Man wanted for questioning in J train stabbing

A search is underway for the man behind a stabbing at a Bushwick subway stop. 
According to police, the victim was standing on a northbound J train platform at the Chauncey Street station when the suspect approached him, threatened his life and began stabbing him with an unknown object. 
Investigators released surveillance video taken Saturday night of a man who they describe as a person of interest wanted for questioning in the case. He's believed to be 5 feet 7 inches tall and 165 pounds. 
The victim suffered stab wounds to the back of his neck and back of his head, but was taken to the hospital in stable condition. 
Anyone with information on the assault should call Crime Stoppers at 1-800-577-TIPS