Berkeley, California, 1933. In a lab filled with curiosities--beakers, microscopes, Bunsen burners, and hundreds upon hundreds of books--sat an investigator who would go on to crack at least two thousand cases in his forty-year career. Known as the "American Sherlock Holmes," Edward Oscar Heinrich was one of America's greatest--and first--forensic scientists, with an uncanny knack for finding clues, establishing evidence, and deducing answers with a skill that seemed almost supernatural. Heinrich was one of the nation's first expert witnesses, working in a time when the turmoil of Prohibition led to sensationalized crime reporting and only a small, systematic study of evidence.