DeSimone was born in 1909 in Pueblo, Colorado where his father Rosario was reportedly involved with the early Denver crime family organization. As a child his family moved to California. Desimone graduated from the University of Southern California Law School and became a lawyer in May 1933. Soon after he turned to a life in crime. DeSimone was involved in one of the botched assassination attempts on Mickey Cohen as a getaway driver. Jimmy "the weasel" Fratianno signaled DeSimone after a meeting with Cohen and DeSimone pulled up in a car with Frank Bompensiero, Leo Moceri, and another armed man. By the time they got past Cohen's bodyguards, Cohen had hidden in the bathrrom escaping harm, but two of his associates were injured and another, Harold "Hooky" Rothman, was killed. With a job as a