Lawyer Thomas Demetrio, who is representing David Dao, the passenger who was violently dragged off an overbooked United Airlines flight, attends a press conference in Chicago, Illinois, the United States, on April 13, 2017. The passenger who was violently dragged off an overbooked United Airlines flight on Sunday night may file a lawsuit against the company, his lawyer Tom Demetrio said at a press conference Thursday. (Xinhua/Wang Ping)
