Who was the Zodiac Killer? There have been 9 suspects

Cameron Frew
Earl Van Best Jr, the Zodiac killer in the movie, and Arthur Leigh Allen

Netflix’s This is the Zodiac Killer re-examines the infamous unsolved case, raising Arthur Leigh Allen as the likeliest suspect – but nine men have been accused of being responsible for the murders.

In the late ’60s, five people were killed in the San Francisco Bay Area. Newspapers started to receive bizarre coded letters, threatening killing sprees and bombings if the outlets didn’t print them in full.

According to the man responsible, these deaths were just the tip of the iceberg. By the time of his last letter in 1974, he claimed to have taken the lives of 37 people. And yet, the Zodiac Killer case still hasn’t been solved.

Nearly six decades later, we’ve arrived at This is the Zodiac Speaking, a new Netflix true crime documentary focusing on Arthur Leigh Allen. I’m going to dig into his story, but remember, eight other people have been connected to the murders.

Arthur Leigh Allen

Zodiac suspect Arthur Leigh Allen sitting in a leather chair.

Arthur Leigh Allen remains the lead suspect in the Zodiac case, and he was the only person of interest named by the police.

Quick bit of background: Allen served in the US Navy for eight years, before he was honorably discharged in 1959. Nearly 10 years later, he was fired from his job as an elementary school teacher after accusations of sexual misconduct with students.

Police interviewed him after finding out he’d been seen in Lake Berrysea area around the same time Bryan Calvin Hartnell and Cecelia Ann Shepard were killed. According to him, he’d been scuba diving at the time.

Two years later, Allen’s friend Donald Cheney revealed that he’d once talked about wanting to kill people – and he’d even used the name Zodiac in conversation. Police interviewed him again (where he told officers they shouldn’t be known as “pigs”, a word the killer used to describe cops in a letter), and in 1972, they gained a search warrant for his home, where they found his watch – a Zodiac Watch to be exact, with the same logo used by the killer.

Zodiac suspect Arthur Leigh Allen with some kids.
Arthur Leigh Allen with the Seawater kids.

There was other circumstantial evidence: his handwriting contained similar grammatical errors to the Zodiac killer and his shoe size (10) was the same. In 1992, Michael Mageau, one of the Zodiac’s survivors, pointed to Allen’s photograph and said he was the killer, but a police officer who claimed to have seen him fleeing the scene of a murder alleged his face was “too round.”

However, police couldn’t build a strong enough case to prosecute Allen, and he died in 1992 at the age of 52 from arteriosclerotic heart disease.

In Netflix’s new docu-series, a family who knew Allen claims he confessed to the crimes and took their children to several of the Zodiac’s murder sites. It also points out how the murders stopped when Allen was held in custody for an unconnected crime (lewdness with a child).

Mark Ruffalo portrayed Dave Toschi, one of the investigating officers, in David Fincher’s 2007 movie. “As soon as that guy walked in the door, I knew it was him,” Toschi told the star, who added: “He was sure he had him, but he never had a solid piece of evidence. So he had to keep investigating every other lead.”

Earl Van Best Jr.

Earl Van Best Jr and a sketch of the Zodiac killer

According to The Most Dangerous Animal of All: Searching for My Father… and Finding the Zodiac Killer, a book published in 2014 by Gary Stewart and Susan Mustafa, Earl Van Best Jr. may have been responsible for the murders.

This was based on substantial, yet circumstantial evidence: “an uncanny police sketch, partial-fingerprint evidence, matched handwriting, encrypted messages in letters written by the Zodiac Killer, and partial DNA,” as per Vulture.

However, after Stewart’s theory was picked up by FX for a documentary series in 2020, holes started to appear. Experts discredited the links between Best’s handwriting and that of the killer’s, and while he was “angry” with the counter-evidence presented, he stuck to his theory.

“No matter what we threw at him, he’d say, ‘So we got the fingerprints wrong, we got the handwriting wrong, that doesn’t mean I’m wrong. I can only speculate that this has become such a part of his identity that it’s a hard pill to swallow,” Kief Davidson, the documentary’s director, said.

“I don’t think we’re ever going to know who the Zodiac Killer is. I would be surprised if Earl Van Best Jr. is the Zodiac, but I also wouldn’t be surprised if Earl Van Best Jr. was involved or had some connection to it.”

Gary Francis Poste

Gary Francis Poste and a sketch of the Zodiac killer

Gary Francis Poste was identified as a possible Zodiac suspect in 2021, with a group known as the Case Breakers alleging he murdered Cheri Jo Bates.

They believe Poste matches an earlier sketch of the Zodiac, particularly (as per the SF Chronicle) “with what appear to be identical forehead scars”, and anagrams supposedly revealed his name.

