The Case Breakers - a group of more than 40 former police investigators, journalists and military intelligence officers - claim to have identified Gary Francis Poste as the Zodiac Killer (image: Case Breakers)
Over the last five decades, the case of the Zodiac Killer has baffled police and armchair investigators alike.
The serial killer murdered five people in and around San Francisco between 1968 and 1969 and then taunted police by writing letters to newspapers.
In October 2021, a team of cold case investigators called the Case Breakers claimed to have identified the killer as Gary Francis Poste.
But the group’s assertion that Poste carried out the murders - and potentially dozens of others - more than 50 years ago have been disputed by the FBI.
So who is he, how was he identified as the Zodiac Killer - and what exactly has he been blamed for?
Here’s everything you need to know.
Who is Gary Francis Poste?
Gary Francis Poste was a US air force veteran who came from the Eastern area of California.
He was 80 years old at the time of his death in 2018.
According to the San Francisco Chronicle, the newspaper was contacted six years ago by a relative of Poste who said he lived in the town of Groveland.
This relative accused Poste of being the Zodiac Killer and of having tried to kill him with a hammer.
When the Chronicle contacted Californian police, they said there didn’t appear to be any connection between Poste and the Zodiac Killer.
Poste’s former daughter-in-law, Michelle Wynn, also accused him of being the serial killer, the paper said.
Ms Wynn said she had moved away from California to get away from threats posed by Poste.
How was the Zodiac Killer ‘identified’?
Gary Francis Poste is the Zodiac Killer, according to the Case Breakers - a group of more than 40 former police investigators, journalists and military intelligence officers.
The team said it had based its case on forensic evidence, photos found in Poste’s own darkroom and on some of the serial killer’s coded notes.
The forensic evidence proved Poste killed Cheri Jo Bates, the group claimed.
Bates was murdered in 1966 and has been connected by some to the Zodiac Killer - although the San Francisco Chronicle said this theory had been debunked by local police in August.
Poste was also said to bear a resemblance to a 1969 police sketch of the Zodiac Killer thanks to scars on his forehead.
And the letters of his name were found to change the meaning of the ciphers the serial killer had sent in letters to newspapers, and identified Poste as the killer.
However, the Case Breakers’ findings have been dismissed by local police and the FBI, according to the San Francisco Chronicle.
The San Francisco office of the FBI told the newspaper that the Zodiac Killer case remained open.
Sources close to the case said the Case Breakers’ evidence wasn’t watertight, while another warned the methods they used to crack the word puzzles could lead to a misinterpretation of them.
On Saturday 20 November, the group claimed to have discovered a “goldmine” of evidence in California.
In a statement, the team said it had discovered that Poste had given away weaponry, including pistol parts, gunpowder and shell casings, to those who were close to him in the lead up to his death.
“Most of these peculiar ‘gifts’ have remained in basements and closets, untouched, ever since,” the Case Breakers claimed.
The team said it had sent the haul of evidence to private forensic labs in three US states.
What did the zodiac killer do?
The Zodiac Killer captured the world’s attention in the late 1960s after killing five people in the San Francisco area and sending taunting follow-up letters to local newspapers.
The people who were murdered, either by being shot or stabbed by the man were: David Faraday, Betty Lou Jensen, Darlene Ferrin, Cecelia Shepard and Paul Stine.
Ferrin and Shepard’s partners - Michael Mageau and Bryan Hartnell - survived.
All the victims were young couples in their teens or early twenties - apart from Stine who was a 29-year-old taxi driver.
The killer has been linked to several other cold cases and claimed in one letter to have killed 37 people. However, none of this has been proven.
The serial killer followed up each murder with letters and cryptograms to local newspapers. These sometimes contained threats, including a plot to kill a busload of school children.
These letters all opened with the phrase “this is the Zodiac speaking” - spawning the Zodiac Killer moniker - and were typically signed off with what appeared to be the crosshairs of a gun.
The letters stopped appearing in 1970.
Speculation has been rife about the murderer’s identity ever since. The police have only officially named one suspect in the case - convicted child molester Arthur Leigh Allen.
Allen had been picked out of a police line-up by one of the Zodiac Killer’s attempted victims, wore the same boots as the killer as well as a watch carrying the Zodiac’s crosshairs symbol.
He also reportedly partially confessed his involvement in the murders to a friend.
But Allen died of a heart attack in 1992 before prosecutors could build a case to charge him.
There is also a long-standing joke that prominent Republican senator Ted Cruz is the murderer - a claim he played up to on Twitter by posting a meme.
The Zodiac Killer has spawned many pop culture references, including the 1971 Clint Eastwood film Dirty Harry and 2007 Jake Gyllenhaal, Mark Ruffalo, Robert Downey Jr. vehicle Zodiac.
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