WESTBROOK (AP) – A 16-year-old juvenile from Portland is believed to be the person who threw a rock from a Maine Turnpike overpass that cracked the windshield of a Maine State Police cruiser, injuring the trooper at the wheel, authorities said Monday.

Trooper Duane Doughty was driving north at about 10 p.m. when the rock came crashing down from the Brighton Avenue overpass, said Stephen McCausland, spokesman for the state Department of Public Safety.

Although the windshield did not shatter, Doughty was showered with glass fragments that struck his face and an eye. He was treated at Maine Medical Center for facial abrasions and was scheduled to see an eye specialist to determine the extent of any eye injuries, McCausland said.

The juvenile suspected of throwing the rock was in a group of three teenagers spotted walking near the overpass by troopers who responded quickly after Doughty radioed word of the incident, McCausland said.

After questioning the teens, the troopers were convinced that one of them was responsible, the spokesman said. “They had been returning from a nearby party where alcohol had been served to minors and that may have played a role,” he said. “That part of the investigation is ongoing as well.”

State police planned to consult with the Cumberland County District Attorney’s office to determine the appropriate charges to be filed.

McCausland said the rock thrower was not aiming at police and had no specific target.

“They did not know that it was a state police cruiser that had been struck,” he said.

Doughty, 36, of New Gloucester, is a former Lisbon police officer who has been with the state police for nine years. He could not be reached for comment.

McCausland said the safety threat posed by rocks thrown from overpasses cannot be overstated. “There have been horror stories around the state and the nation of serious consequences as a result of this kind of foolish prank,” he said. “We’re pleased that through quick action by fellow troopers, we were able to find out who was responsible.”