Van Best Jr. was a convicted pedophile with a history of predatory behavior, providing a psychological profile that Stewart argued fit the killer. The FX Docuseries and Debunking
After being contacted by his birth mother at age 39, Stewart began investigating his biological father, . Stewart claims that Van Best Jr. is the Zodiac Killer based on several pieces of circumstantial evidence: The Most Dangerous Animal of All
is a New York Times bestselling true-crime memoir by Gary L. Stewart and Susan Mustafa that presents a theory identifying the infamous Zodiac Killer . Published in 2014, the book chronicles Stewart's decade-long search for his biological father, which ultimately led him to believe his father was the elusive serial murderer. Core Premise and Theory Van Best Jr
Stewart noted a striking similarity between his father's mugshot and the 1969 police sketch of the Zodiac. Stewart claims that Van Best Jr
A handwriting expert initially suggested that Van Best Jr.'s writing on a marriage certificate matched the Zodiac's cryptic letters.
Stewart claimed to find his father's name, "Earl Van Best Jr.," hidden within the Zodiac’s famous unsolved cryptograms.