For nearly 60 years the identity of the infamous 'Zodiac Killer' has remained a mystery.
Brutally killing in North California in the late 1960s, the serial murderer seemed to target lone men or young couple and quickly became a terrifying folk lore.
In chilling anonymous letter, the killer claimed he was responsible for the deaths of 37 people, although he has only ever been formally linked to five murders.
The missives were sent to regional newspapers and include horrifying threats of future murder sprees and even bombings.
Each of the letters included ciphers, with the serial killer insisting he was 'collecting' his victims to be used as slaves in the afterlife.
It was as late as 2020 that the final cipher used by the murderer was finally deciphered - but his identity still remained a mystery.
Just as suddenly as they started, the letters and cards to newsrooms stopped abruptly in 1974.
However, now journalist Thomas Colbert claims an FBI whistleblower has revealed to him that the main suspect was Gary Francis Poste, an Air Force veteran who died in 2018.
Poste had been linked to the case by a 'partial' DNA sample, according to Colbert.
Case Breakers, an organisation set up by Mr Colbert to crack cold cases, said in a statement: "The felon has been secretly listed as the Zodiac "suspect" in Headquarters' computers since 2016."
It seems the killer made a fatal mistake that gave away his identity in the months leading up to his death.
Poste gave away a huge haul of weapons, including guns and ammo, which contained his DNA.
In a statement, Case Breakers said: "Old associates of the housepainter/alleged serial killer claim that, a few years prior to Poste's 2018 death at 80, he had quietly given away his weapons, pistol parts, gunpowder, bullets and shell casings – more than a thousand, involving 25 different calibres – to his favourite locals."
Journalist Colbert now claims the boxes were sent to three separate labs, where they have been analysed.
Not only that, he insists there are six people who have all come forward to confess that Poste is the killer.
The FBI still insist the case is open and has not been solved.
