The suspect, 42-year-old Sadikouro Agoro, is accused of approaching the 17-year-old victim on a subway platform on August 21, 2013.
It happened at the 183rd Street and Jerome Avenue subway station.
Investigators say he exposed himself, then took off after the victim got on a train.
Agoro is described as a black male, approximately 6 feet tall and weighing 200 pounds. He was last seen wearing black work boots, blue jeans and a brown striped T-shirt.
Anyone with information in regards to this incident is asked to call Crime Stoppers at 1-800-577-TIPS (8477).
