Police released the video of the man who they say he forcably touched the girl's backside as they boarded a No. 7 train at Queensboro Plaza last Firday morning.
The suspect is described as being around 5-foot-5 and was carrying a red messenger bag.
Anyone with information is asked to call Crime Stoppers at (800) 577-TIPS (8477). The public can also text their tips to CRIMES (274637), then enter TIP577.