A Columbia University student charged with assault, sexual abuse and unlawful imprisonment last week has also allegedly attacked at least two other women. The women told authorities recently that Oliver Jovanovic, 30, attacked them in a manner similar to the way he is charged with attacking a 20-year-old Barnard Student. Prosecutors claims that Jovanovic brought the student to his apartment after dinner, tied her to a chair, undressed her and assaulted her with sex toys for almost a day. He repeatedly threaten to mutilate and kill her, Jeffrey Dahmer style. The two had met in an America Online Chat room. Jovanovic had an appointment to meet with another woman he met in cyberspace next week.