This biography investigates the life and actions of Josef Mengele, the infamous SS physician at Auschwitz. Gerald L. Posner, an investigative journalist and author known for his work on historical figures and events, draws upon extensive research to detail Mengele's background, his role in Nazi atrocities, and his subsequent life as a fugitive. The book aims to provide a comprehensive account of his activities and the efforts to bring him to justice.

Gerald L. Posner's "Mengele" is recognized as a thorough and meticulously researched account of the infamous SS physician. Critics and historians have noted the book's detailed exploration of Mengele's life, from his early years to his notorious experiments at Auschwitz and his decades as a fugitive. The work is often cited for its comprehensive approach to documenting Mengele's crimes and the complex, often frustrating, international efforts to apprehend him. It stands as a significant contribution to the historical record of the Holocaust and Nazi war criminals.