 Gordon appeared twice in 1961 on ABC's "Adventures in Paradise", starring Gardner McKay; he was cast as Stevens in "Mr. Flotsam" and as Red Munce in "Adam San".His subsequent frequent, energetic performances as Capone-era mobster Frank "The Enforcer" Nitti in Desilu Productions' "The Untouchables" (1959–1963) led to his being typecast as an often darkly humorous 'heavy' for the rest of his career.Often stealing scenes from the stolid, humorless Eliot Ness, as portrayed by Robert Stack, his famous catch-phrase in "The Untouchables" (directed at the victims of Nitti's wrath) was "You're dead!"