Once a bright and upstanding district attorney of Gotham City, Harvey Dent is hideously scarred on the left side of his face after mob boss Sal Maroni throws acidic chemicals at him during a court trial. He subsequently goes insane and adopts the "Two-Face" persona, becoming a criminal obsessed with the number two, the concept of duality, and the conflict between good and evil. In later years, writers have portrayed Harvey Dent as having dissociative identity disorder, with Two-Face being an alter, which stemmed from the abuse he received from his father during his childhood.