Filinto Müller was the most despised police chief in Brazilian history and later a detested senator. Müller bore the brunt of many accusations of police wrongdoing owing to charges by yellow-journalist David Nasser. This volume examines the totality of Müller’s life and is the result of 11 years of research in which 66,704 documents, 500 newspapers clippings, and 165 visual items were examined. Numerous interviews were likewise conducted. This work has uncovered little archival evidence to substantiate direct charges against Müller. This book argues, however, that Müller was responsible for the invention of modern-day death squads, the first of their kind in the Americas.