Courtney Ryley Cooper (1886-1940) was a publicist, journalist, U.S. Marine, historian, screenwriter, short story writer, novelist, non-fiction author, magazine writer, crime writer and crime expert. He was also an expert on circuses, at the time of his death employed by Ringling Brothers, Barnum & Bailey Circus as chief publicist. He worked as a newspaper reporter for the Kansas City Star, New York World, Chicago Tribune and the Denver Post. His work at the Post led him to become the press agent for the Sells-Floto Circus (owned by the owners of the Post) in 1914. The Sells-Floto had absorbed the assets of William "Buffalo Bill" Cody's Wild West Show, including Buffalo Bill himself. Most of his non-fiction work focused on two subjects, the circus and crime; he was Annie Oakley's first biographer. His books Here's to Crime (1937), Ten-Thousand Public Enemies (1935) and Designs in Scarlet (1939) championed the cause of the young Federal Bureau of Investigation and made the case that corrupt local governments and police forces permitted lawlessness to flourish in many parts of the United States. He is widely believed to have ghostwritten the book Persons in Hiding (1938) as well as a number of magazine articles for Hoover.