Portrait of a Killer: Jack the Ripper—Case Closed (ISBN 0-425-19273-3) is a 2002 nonfiction book by crime novelist Patricia Cornwell that presents the theory that Walter Sickert, a German-British painter, was the 19th-century serial killer known as Jack the Ripper. Jean Overton Fuller, in her 1990 book Sickert and the Ripper Crimes, had maintained that Sickert was Jack the Ripper. Prior to that, Stephen Knight, in his 1976 book Jack the Ripper: The Final Solution, had maintained that Sickert had been forced to be an accomplice of the Ripper. Neither of these two books is mentioned in Cornwell's book. Cornwell's book was released to much controversy, especially within the British art world, where Sickert's work is admired, and also among "Ripperologists", who dispute her research methods and conclusions. Cornwell lashed back at these critics, claiming that, if she were a man or British, her theory would have been accepted. She has also made remarks indicating that those who study the Ripper case would rather have the mystery than its solution. Source: Wikipedia (en)