A male graduate student was robbed at around 11:15 p.m. last night, said a 12:54 a.m. email from Yale Police Department Chief Ronnell Higgins. Four males approached the student from behind when he was walking alone near the intersection of Park Street and Edgewood Avenue, just outside Pierson College. One of the males claimed to have a weapon, and the others robbed the student of his cell phone and head phones.