Some of the legendary gunmen of the Old West were lawmen, but more, like Billy the Kid and Jesse James, were outlaws. Tom Horn (1860-1903) was both. Lawman, soldier, hired gunman, detective, outlaw, and assassin, this darkly enigmatic figure has fascinated Americans ever since his death by hanging the day before his 43rd birthday. In this masterful historical biography, Larry Ball, a distinguished historian of western lawmen and outlaws, presents the definitive account of Horn's career.

Horn became a civilian in the Apache wars when he was still in his early 20s. He fought in the last major battle with the Apaches on US soil and chased the Indians into Mexico with General George Crook. He bragged about murdering renegades, and the brutality of his approach to law and order foreshadows his controversial career as a Pinkerton detective and his trial for murder in Wyoming. Having worked as a hired gun and a range detective in the years after the Johnson County War, he was eventually tried and hanged for killing a 14-year-old boy. Horn's guilt is still debated.

As a teller of tall tales, Horn burnished his own reputation throughout his life. In spite of his services as a civilian scout and packer, his behavior frightened even his lawless companions. Although some writers have tried to elevate him to the top rung of frontier gun wielders, questions still shadow Horn's reputation.