It happened Sept. 26 in the Fordham Manor section of the borough.
According to police, the girl was walking down the sidewalk when she noticed the suspect taking photos of her from behind. He then ran up to her and grabbed her buttocks.
The man then fled the location.
Police describe the suspect as a Hispanic male, 5'5" who weighs approximately 160 pounds with dark hair and brown eyes. He was last seen wearing a white T-shirt, black pants and black sneakers.