The murder and mutilation of at least five prostitutes in the Whitechapel district of London in the fall of 1888 continues to fascinate students of true crime, largely because the perpetrator, Jack the Ripper, was never caught. The slayings have prompted dozens of books, and more than 100 identities for the killer have been suggested. The British authors?Evans is a police officer, Gainey a constabulary secretary?here argue that the killer was an American, a quack doctor named Francis Tumblety who at the time was suspected by Scotland Yard. Tumblety, a peddler of fake nostrums, had earlier been temporarily charged with complicity in the assassination of Abraham Lincoln. At the time of the Ripper murders, Tumblety, who was living in London and was out on bail for other charges, fled England and made his way back to the U.S., where he died in 1903. Evans and Gainey make a case as tenuous as most, theirs based on a contemporary letter written by the head of Scotland Yard's Special Branch, John Littlechild, who suspected Tumblety. Their book will interest only the most dedicated Ripperologists, who may also find merit in the grisly photos.