The 1960s San Francisco serial killer murdered five people – but has been linked to dozens of other murders
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)
For more than 50 years, the Zodiac Killer case has puzzled police and homicide detectives alike.
The serial killer murdered five people in and around the US city of San Francisco between 1968 and 1969.
At the time of these murders, the anonymous killer was taunting local police and the California public by writing coded letters to newspapers.
Since then, the Zodiac Killer has become something of a cultural icon – inspiring stories and characters in films, TV shows and novels.
In October 2021, a team of cold case investigators called Case Breakers claimed to have finally unmasked the killer as Gary Francis Poste.
So who is Gary Francis Poste, is he really the Zodiac Killer – and who were his alleged victims?
Who is Gary Francis Poste?
Gary Francis Poste was a US Air Force veteran who was from California.
He was 80 years old at the time of his death in August 2018.
Various media reports about Poste suggest that he was a violent man.
This relative accused Poste of being the Zodiac Killer and trying to kill him with a hammer.
When the Chronicle contacted the California police, they said there appeared to be no connection between Poste and the Zodiac Killer.
Poste’s former daughter-in-law Michelle Wynn also accused him of being the serial killer, according to the newspaper.
Ms Wynn said she moved away from California to be safe from Poste.
In January 2022, the US version of The Sun obtained a police report documenting how Poste pushed his then 74-year-old wife, Mary, against a wall and fractured his pelvis in four places in 2016.
The newspaper also revealed that the incident resulted in US authorities confining him to a psychiatric facility because it was determined he was too mentally incompetent to face a trial.
Had he gone before a jury, Poste could well have faced a prison sentence.
How was the Zodiac Killer “identified”?
Gary Francis Poste is the Zodiac Killer, according to Case Breakers – a group of more than 40 former police investigators, journalists and military intelligence officers.
The team said they based their case on forensic evidence, photographs found in Poste’s own darkroom and on some of the serial killer’s encrypted notes.
Forensic evidence proved Poste killed Cheri Jo Bates, the group claimed.
Bates was murdered in 1966 and linked to the Zodiac Killer – although the San Francisco Chronicle reported that this theory was disproved by local police.
Poste is also said to bear a resemblance to a 1969 police sketch of the Zodiac Killer, as he had similar scars on his forehead.
And it turned out that the letters of his name changed the meaning of the ciphers the serial killer had sent in letters to newspapers, suggesting that Poste was the killer.
However, according to the San Francisco Chronicle, the case breakers’ findings were dismissed by local police and the FBI.
The FBI’s San Francisco office told the newspaper that the Zodiac Killer case was open.
On November 20, 2021, the group claimed to have uncovered a “gold mine” of evidence in California.
In a statement, the team said they discovered Poste had given away weapons, including pistol parts, gunpowder and cartridge cases, to those who were close to him up until his death.
“Most of these strange ‘gifts’ have since remained untouched in basements and closets,” the Case Breakers claimed.
The team said it sent that evidence to private forensic labs in three US states.
It has also been alleged that Poste was once the leader of a group of young men whom he trained to become what the Case Breakers called “killing machines”.
The men, in their late teens and early 20s, are believed to have been known as “The Posse” and allegedly killed animals for fun The New York Post reports.
What Did the Zodiac Killer Do?
His victims were either shot or stabbed.
- David Faraday
- Betty Lou Jensen
- Darlene Ferrin
- Cecelia Shepard
- Paul Stin
Ferrin and Shepard’s partners – Michael Mageau and Bryan Hartnell – survived the attacks they faced.
All of the victims were young couples in their teens or early 20s – with the exception of Stine, who was a 29-year-old taxi driver.
The killer has been linked to several other cases of the common cold and in a letter claimed to have killed 37 people.
But that remains unproven.
The serial killer traced each murder with letters and cryptograms to local newspapers.
These sometimes included threats, including a plot to kill a busload of schoolchildren.
These letters all began with the phrase “This is the Zodiac speaking” – earning the nickname “Zodiac Killer” – and were typically signed with what appeared to be a crosshair of a weapon.
In 1970 the letters no longer appeared.
Speculations as to the identity of the killer have circulated since then.
Police have only officially named one suspect in the case – convicted child molester Arthur Leigh Allen.
Allen was singled out from a police lineup by one of the Zodiac Killer’s attempted victims and possessed a watch with the crosshairs symbol.
He reportedly partially confessed to the murders to a friend, but Allen died of a heart attack in 1992 before a trial could be instituted against him.
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.