The dark-haired actor used his haunted, sullen appearance and expressive deep-set eyes to create finely etched characterizations in five of the most acclaimed films of the 1970s. Cazale was memorable in his screen debut as Don Corleone's weak second son, Fredo, in France Ford Coppola's epic "The Godfather" (1972). He again worked for Coppola as Gene Hackman's assistant in surveillance in "The Conversation" (1974). In reprising his role as Fredo, now a Vegas lounge player with ambition who eventually betrays his brother, in "The Godfather, Part II" (also 1974), Cazale justly earned a Best Supporting Actor Oscar nomination. Perhaps his finest screen performance, though, was as Pacino's dim-witted, trigger-happy sidekick Sidney Lumet's superior bank heist comedy-drama "Dog Day Afternoon" (1975). With his long hair lankly framing a somewhat sweet face and his dark fixed eyes, Cazale's odd-ball Sal seamlessly played off Pacino's intensity, marking a high point in their collaborations. In his final screen appearance, Cazale had begun to show the effects of the cancer that would kill him, yet the actor was able to muster the requisite craft to create another memorable performance as a tightly-wound neurotic in Michael Cimino's "The Deer Hunter" (1978), which was released posthumously.