ST. AUGUSTINE, Fla. -

A fake police officer is accused of signaling a real one to pull over on a road in St. Johns County.

Authorities say 20-year-old Matthew Michael Lee McMahon activated a red and blue light Monday while driving behind an unmarked County Sheriff's car. Detective Chance Anderson pulled over and was shocked to see an unknown face behind the wheel of the other car.

During his more than 10 years of service the detective has arrested several police impersonators. But none of them had ever ordered him to stop his car.

McMahon has also been charged for unlawfully displaying blue lights.

He was released Tuesday after he posted a $5,500 bail. It wasn't clear whether he's hired an attorney.