Hmmmm...checked several news outlets for a description of the perps....nothing.
What about the surveillance cameras, in the immediate area?
The article features a photo of one victim, so the paper interviewed him. The article also indicates the paper interviewed the police. It's unlikely that neither the victim nor the police described the assailants.
The suspects, who remain at large, are described as black men between the ages of 15 and 25.
http://www.dailymail.co.uk/news/article-2839910/NYPD-hate-crimes-detectives-investigating-Orthodox-Jewish-man-beaten-spit-three-thugs-called-dirty-f-ing-Jew.html