Meet Gary L. Stewart, The Man At The Center Of FX’s New Zodiac Killer Docuseries

If you think your parents can be weird sometimes, try living with the feeling that your dad is the infamous Zodiac Killer. That’s definitely not a situation you ever want to find yourself in, but it’s very much the reality Gary L. Stewart, from FX's The Most Dangerous Animal of All, has lived with for most of his adult life. What started off as just trying to find his biological father led Steward down a rabbit hole drawing conclusions that his dad, Earl Van Best Jr., was the Zodiac Killer, something he documents in his book The Most Dangerous Animal of All (written alongside journalist Susan Mustafa). 

During the late 1960s and into the early 1970s, the Zodiac Killer terrorized Northern California, killing at least five people, but it’s suspected (and the Zodiac killer claimed) that they had killed more — possibly upwards of 30. Though the Zodiac Killer has never actually been identified (the case was declared inactive in 2004, and reopened in 2007 in San Francisco), over the years detectives and sleuths have tried to narrow down the suspects. There are almost a dozen of them, with the most notable being Arthur Leigh Allen, though his supposed involvement has never been proven.

And while simply trying to find his real dad, Stewart found himself swept into the mystery. He believed he had found his real dad, and that his real dad was a murderer. In 2014 he published The Most Dangerous Animal of All, which FX has now adapted into a documentary chronicling Stewart’s search for answers. Before you dive into the doc, here’s what you need to know about Stewart and his book. 

Stewart hails from Baton Rouge, Louisiana, and currently works as an electrical engineer and vice president of Delta Tech Service of Louisiana. As a child, he was given up for adoption and had no contact with his birth parents until his late 30s. It was then that his birth mother, Judy Gilford, reached out to him. 

She told Stewart that she had him when she was just a teenager and had run away from home with Earl Van Best Jr., a 27-year-old rare book dealer. The two abandoned their month-old son in Baton Rogue, leading Stewart to be adopted by another family. Learning all of this, Stewart decided to try and find his birth father, which led him to uncover Best. 

“[After speaking with my biological mother] I told her, you know what, I’ve got the best [adoptive] dad in the world in Baton Rouge and if my father took me from your arms and broke your heart like that I don’t think I want to know this guy,” Stewart told the Baton Rouge Genealogical and Historical Society in April 2019. “That was the end of my story. Until the next day when I was flying back to Baton Rouge and I had time to think about it. I decided I wanted to hear his side of the story.”

Well, “his side of the story” led Stewart to conclude that his dad was the Zodiac Killer. 

Before this, though, he simply started out trying to hunt down whatever he could find out about his dad, including records, his social security number, and even any mutual friends. However, even though he had some contact with the police (more on that later) to locate his father, the trail went cold. It wasn’t until he was watching an actual episode of A&E’s Cold Case Files about the Zodiac Killer that suddenly everything clicked and Stewart knew he had to dig deeper into this. 

Using what little information he had about his father, Stewart started to connect the dots as to who his father was; Van Best Jr. passed away in Mexico City in 1984. One of the most alarming pieces of evidence that Stewart uncovered was actually finding his dad’s name in one of the Zodiac Killer’s infamous cryptograms. 

The Zodiac Killer used to send cryptograms to the San Francisco Chronicle, claiming that anyone who could solve it would figure out his identity. In one of the cryptograms, Stewart found "EV," "Best," and "Jr." Stewart also claims that another expert found "Earl Van Best Junior" written backward in code. 

Additionally, Stewart claims that his mother resembles some of the female Zodiac victims, and his father was sending a message with their murders. Also, a reporter who targeted Van Best Jr. later received Zodiac letters and after Stewart’s mother got engaged to a police officer, another Zodiac letter was sent. Stewart also believes that some of his father’s handwriting (from his marriage certificate) matches the handwriting of the Zodiac killer. 

However, this is all a lot of circumstantial evidence with no actual hard proof. The San Francisco Police Department has never formally opened an investigation into this.

Stewart claims the SFPD department is embarrassed and that his theory being true would reveal major flaws in the department. He's alleged that that the department is performing a wild coverup to hide the Zodiac Killer’s identity and supposed missteps in the case. And in an almost absurd coincidence, Stewart’s biological mother married Rotea Gilford, one of the lead investigators on the case in San Francisco. Additionally, Stewart submitted to DNA testing and the police department supposedly never got back to him about the results, which only made him more suspicious.

Gilford’s relationship with Van Best Jr. was actually dubbed the “Ice Cream Romance” by the press because the two met at an ice cream parlor — while she was just 13 and he 27. The two started a relationship and married, but Gilford’s mother had the marriage annulled. That’s when they ran away, had Stewart, and later gave him up. Shortly after that, the two were apprehended and Van Best Jr. was arrested (Gilford was sent to a home for “wayward girls” while Van Best Jr. was charged with statutory rape). 

After Stewart and Gilford connected, she decided to help him locate his birth father. Considering that she had been married to a former San Francisco police officer, she reached out to the department for assistance. However, while they were willing to help at first, soon according to Stewart, everything went cold with the SFPD department telling him, “There are things in [Van Best Jr’s] file that we cannot and will not share with you. What’s in that file is so heinous, it will destroy you,” Stewart told The Advocate about the lack of information.

When The Most Dangerous Animal of All was first published, investigator John Hennessy told the San Francisco Gate, “We didn’t kiss him off. He was a very nice man, very well spoken. And I think he was sincere in his belief that his father was the Zodiac, but there wasn’t enough to move quickly on. And the reality is that without hard evidence it’s hard to prove a case.”

As for what Gilford believes, she has stated that she thinks Stewart’s claims are all “fiction” and that she “cannot imagine that Van could be capable of such violence.”

The Most Dangerous Animal of All is streaming in full on Hulu, via FX, now.