William John Burns (October 19, 1861 – April 14, 1932) was an American private investigator and law enforcement official. He was known as "America's Sherlock Holmes" and earned fame for having conducted private investigations into a number of notable incidents, such as clearing Leo Frank of the 1913 murder of Mary Phagan, and for investigating the deadly 1910 Los Angeles Times bombing conducted by members of the International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers. From August 22, 1921, to May 10, 1924, Burns served as the director of the Bureau of Investigation (BOI) (predecessor to the FBI).