Police say a man impersonating an officer face charges after "affecting a traffic stop" on an actual detective while driving on a road in Florida.

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

McMahon stared Anderson down, pointed his finger at him and drove off.

First Coast News reports that during his more than 10 years of service the detective has arrested several police impersonators. But none had ever ordered him to stop his car.

McMahon is charged with impersonating an officer and unlawfully displaying blue lights.

He was released Tuesday after posting $5,500 in bail.