An investigation into the man Scotland Yard thought (but couldn't prove) was Jack the Ripper. Dozens of theories have attempted to resolve the mystery of the identity of Jack the Ripper, the world's most famous serial killer. Ripperologist Robert House contends that we may have known the answer all along. The head of Scotland Yard's Criminal Investigation Department at the time of the murders thought Aaron Kozminski was guilty, but he lacked the legal proof to convict him. By exploring Kozminski's life, House builds a strong circumstantial case against him, showing not only that he had means, motive, and opportunity, but also that he fit the general profile of a serial killer as defined by the FBI today. The first book to explore the life of Aaron Kozminski, one of Scotland Yard's top suspects in the quest to identify Jack the Ripper, combines historical research and contemporary criminal profiling techniques to solve one of the most vexing criminal mysteries of all time. The book draws on a decade of research by the author, including trips to Poland and England to uncover Kozminski's past and details of the case. Includes a Foreword by Roy Hazelwood, a former FBI profiler and pioneer of profiling sexual predators. Features dozens of photographs and illustrations. Building a thorough and convincing case that completes the work begun by Scotland Yard more than a century ago, this book is essential reading for anyone who wants to know who really committed Jack the Ripper's heinous and unforgettable crimes.