It happened on a northbound J train last Tuesday around 2:33 a.m.
The attacker was last seen at the subway station at Lorimer Street and Broadway.
The victim was stabbed in his neck and back.
He was taken to NYC Health & Hospitals/Woodhull where he was pronounced dead.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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