating a police officer. The impersonator is described as being unshaven. He was last seen wearing a navy blue baseball cap and a blue police style uniform. He was also wearing what appeared to be a firearm in a holster on his left side.

If you see this vehicle or are attempted to be stopped by this vehicle, contact 911 immediately. Do not stop until a real officer in a marked squad is on scene.