A motorist driving along Walkup Road near Prairie Ridge High School on Monday night noticed a dark colored car following closely behind.

The car appeared to be attempting to pass in the no-passing zone at about 9:40 p.m. in unincorporated Crystal Lake, McHenry County Sheriff Keith Nygren said in a press release.

But then, red and blue visor lights began flashing from the car, and the motorist believed he/ she was being pulled over by a police car.

"A male approached the victim’s vehicle in civilian clothes with no badge or identification," Nygren said in the release. "He yelled at the driver and quickly drove off without identifying himself, or the agency he represented."

The vehicle had no distinguishing markings to identify a police agency and had Illinois passenger plates. Sheriff’s deputies were unable to locate the vehicle or male driver.

The Sheriff’s Office wants to remind residents to always pull to the side of the road for police during a traffic stop in well lit and well traveled area when possible.

Officers not in uniform can provide a badge and identification during a traffic stop.

If drivers are ever concerned for their safety, they should contact 911 for police assistance, Nygren said.