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Crime News Murders

Who Is the Zodiac Killer? Here Are All Theories and Suspects in the Case

The unsolved murders that terrorized the Bay Area in the '60s have sparked profiles of the Zodiac Killer, dozens of suspects, and even conspiracy theories as to the murderer's identity. 

By Caitlin Schunn

One of America’s most famous unsolved murder cases haunts everyone to this day: The Zodiac Killer.

The killer was responsible for brutally murdering at least five people in California’s Bay Area in 1968 and 1969. More terrifying was the series of taunting, cryptic notes he sent to local newspapers, saying his identity could be found in ciphers he included.

But even with those notes, detectives were unable to uncover the truth. And while dozens of movies, documentaries, shows and books have been done on the murders with the intention of solving the crime, one question always remains: who is the Zodiac Killer?

RELATED: Letter From Self-Proclaimed 'Chinese Zodiac Killer' Sent To Upstate New York TV Stations

The Peacock documentary Myth of the Zodiac, premiering July 11, posits that the Zodiac Killer may not exist. But if it isn't a hoax, who could have done it? Keep reading to learn more about the theories surrounding the elusive figure...

The Profile of the Zodiac Killer

Two police sketches of the Zodiac killer

Because the murders did not fall under federal jurisdiction, the FBI never officially opened an investigation into the Zodiac Killer, according to the FBI website. Still, local law enforcement asked for the FBI’s help with handwriting analysis, cryptanalysis, and fingerprints. Many people have speculated on the profile of the killer, and his motives, including FBI criminal profiler, John Douglas, who’s written several books.

“What it [the ciphers] tells you about the person too is he’s obsessive compulsive,” Douglas said in an interview with Fox. “It would take hours and hours, and maybe days, to put this all together. But what he’s doing here is telling us how bright he is. He’s a lot smarter than the rest of the world.”

In a profile of the Zodiac Killer on the Crime Library website, Gregg McCrary also believed the Zodiac Killer’s letters shared something about his personality and intelligence.

“Among the most engaging aspects of the crimes for him was to be able to taunt the authorities from a superior perspective and to watch the police make fools of themselves,” McCrary said. “This often indicates a person who feels uncertain about his intelligence, so to reassure himself, he plays games with others. The Zodiac needed to think he was smarter than even the best detectives…people who knew him would have been familiar with his arrogance, as well as his shortcomings and insecurity.”

McCrary explored the Zodiac Killer’s motives further.

“Possible motives were to prove his superiority, get attention, control the investigation, create a terroristic climate, and relive the crimes via media reports,” McCrary said.

McCrary also pointed to the killer’s targeting of couples, which could mean he resented relationships.

“Going after couples, which he did three times, could indicate he was envious or jealous because he did not (or could not) have that type of relationship,” McCrary said.

Who Are the Zodiac Killer Suspects?

A letter from the Zodiac killer

The theories as to the identity of the Zodiac Killer are endless and are still coming out to this day. The theories were even a plot point in the Peacock series Based On A True Story, in which Kaley Cuoco's character, Ava Bartlett, discussed ideas with another character.

One theory discussed pertained to schoolteacher Arthur Leigh Allen, who was the only suspect ever publicly identified by law enforcement in the case. He was allegedly in the area during one of the murders, and in 1971, his friend told police he had allegedly expressed desires to kill and used the name Zodiac, according to the Daily Mail. However, his DNA was not a match for the partial DNA found on the stamps and envelopes the Zodiac Killer sent to the media, according to SFGate.com.

A volunteer group of cold case investigators called “Case Breakers” claimed Air Force veteran Gary Francis Poste was the real killer on its website. The group claims the Air Force veteran, who died in 2018, is the killer, based on a series of photographs dating back to 1963 that show forehead scars that the team thinks match marks made on a police sketch of the killer, according to their website. They also claim if you remove the letters of Gary Francis Poste’s name from one of the ciphers left by the Zodiac Killer, it reveals an alternate message.

RELATED: ‘I Am Not Afraid Of The Gas Chamber': Zodiac Killer's 1969 Cipher Has Finally Been Cracked

Richard Gaikowski is another popular Zodiac Killer suspect. Gaikowski lived in the Bay Area and was a newspaper reporter and editor at the time of the murders, according to Portland Monthly. In 1971, he was involuntarily committed to the Napa State Mental Hospital, which could explain why the killings stopped, according to those who believe the theory. A survivor of the attacks claimed the man who chased him and shot him was named Richard. And a victim’s sister said she recognized Gaikowski attending her brother’s funeral, according to Portland Monthly.

According to Oxygen.com reporting, several people have claimed over the years that their fathers were the Zodiac Killer, including Gary Stewart, who was featured in the FX series, The Most Dangerous Animal Of All. But a cipher expert in the series claimed thousands of different names could have been pulled out of the Zodiac Killer’s writings, not just Stewart’s father’s name.

Another theory points to the Unabomber as being the Zodiac Killer. Ted Kaczynski, who died in prison in June 2023, conducted a bombing campaign between 1978 and 1995, when he was arrested, according to Oxygen.com reporting. But some speculate Kaczynski lived in the Bay Area around the time of the Zodiac killings, and he also sent taunting letters to authorities as the Unabomber, much like the Zodiac Killer.

The theories also get far-fetched at times, with one rumor going around that Texas senator Ted Cruz is the Zodiac Killer — despite the fact that he was born two years after the killings started.

Why wasn't the Zodiac Killer ever caught?

One of the most gripping details of the Zodiac Killer case is that the murderer was never caught or identified. There’s a couple of things standing in the way of catching the killer, including DNA evidence. Although there is a possible DNA sample from a stamp stuck to one of the Zodiac Killer’s letters, it’s only a partial profile, according to SFGate.

“Because it’s not someone’s full DNA profile, it can’t be used to point to just one person,” the SFGate reported. “It can only rule someone in as a possibility or exclude them if it isn’t a match. It’s also possible the sample doesn’t belong to the Zodiac at all; it could be from a mail worker or any number of people who handled the letter over the years.”

Another problem — there’s no good description of what the killer looks like. Two people did survive attacks by the Zodiac Killer, but neither got a good look at the killer’s face as once he was wearing a mask, and the other time he shone a flashlight in the victim’s eyes, according to SFGate.com.

A cryptogram sent to the San Francisco Chronicle from the Zodiac Killer

Others speculate the Zodiac Killer stopped because he wasn’t obsessed with killing, he was obsessed with fame, a theory supported by FBI profiler John Douglas.

“If you would one day find him, find his room and go through his belongings, he would have every newspaper clipping, every story that’s ever been written about him,” Douglas said in an interview with Fox. “He would have his own personal diaries where he’s communicating to himself.”

Douglas argues there are cases where serial killers suddenly stop killing because they're able to relive that moment again and again.

“They would just go back into the fantasy,” Douglas said. “Just sit back in that La-Z-Boy chair and pull out your scrap book and think of your memories and what you did, that’s enough to get them through.”

To learn about the evidence supporting the theory that the Zodiac Killer doesn't even exist, check out Myth of the Zodiac Killer when it premieres on Peacock July 11.