The Zodiac Killer, an infamous serial killer who was active in Northern California during the 1960s, had allegedly been identified on October 6, 2021. A task force led by former FBI agents originally made the claim, revealing the killer’s identity to be Gary Francis Poste, who died in 2018.

Years of forensic evidence revealed the two’s similarities, such as scars on Poste’s forehead that directly align to scars on the sketch of the Zodiac Killer.

The Zodiac Killer was responsible for up to six murders in the 1960s and 70s but claimed up to 37. He was also linked to several other cold cases, with two of his attempted victims surviving. He sent a series of letters to Bay Area newspapers, filled with ciphers and cryptograms and always beginning the letters with “This is the Zodiac speaking…” The killer coined his name from the symbol that he used to sign his letters with. He claimed the name himself in his letters before the media first began to use this alias.

The killer threatened mass killings and bombings if they were not printed. He claimed that he would reveal his identity if anyone managed to solve all of them, but the case remained unsolved until allegedly now. 51 years later, the deciphering of the letters sent by the Zodiac had aided in the reveal, according to the New York Post. For instance, the letters of Poste’s full name were removed to reveal an alternate message.

“So you’ve got to know Gary’s full name in order to decipher these anagrams,” said Jen Bucholtz, former army counterintelligence agent. “I just don’t think there’s any other way anybody would have figured it out.”

A photo of Gary Poste Francis was posted to Facebook by Glynn Barnes, a friend of Poste, nicknaming the man ‘Old Man Zodiac’ in his caption. This was enough proof for theorists to invest in him being the Zodiac Killer.

There are several other suspects in the Zodiac case; Earl Van Best, who directly matched the police sketch of the killer, and Ross Sullivan, a young man who was the police’s number one suspect due to his bizarre demeanor and behavior. Both cases were left open, as several more speculations surrounded who the Zodiac truly was.

Arthur Leigh Allen was one of the most prominent cases, having been dishonorably discharged from the Navy in 1958, and then having several convictions stemmed from disturbing advances on minors. This was the only person who was directly accused by law enforcement of being the Zodiac Killer, before Gary Poste Francis in 2021.

While the FBI personally has not confirmed Gary Francis Poste being the Zodiac Killer, all the evidence points to him. The case remains open, with other Zodiac experts disagreeing on the man’s identity.

“The FBI’s investigation into the Zodiac Killer remains open and unsolved,” FBI’s San Francisco field office said in a statement. “Due to the ongoing nature of the investigation, and out of respect for the victims and their families, we will not be providing further comment at this time.”

Poste can not be taken in for questioning, due to having died of natural causes in 2018, though the case has sped up, with new information coming out daily. It remains ongoing to this day.