Dirty Harry is known for giving us one of the most legendary cops in cinema history, but all that big-screen fun was inspired by the real-life case of the Zodiac Killer. One of a handful of films responsible for propelling iconic actor-turned-director Clint Eastwood to stardom, Dirty Harry has become a paragon of the action-thriller genre. Its gritty, neo-noir style was a hit with audiences in 1971 but many had no idea that both the killer and cop drew inspiration from an infamous string of real-world murders.
The Zodiac Killer terrorized Northern California with a series of murders in the late 1960s. Despite only being active for a few years, the killer’s cryptic imagery and taunting style captivated the public consciousness for decades to come. Dirty Harry, which kicked off Clint Eastwood’s Dirty Harry movie franchise, took inspiration from both the Zodiac himself and the real-world detective who pursued him. While the overall resemblance is loose, everything from the Zodiac’s name to the nature of their crimes had some influence on the film’s plot. Even the real-life serial killer’s bizarre aesthetic helped shape Dirty Harry’s wicked antagonist. If one compares the movie’s fictional killer to the real-life Zodiac, it’s crystal clear that this resemblance is more than just a coincidence. With all these similarities, how exactly did the movie adapt the Zodiac murders?
The film’s killer took many direct cues from the Zodiac Killer. Perhaps the most obvious connection is the name of the killer Clint Eastwood’s character chases being Scorpio. Moving from the name Zodiac to one based on a specific astrological sign is more of a hop than a leap. But the similarities between the real-life murderer and the movie serial killer don’t end there. Both are barbarous killers that appear to draw pleasure from playing a twisted game of cat and mouse with the police. At one point, Scorpio is depicted wearing a mask, a tactic famously employed by the real-world Zodiac during his crimes. Dirty Harry‘s Scorpio even shared his stomping ground with the Zodiac, with both operating around San Francisco.
The crimes themselves also took inspiration from the Zodiac. The real-life killer was notorious for taunting the police with a series of bizarre letters during his reign of horror. Scorpio copies this trait with a string of notes that appear to even imitate the Zodiac Killer’s handwriting. Dirty Harry‘s thrilling climax, wherein Scorpio hijacks a school bus, was inspired by a threat expressed in one of the serial killer’s real-life letters. Fortunately, this fantasy never played out in reality, but the similarity between the Zodiac Killer’s real-world crimes and those perpetrated by Scorpio bear an undeniable similarity.