5 Zodiac Killer Theories You Should Know After Watching The Most Dangerous Animal of All

Earl Van Best, Jr. is the subject of FX's The Most Dangerous Animal of All, and it was his son, Gary Stewart, who worked with experts to compile the evidence against his birth father. Van Best was 27 when he met Stewart's mother, Judith Gilford, who was 14, at a San Francisco ice cream parlor. He married Gilford and she became pregnant with Stewart, but he was soon arrested for pedophilia, fraud, rape, drunk driving, and other charges, per The Chronicle.

Stewart, who was adopted, first noticed that his biological father had a strong likeness to the police sketch of the Zodiac killer. Additionally, he claims that Van Best was interested in cryptography like the killer, and the musicals of Gilbert and Sullivan (another favorite of the Zodiac). He also reportedly lived two blocks from the murder site of one of the Zodiac's victims, Paul Stine. His most compelling evidence came in the form of a handwriting analysis that allegedly matched Van Best's handwriting to the writing in the letters that were sent by the Zodiac to the San Francisco police and newspapers.

The evidence that Van Best could be the Zodiac is entirely circumstantial. And while Stewart stands by the handwriting analysis which is based on his parents' marriage certificate, a manager at the church where they were wed said that the priest filled out all of the documents, per The Chronicle.

Arthur Leigh Allen is perhaps the most famous suspect of all in the case thanks to former San Francisco Chronicle cartoonist Robert Graysmith's two books on the Zodiac. The 2007 movie Zodiac was based on Graysmith's books, and furthered the idea that Allen was the killer.

Allen, who died in 1992, was a convicted child molester from Vallejo where Michael Mageau and Darlene Ferrin were shot in 1969, per The Chronicle. The police questioned him twice during the Zodiac's active period due to reports that he talked about wanting to kill people. He also wore a Zodiac-brand watch, owned a gun of the same caliber as the one used in one of the Zodiac's shootings, and his friend, Don Cheney, reported that he called himself Zodiac before the name was used by the killer. Most disturbingly of all, on the day that Bryan Hartnell and Cecilia Shepard were stabbed at Lake Berryessa, Allen claimed he was scuba diving at the lake, and he returned home with a bloody knife in his car, as outlined in Graysmith's book.

Despite the compelling evidence against him, Allen reportedly didn't match the description given by witnesses to the police. His DNA also didn't match a 2002 test done on one of the envelopes sent by the Zodiac — although The Chronicle reported that the testing ultimately proved inconclusive making it harder to rule him out as suspect.

Retired police officer Harvey Hines believed that Lawrence "Kane" Kaye was the Zodiac. A car accident in 1962 resulted in brain damage that affected his behavior. His name, Kane, is also seen in one of the Zodiac's ciphers.

That alone makes for a flimsy case, but before the Zodiac's victim Darlene Ferrin was shot on July 4, 1969, her sister alleges that Kane had been following and harassing her. Furthermore, an investigation placed him near the locations of the Zodiac's murders at the times they occurred. In 1970, a woman named Kathleen Johns and her baby were picked up by a man who is believed to have been the Zodiac killer. During the harrowing ride, he allegedly threaten to murder Johns and toss the baby out of the window, but she was able to escape from the car with her child. Later, she picked Kane's photo out of a lineup and identified him as the man who was driving the car, as reported by BuzzFeed's investigative series Multiplayer.

There have been no reports that Kane's DNA has been tested against that of the Zodiac killer's. His handwriting was also not a match with the writing found on the letters.

The editor of a counter-culture newspaper in San Francisco, Richard Gaikowski allegedly invited a friend to commit violent acts with him. His paper also ran fictional stories that were disturbingly close to the real-life killings carried out by the Zodiac. In a 2014 interview with i09, Tom Voigt, who runs the leading site on the Zodiac killer, ZodiacKiller.com, shared that he's convinced that Gaikowski is the killer due to his nickname "GYKE" being found in the ciphers.

During an interview with the police in 1968, he claimed that he wasn't in town when the first murders attributed to the Zodiac were committed. Also, his DNA and fingerprints have not been tested against the DNA of the killer.

Much of the case against Sullivan boils down to how closely he matches descriptions of the Zodiac. He sported a buzz cut, glasses, and favored military style clothing, as well as boots like the one that left a print at the Lake Berryessa stabbings. There was also suspicion that he was connected to a Zodiac-esque murder that occurred in 1966. His coworkers at the college near where the body of Cheri Jo Bates was found said that he made them uncomfortable, and that he disappeared for days after the murder. A letter confessing to her murder was sent to The Press-Enterprise — before the Zodiac killings officially began, which rules out any copycat theories. Sullivan was explored as a suspect on the History Channel's The Hunt for the Zodiac Killer.

Compared to other suspects, there is relatively little known about Sullivan, and there's no record of him being called in for questioning in relation to the Zodiac killings.