Former critic who turned out a handful of documentaries and contributed to the scripts of several films (notably by Guiseppe De Santis) before directing his first feature in 1961. Petri used stylish visuals and a knack for finely-paced storytelling to communicate his pointed social and political satire. His best films include "The Tenth Victim" (1965), a futuristic fantasy in which men and women are trained to kill each other for sport; "Investigation of a Citizen Above Suspicion" (1970), an Oscar-winning parable about a Fascist police chief; and "Lulu the Tool" (1972), a complex and absorbing account of a factory worker's political awakening.