The incident happened at a Barnes and Noble Bookstore in the children's section at the Palisades Center Mall in West Nyack.
The girl was sitting on a bench as her mother shopped nearby. The suspect is accused of approaching the girl from behind and performing a lewd act near the child.
The suspect appears to a Caucasian or Hispanic male in his late 20's, over 200 pounds, with a full beard and mustache.
He was wearing all black with a large imprinted area on the front of his shirt, and a baseball cap backwards.
The suspect may have left the scene in the passenger seat of a light green or similar colored van with out of state plates.
He appears to be the same suspect in a similar incident which involved an 8-year-old girl that took place at Bed, Bath and Beyond, also at the Palisades Center Mall, on December 21, 2013.
Anyone having information regarding this incident, or recognizing the suspect in the photos, is asked to call the Clarkstown Police Department at 845-639-5800 or the TIPS line at 1-877-639-6233.