Suspects and Theories

Find out more about the suspects and theories below.

Key Suspects in the Zodiac Killer Case

The Zodiac Killer case has multiple potential suspects and persons of interest, with Arthur Leigh Allen suggested by Robert Graysmith’s book “Zodiac” based on circumstantial evidence. Allen had been interviewed by police since the early days of the Zodiac investigations and was the subject of search warrants. However, in 2010, all the evidence against Allen turned out to be negative. Gary Francis Poste, who died in 2018, was identified by the Case Breakers in 2021, citing forensic evidence and photos from his darkroom. However, law enforcement expressed skepticism and the FBI stated that there was no new information to report.

Other suspects were considered based on circumstantial evidence, fingerprint, handwriting analysis, and DNA testing. Ted Bundy, Edward Edwards, and Ted Kaczynski were investigated but eliminated as suspects through fingerprint and handwriting comparison or alibi. The Manson Family members were also ruled out as Zodiac suspects. The case highlights the complexity of the Zodiac Killer case, with multiple potential suspects and theories, but no definitive resolution as to the killer’s identity.

Investigative Theories

The Zodiac Killer case has sparked numerous investigative theories, with some suggesting multiple killers and others involving law enforcement, amateur sleuths, and true crime enthusiasts. Some prominent theories include the Multiple Killer Theory, which suggests that the Zodiac Killer was a group of people working together, based on geographical spread and eyewitness descriptions.The Zodiac’s Personal Life Theory suggests that clues to his identity could be found in his social interactions, family, or employment history.

Lastly, the Code-Cracking Theory suggests that enthusiasts and amateur cryptanalysts have dedicated significant efforts to decode the Zodiac’s unsolved ciphers, believing they may hold clues to the killer’s identity or motivations. Success in deciphering these codes could provide vital information.

The Zodiac killer claimed responsibility for 37 murders and sent taunting letters and cryptic messages to newspapers. The known victims of the Zodiac Killer include David Faraday and Betty Lou Jensen, Michael Mageau and Darlene Ferrin, Bryan Hartnell and Cecelia Shepard, and taxi driver Paul Stine. He’s also suspected in other cases, such as Donna Lass and Cheri Jo Bates, though the evidence linking him to these murders is less substantial. Find out more about this mystery killer below.