Dirty Harry local and federal police committing offences and overstepping their authority by entrapment and obstruction of justice. Author McGilligan, argued that America needed a hero, a winner at a time when the authorities were losing the battle against crime. The box-office success of "Dirty Harry" led to the production of four sequels. In the 2007 film "Zodiac", also set in San Francisco and inspired by the Zodiac Killer, cartoonist Robert Graysmith approaches police detective Dave Toschi at the cinema, where he is watching "Dirty Harry" with his wife. When Graysmith tells Toschi he is going to catch the Zodiac killer, Toschi
Dirty Harry far a free, democratic society can go to protect itself. The original draft ended with a police sniper, instead of Callahan, shooting Scorpio. Another earlier version of the story was set in Seattle, Washington. Four more drafts of the script were written. Although Dirty Harry is arguably Clint Eastwood's signature role, he was not a top contender for the part. The role of Harry Callahan was offered to John Wayne and Frank Sinatra, and later to Robert Mitchum, Steve McQueen, and Burt Lancaster. In his 1980 interview with "Playboy", George C. Scott claimed that he was initially offered the role,