Between August and November 1888 five women were murdered in Whitechapel. The gruesome nature of their deaths caused panic and fear in the East End for months, and gave rise to the sobriquet which was to become shorthand for a serial killer - Jack the Ripper. For over a hundred years the identity of the killer has remained one of the world's greatest unsolved mysteries, and a wealth of theories have been posited which have pointed the finger at royalty, a barber, a doctor, a woman and an artist. Using her formidable range of forensic and technical skills, Patricia Cornwell has applied the rigorous discipline of twenty-first-century police investigation to the extant material, and here presents the hard evidence that the perpetrator of the Whitechapel murders was the world famous artist, Walter Sickert. By using techniques unknown in the late Victorian era, Patricia Cornwell has exposed Sickert as the author of the infamous Ripper letters to the Metropolitan Police.