The Thaw trial was the first celebrity trial of the 20th century to utilise an insanity plea. As in other famous cases utilising this defence, psychiatry itself went on trial. With the Thaw fortune estimated at $40 million, the defence hired the best experts money could afford. The prosecution also had its cadre of noted psychiatrists, leading to a well-publicised "battle of the experts". The strategy for the defence, which consisted of raising doubt regarding Thaw's sanity and generating sympathy for him, proved moderately successful. In spite of a vague meaning for brain-storm and a strict legal test for mental responsibility, the jury was deadlocked and did not return a murder verdict. This book examines events leading to Thaw's shooting of White, and provides details of the trial and testimonies of the principal experts. Drawing largely from psychiatric literature of the early 1900s, Thaw's mental-health history is examined in the context of diagnostic concepts of the time. Possible interpretations in today's nomenclature are presented. Brain-storm, paranoia, and temporary insanity, and their evolutions in current terminology are discussed.