Taken from website: Legends of America
Thomas Gannon - Gannon was elected sheriff of Ellis County, Kansas on December 5, 1867 and quickly made a reputation for himself as a serious lawman, aggressively pursuing outlaws, often with the help of the local soldiers. However, his reign as a lawman would be a short one as early in April, 1868, he disappeared. Though what happened to him remains unknown, many of the time believed he had been murdered to prevent his testimony against an outlaw in an upcoming trial.