A Newton man is accused of groping a teenage girl on an airplane from Puerto Rico to Boston.

Jonathan Lefman, 46, of Newton, was arrested on Feb. 7 for abusive sexual contact while in the special aircraft jurisdiction of the United States, after a teenage female passenger told authorities he touched her inappropriately through the seat from behind her.

The assault allegedly happened on a flight from San Juan to Boston on Aug. 30.

The US Attorney’s office said in a statement that “it is alleged that Lefman intentionally worked his hand in between and through the area between the back and bottom of the seat directly in front of him, where the minor victim was seated, and touched the minor victim’s buttocks without her permission.”

The victim said she initially thought the man was stretching when she felt fingers touch her, but when she felt him again, she moved forward in her seat and took out her camera, with which she was able to video his fingers coming through.

She also said the man touched the backs of her feet with his feet. After exiting the plane, the victim showed the video to an adult family member she was traveling with, who confronted Lefman while at the airport. The adult family member also told Lefman’s wife, who was with their four minor children, that she should be concerned.

Lefman said he had been stretching and apologized. However, when later shown the video of the fingers by the FBI and Massachusetts State Police investigators, and asked if they were his, he said “I. . . I don’t know. I don’t know.” He said he remembered being confronted at the airport, but not why.

If convicted, Lefman could face up to two years in prison, one year of supervised release and a fine of $250,000.