Mario was born in 1933 to Sicilian immigrant parents. He had two brothers, Robert Riccobene, and an older half-brother, Harry Riccobene. During the 1950s he and Harry joined the Philadelphia crime family. They operated a loan-sharking and numbers racket and acted as Angelo Bruno's driver. Their crew had at least 35 members. From 1980 till 1983 Mario supplied mob associate Robert Rego with phenyl-2-propanone, a chemical needed to produce methamphetamine.