Marino was an Italian immigrant who became a member of the Milwaukee crime family under Vito Guardalabene. Marino stated that his date of birth was August 23, 1913, although this was never substantiated. His father was reportedly a member of the mafia in Italy who died of tuberculosis. Marino was once arrested with Angelo Brondo for passing counterfeit silver certificates for which he was convicted and served one year in prison. Marino was also convicted of reckless driving in 1933 and arrested for rape in 1929 and for a holdup in 1931. In 1946, he was convicted of running a gambling house. Santo was related to Angelo Marino, a future boss of the San Jose crime family, Salvatore "Sam" Marino, Angelo's father, was his cousin. His relationship to powerful Milwaukee mafia boss Frank Balistrie