Police are asking for the public's help in finding a subway groper who then threatened a woman last month after both of them got off the train.

Cops say that on September 5th at about 8:30 a.m., a 34-year-old woman was on a southbound 4/5, when a man grabbed her buttocks while the train was going from the Brooklyn Bridge station to the Fulton Street station.

When the train got the Fulton Street, the woman got off the train and the man followed her and according to police, pulled out a knife and threatened her with it, before he fled the subway in an unknown direction.

Police say the man is about 30-years-old, was last seen wearing a black baseball cap, tan pants, a multi-colored shirt and multi-colored sneakers.

Anyone with information in regards to this incident is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS or for Spanish 1-888-57-PISTA (74782)
The public can also submit their tips by logging onto the Crime Stoppers Website or texting their tips to 274637(CRIMES) then enter TIP577.

If you see or experience sexual misconduct in the subway (this includes seeing a masturbator, being groped, being grinded on, etc.), you can report it to the MTA and police on this website. There's also a place for you to upload photos and/or video. Don't let the perverts win.