Authorities are looking for a stranger who put a 55-year-old straphanger in a headlock on a southbound D train in the middle of a May afternoon, then repeatedly rammed his head against the inside wall of the train, police say.



Cops say the suspect accused the victim, a man, of bumping into him on the train shortly after 3 p.m. on Tuesday, May 8, and punched him in the face. Then he grabbed his head and started throwing him into the train wall.



The suspect ran off the train at the East 167th Street stop and was last seen running north on Grand Concourse. The victim was taken to a hospital with numerous lacerations to his head, authorities say.



Anyone with information about the attack is asked to call Crime Stoppers at 1-800-577-TIPS.