"The Killer of Little Shepherds: A True Crime Story and the Birth of Forensic Science" is a non-fiction book written by Douglas Starr. It was published in 2010. The book explores the story of Joseph Vacher, a French serial killer who terrorized the French countryside in the late 19th century. Vacher's crimes involved the brutal murder of shepherds, children, and other innocent victims. Starr's book not only delves into the chilling details of Vacher's crimes but also examines the historical context of the time, including the state of forensic science and criminal investigation methods in the late 1800s. The book highlights the role of pioneering forensic scientists such as Dr. Alexandre Lacassagne, who played a crucial role in Vacher's eventual capture and conviction. Through meticulous research and vivid storytelling, Starr provides readers with a gripping account of one of France's most notorious killers and sheds light on the early days of forensic science and its impact on criminal justice. "The Killer of Little Shepherds" is praised for its blend of true crime narrative and historical analysis, offering readers a fascinating glimpse into the evolution of forensic techniques and their importance in solving crimes.