A new book alleges that not all the crimes attributed to Jack the Ripper were committed by the same person.

Dr Andrew Cook's new book, Jack the Ripper: Case Closed (sounds familiar) states that the Ripper letters were written by a journalist and that perhaps three of the murders were committed by one person. This is in line with the thinking of an assistance police surgeon at the time, Percy Clark, and Thomas Arnold, a policeman on the case.