He was perhaps best known for playing Mario, the Jake LaMotta trainer in the 1980 Martin Scorsese film Raging Bull.
[4] Gallo guest-starred in television programs including Peter Gunn, Police Woman, The Rockford Files, Wagon Train, Baretta, The Untouchables, Johnny Staccato and Columbo.
[2][4] He also appeared in films such as Too Late Blues, Aloha Bobby and Rose, Raging Bull, King Kong, A Woman Under the Influence, The Laughing Policeman and Capone.
[2][4] In 1976, Gallo co-starred in the new CBS drama television series Delvecchio, playing Sgt.
[4][5] In 1980, director Martin Scorsese cast Gallo in Raging Bull, for the role of Mario, Jake LaMotta's trainer, who shares the fighter's disgust after the thrown fight.