Enlisted in the U.S. Army on 7 September 1943 during World War II.
Gary Cooper paid Hayes $40,000 for the film rights to his novel "The Girl on the Via Flaminia" and another $10,000 to write the screenplay, but in the end he couldn't secure financing and the film was never made.
His novels enjoyed greater critical success in Britain than in the United States.
Began writing his first novel, while in Italy during World War II as part of a special service unit. Remained in Italy after the war and collaborated on several important neo-realist screenplays, notably with directors De Sica and Visconti.
Worked as a reporter for The Daily Mirror and The New York American, between 1932 and 1935.