The incident occurred about 11:30 p.m. Tuesday on Highway 11-W just west of Rogersville, possibly near the Marble Hall Road intersection.
The 22-year-old Hawkins County woman told investigators she was driving westbound when she noticed a white four-door sedan with a flashing blue light on the dash attempting to pull her over.
"She said it looked like an unmarked police car, and she thought she was being pulled over," Christian said. "The assailant walked to the side of her vehicle, brandished a handgun and removed her from the vehicle. The perpetrator took the victim to the side of the road, tore her clothing and raped her."
The suspect then told the victim to stay put until he was gone and left her on the side of the road, Christian said. When the man was gone, the victim drove to the nearby Lakeview Market, where the clerk called 911 for her.
The victim wasn't able to give police a good description of her assailant or his car.
"When he put the gun in her face that was her main focus, and she didn't get a good look at him," Christian said. "She said his vehicle looked like an unmarked police car, but she couldn't say if it was a Crown Victoria or an Impala, or what kind of car it was."
The victim was treated at Hawkins County Memorial Hospital. Christian said she was very upset and was unable to provide investigators with much information, but they hoped she could remember more later.
Christian is asking anyone who might have passed by that section of 11-W around 11:30 p.m. Tuesday and noticed the two vehicles stopped on the shoulder of the westbound lane to contact his office at 272-4848. He said hopefully the fact that the phony police car was using a single blue dash light might stick out in someone's mind.
Any details, no matter how small or seemingly insignificant, might be helpful in tracking this person down.
Christian noted that within his department unmarked detective's cars rarely make traffic stops. When detectives do stop a car it's usually related to an investigation, and they don't approach the vehicle until backup arrives.
As a precaution, Christian said that for the time being if a person is stopped in Hawkins County and the motorist feels suspicious about the legitimacy of the police car, that motorist can continue on at a pace slightly slower than the speed limit and stop in a public location.
"We're just asking that they flip on their right turn signal to acknowledge to the officer they intend to stop, and they can continue on to a store or some other location where there are other people around before stopping," Christian said.