Netflix viewers are currently devouring all three parts of the new true crime docuseries This Is the Zodiac Speaking. It examines the possibility that Arthur Leigh Allen — the only Zodiac suspect ever publicly named — could really be the man behind the killer moniker.

This is the latest effort from Hollywood to shed more light on the case of one of America’s most notorious serial killers. 50 years after the last confirmed Zodiac letter arrived at the office of the San Francisco Chronicle, we’re still talking about perhaps the most infamous unsolved crime spree in US history — and Hollywood can’t get enough of it.

The idea of the Zodiac Killer first came about in August 1969 when three California newspapers received almost identical, anonymous letters. They purported to be from the killer responsible for the shooting of a teenage couple in December 1968 and the attack on Darlene Ferrin and Michael Mageau in July 1969, in which Ferrin was killed and Mageau survived.

Watch: Trailer for Netflix documentary This is the Zodiac Speaking

The Zodiac continued to send messages to local newspapers, including a cipher that he said would reveal his identity when solved. It didn’t. Five murders in total have been officially attributed to the Zodiac while, in his final correspondence in 1974, he claimed to have killed 37 people.

Read more: Zodiac killer who terrorised San Francisco ‘identified’ by team of 40 cold case investigators (Sky News, 2 min read)

It didn’t take Hollywood long to express its fascination with an unknown serial killer active in California. The slasher movie The Zodiac Killer came out in 1971, while the killer was active, and director Tom Hanson has claimed in the years since that he was motivated to make the film because he thought that a killer as publicity-hungry as this wouldn’t be able to resist attending the premiere, where he could be caught.

On the more high-profile front, the same year featured the release of Clint Eastwood cop thriller Dirty Harry. Don Siegel’s film follows Harry Callahan’s attempts to track down a serial killer with the Zodiac-themed code name Scorpio. In that movie, Hollywood provided viewers with the catharsis of Harry gunning down the killer.

Numerous low-budget films focused on the Zodiac in subsequent years, while rock and heavy metal music often referenced the killer. But in 2007, David Fincher‘s meticulous thriller Zodiac provided perhaps the definitive pop culture take on the story. It follows the police investigation, with Mark Ruffalo as inspector Dave Toschi — one of the real-world inspirations for Dirty Harry — and Jake Gyllenhaal and Robert Downey Jr. as journalists looking to uncover Zodiac’s identity.

In true Fincher style, it’s a cold and engrossing thriller. It never glamourises or sensationalises the Zodiac story, laying out the horror of the killer’s crimes in stark and chilling fashion. The open-ended nature of the film really emphasises the frustration of the fact the Zodiac has continued to get away with his crimes.

Read more: David Fincher Shares Surprising ‘Zodiac’ Criticism and His Biggest Pet Peeve on Set (IndieWire, 3 min read)

This is why Hollywood just can’t stop telling stories about the Zodiac Killer. The true crime landscape absolutely loves an unsolved mystery and the vacuum of information is something numerous creatives and documentarians have relished the chance to fill. On top of that, the Zodiac’s love of puzzles and ciphers is catnip to the online sleuths and true crime enthusiasts who make hours and hours of podcasts and online videos.

There are plenty more oblique references to the Zodiac in pop culture. The Exorcist III features a serial killer called Gemini, for example. Even Fincher had previous with the Zodiac, having tried to cast Ned Beatty as the serial killer in Seven because of his perceived resemblance to the police sketch of the Zodiac. Beatty turned the role down and Kevin Spacey played the role instead.

Read more: Matt Reeves Reveals His Riddler’s Zodiac Killer Inspiration for The Batman (Nerdist, 2 min read)

In 2022, Paul Dano‘s pitch-black take on Riddler in comic book movie The Batman was heavily inspired by the Zodiac. Writer-director Matt Reeves spoke frequently about the connection and Dano told Yahoo Entertainment that it was a key touchpoint for the director, though less so for his performance.

“I know [the Zodiac connection] was important for Matt and it does say that the more real this is, the scarier it can be,” Dano said. “But it wasn’t a major influence on the actual performance. I don’t think you over-think or intellectualise about how big or small you can go.”

That brings us to This is the Zodiac Speaking and the latest take on the story of the Zodiac killer coming out of Hollywood. It seems clear that this is one cold case that is anything but frigid when it comes to the creative community of California. The enormous question mark continues to loom over the Bay Area and, as a result, Hollywood isn’t going to stop finding new angles to tell this story.

This is the Zodiac Speaking is streaming on Netflix UK now.