CASTLE ROCK, Colo. (CBS4) – Police in Castle Rock have issued a warning about a man who impersonated a police officer and attempted to sexually assault a woman.

A victim helped police create a sketch of the suspect.

The woman says the man tried to sexually assault her after he used red and blue lights in what looked like an unmarked car to pull her over in the Meadows neighborhood Tuesday night.

The suspect was described as a 6-foot-tall, 30-year-old white male with a thin build, short dark hair and a mustache. He was wearing blue tactical style pants with a jacket, a blue ball cap and protective shooting type glasses with yellow lenses. He was carrying an old police Maglite flashlight.

The victim told police the suspect was driving an older, black Ford Crown Victoria with spotlights on both sides and red and blue lights on the sun visors. It also had tinted windows.

Tips From The Castle Rock Police Department

• If you get pulled over, make sure it is a marked police vehicle. If it is not marked, the emergency lights should be built-in, rather than placed on the top of the car temporarily.
• Try to stop in a well-lit area or location where a lot of people are present.
• Turn on your emergency flashers, but do not turn off your car.
• Lock your door and only open your window a few inches until you are confident the officer is legitimate.
• Be polite, but express your concerns when in doubt. Most legitimate police officers will understand your concerns when properly explained.
• Look for a uniform, official department jacket and other equipment used by police.
• If the officer is in plain clothes, look for identifying clothing and equipment. If unsure, explain that you are unsure about the situation and ask to see a badge and identifying information.
• Call 911 from your cell phone. Tell the 911 dispatcher that you are concerned. If the dispatcher cannot confirm you are being pulled over by a legitimate police officer, stay on the line and drive to a safe place, such as the local police department.