Bates, an 18-year-old college student, was killed in October 1966. It’s widely believed the Zodiac killer was responsible for her death, but echoing the police’s struggles to pin the crimes on Allen, this was never proven and her case remains unsolved (officially).

According to the group, the San Francisco Police Department and FBI had identified Poste as a suspect in 2016, and they even visited him in jail (he’d been charged with domestic violence). TV news anchor Dale Julin also claimed that Poste admitted to being the Zodiac when he interviewed him, but this couldn’t be verified.

“The Zodiac killer case remains open. We have no new information to share at the moment,” San Francisco’s FBI office said in a statement.

Giuseppe Bevilacqua

An image of Giuseppe Bevilacqua

Joseph “Giuseppe” Bevilacqua was identified as a possible Zodiac suspect by Francesco Amicone, an Italian journalist who’s been investigating the case for several years.

According to the reporter, Bevilacqua admitted he was not only the Zodiac but the Monster of Florence, a serial killer who killed 16 people in Italy between 1968 and 1985. However, Amicone didn’t record their conversation.

You can read a summary of Amicone’s thorough investigation, but here are two important details: Italian authorities dismissed their investigation into him in 2021, and Bevilacqua died a year later; and earlier this year, Amicone confirmed he’d sent Bevilacqua’s DNA profile to the FBI.

Lawrence Kane

A sketch of the Zodiac killer and a photo of Lawrence Kane

Lawrence Kane was identified by two people: Kathleen Johns, a survivor of the Zodiac, and the sister of Darlene Ferrin, the killer’s third confirmed victim.

Kane also worked at the Sahara Casino, the workplace of Donna Less, a suspected victim of the Zodiac. She disappeared without a trace in September 1970, and it wasn’t until 2023 that her skull was found and identified by DNA profilers. It’s unclear how she died.

In 2021, one of the Zodiac’s ciphers allegedly revealed the word “Kayr”, which may have been a typo of Kane, and the location of a school in South Lake Tahoe. however, this has been widely disputed.

Kane was diagnosed with impulse control order in 1962 after suffering brain injuries in an accident, and he died in 2010.

Paul Doerr

A photo of Paul Doerr and a sketch of the Zodiac killer

Paul Doerr was named as a Zodiac suspect in Jarrett Kobek’s 2022 book How to Find Zodiac.

According to the author, his weight and height lined up with witnesses’ statements about the killer, and his writing bore similarities to the Zodiac’s letters. His evidence, while circumstantial, was so convincing that Doerr’s daughter withdrew plans to sue Kobek.

Notably, Doerr was part of the Minutemen, a right-wing group that sent threatening letters to alleged communists with a symbol that looked similar to the Zodiac’s. Beyond that, he knew the same formula for an ANFO bomb and he hinted in a 1974 letter that he’d killed people. He was also interested in cryptography.

Doerr died in August 2007 at the age of 80. One researcher called him “the best Zodiac suspect that’s ever surfaced.”

Richard Gaikowski

Mugshots of Richard Gaikowski

Richard Gaikowski is considered the top suspect of Tom Voigt, a leading expert on the Zodiac killer.

He was a reporter in the Bay Area at the time of the murders, sometimes minutes away from the scenes of the crimes, but he was later committed to Napa State Mental Hospital in 1971. He died in 2004.

According to Voigt and other researchers, Gaikowski matched sketches of the Zodiac, and one of his victim’s sisters recognized him at their funeral. Gaikowski told the GBI he was out of the country at the time of the Lake Herman Road murders, even though he lost his passport, and authorities reportedly refused to compare DNA samples.

One of Gaikowski’s co-workers strongly believed he was the Zodiac, although they’ve been suspected to be a “conspiracy theorist with low credibility” and a “Zodiac kook.”

Richard Marshall

Richard Marshall

Richard Marshall lived in San Francisco in the late ’60s, close to the area where Paul Lee Stine was murdered.

As per History.com, neighbors and those who knew him said he was “peculiar” and spoke about finding “something much more exciting than sex”, and he also liked The Red Phantom, a movie cited by the Zodiac in a 1974 letter.

However, Marshall denied being the Zodiac in a 1989 interview, while acknowledging why he was considered a suspect. He died in a nursing home in 2008.

Ross Sullivan

Ross Sullivan and a sketch of the Zodiac killer

Ross Sullivan became a person of interest in the wake of Bates’ murder. He worked at the Riverside City College Library and disappeared for several days after her death, and his appearance and attire bore some resemblance to the sketch of the Zodiac.

In 1967, he moved to northern California and ended up being hospitalized for bipolar disorder and schizophrenia. He’s never been investigated by police, and he died in September 1977 aged 36 from a heart attack.

We’ve also listed all of the new true crime documentaries you can watch this month and the best serial killer documentaries available now.