Biography: Johann "Jack" Unterweger was an Austrian serial killer who murdered prostitutes in several countries. He was also a writer and journalist. First convicted of a 1974 murder, he was released in 1990 as an example of rehabilitation. He became a journalist and minor celebrity, but within months started killing again. He committed suicide following a conviction for several murders. Austrian psychiatrist Dr. Reinhard Haller diagnosed him with narcissistic personality disorder in 1994. Jack Unterweger's life and crimes is the subject of many biographies, documentaries and feature films.