OLATHE - A teenager impersonating a police officer spent the weekend startling other drivers, police say -- until he accidentally pulled the stunt on a real cop.

Patrol East officers received numerous reports Saturday about a driver with a loudspeaker, shouting instructions at other cars while waiting at intersections.

Officers had been unable to find the car, Sgt. Darren Chambers, said.

But just before midnight Saturday, an officer ending his shift was waiting at the stoplight at 21st and Woodlawn when another car pulled up slightly behind him in the next lane.

Over a loudspeaker he heard someone shout, "This is the police! Get out of your car and put your hands in the air!"

The officer, still in uniform, did get out. He arrested the surprised 15-year-old on suspicion of impersonating a police officer.