Question: What period of time was the serial killer that inspired the film Dirty Harry active?
Sentence (from "Dirty Harry (character)"): Inspector Harold Francis "Dirty Harry" Callahan is a fictional character in the "Dirty Harry" film series, encompassing "Dirty Harry" (1971), "Magnum Force" (1973), "The Enforcer" (1976), "Sudden Impact" (1983) and "The Dead Pool" (1988).
Relevant evidence: No