GARLAND, Texas -- A Dallas County man fears he may have caught a police impersonator on his own dash cam while driving on I-635.

The man, who we'll call Mike, wishes to remain anonymous for fear of retribution from the driver. He and his wife were driving home separately the night of Sunday, Jan. 28, eastbound on I-635 approaching Centerville Road.

"I’m in the far right lane, and my wife is driving just a bit faster than me in the fast lane, and I notice a vehicle come up behind us, and turn red and blue lights on," said Mike.

He believes the car was a black BMW 6 series. That style of car and the flashing lights were what first made Mike wonder.

"Usually there would be lights coming from the back, but these were just in the front," he said.

His wife starts to pull over for what she thinks is a cop, and Mike hits the gas to catch up. Then, suddenly, the BMW’s driver turns off the lights, and quickly exits at Centerville Road. Mike thinks he knows why. In the far right lane is an out of service white and black colored Crown Victoria. He believes the driver was impersonating an officer, and that old squad car scared him off.

"My fear is he’s going to try to do it to somebody else," said Mike.

Garland Police told WFAA that quickly turning on the lights, then exiting the highway is very unlikely behavior for an undercover officer, and that there are no BMW’s in their fleet. They are looking in to what the couple witnessed. Their advice is to call 911 if you’re not sure the cop behind you is real.

Mike said he called police the second he got home to warn them of what he saw. This story is his warning to you.

"I want other people to be aware that car’s out there," said Mike.