“The stories are interesting and the scientific approaches used to investigate them are fascinating.” ―The Paintsville Herald (Kentucky)   What constitutes historical truth is often subject to change based on new evidence. In this book, former detective Joe Nickell demonstrates the techniques used in solving some of the world’s most perplexing mysteries, such as the authenticity of Abraham Lincoln’s celebrated Bixby letter; the 1913 disappearance of writer and journalist Ambrose Bierce; and the apparent real-life model for a mysterious character in a novel by Nathaniel Hawthorne. Nickell also uses newly uncovered evidence to further investigate the identity of the Nazi war criminal known as “Ivan the Terrible.”   “A thoughtful, well-documented book in which the author shares with the reader techniques for solving historical riddles.” —Lexington Herald-Leader