Donald Rumbelow is a British true crime historian and former London police officer, born in 1939. He specializes in Victorian crime history, particularly the Jack the Ripper case. His seminal work, *The Complete Jack the Ripper* (1975), remains one of the most authoritative and frequently cited texts on the subject, praised for its meticulous research and balanced analysis. Drawing on his police experience and extensive archival work, Rumbelow brings methodical investigation techniques to historical mysteries. He has also written about other notable cases, including the Houndsditch Murders. His work is distinguished by its careful documentation, skeptical approach to sensational theories, and deep knowledge of Victorian London's criminal underworld.