Palo Alto police are looking for fake cop who pulled over a teen bicyclist in Palo Alto last week and displayed either a stun gun or handgun from his car.

The impersonator reprimanded the teen -- a juvenile high school student-- for committing a traffic violation and drove away.

The Palo Alto Police Department's dispatch center received a call around 9: 06 p.m. on Sept. 5 about a suspicious circumstance that took place at 4:00 p.m. on Greer Road at Ivy Lane, police said. According to investigators, two teenage boys had been biking when they heard a voice on a PA system coming from a car behind them, ordering them to ride single file instead of side-by-side. They looked back and saw it was a car without any police markings, but complied anyway thinking it was an unmarked police car.

The two boys parted ways at Greer Road. The vehicle continued to follow one of them, ordering him to stop. When the student looked back, he saw "flashing police-style lights" coming from inside the car. He stopped his bicycle and the driver drove up next to him, showed him a badge and angrily lectured him about his riding habits.

According to police, the driver produced some sort of weapon -- which the student described as either a stun gun or a handgun -- and held it up pointed at the roof of his car so the student could see it. He then drove away.

The boy rode back home and told his parents what had happened.

"The kid is ok. He’s obviously shaken," Palo Alto Police Detective Sgt. Brian Philip said. "We’re obviously concerned because we have a stranger contacting a child representing himself as legitimate law enforcement. That’s a big deal."

The boy described the driver as being in his sixties with balding short gray hair, about 5'10' tall with a heavy build. He was wearing a light-blue collared shirt, similar to a uniform. His badge was silver but had a color design, with a green tree in the center. The suspect was driving a cream-colored four-door sedan with radio antennas on the roof, police said.

Anyone with information about the incident should call 650-329-2413. or email paloalto@tipnow.org.