A Long Island man who posed as a police officer to abduct two teenage girls was arrested on Thursday, police said.

Donald Cristiano Jr., 46, was charged with second-degree kidnapping, endangering the welfare of a child, first-degree criminal impersonation and luring a child, Suffolk County cops said.

The charges stem from a harrowing incident on Tuesday, when a 14-year-old and 16-year-old were lured into a car by a creep who attacked the younger girl before she managed to escape.

The teens were walking alone to the to the Lindenhurst Memorial Library at about 3:35 p.m. when Cristiano allegedly pulled up to them in a white sports utility vehicle.

The perv told them he was a cop and said he would give them a ride, police said.

Once they reached the library parking lot, Cristiano allegedly told the older girl to get out of the car because he needed to speak with the younger girl.

He then drove off to a nearby park with the 14-year-old and began touching her, cops said.

The brave teen was able to fight off the creep and fled to a home, where a resident called 911.

Cristiano, of Bay Shore, will be held in custody overnight and arraigned Friday at First District Court in Central Islip. It was unclear whether he had an attorney.