In a new memoir, "The Most Dangerous Animal of All," Gary L. Stewart claims that the infamous Zodiac killer was his father. The book was kept under wraps by publisher HarperCollins until its release Tuesday.
Authorities say the Zodiac killer murdered at least five people in Northern California in 1968 and '69, all the while taunting police and sending letters to the media. A suspect was never arrested.
Stewart, who lives in Louisiana with his family, was adopted. He says that more than a dozen years ago, after being contacted by his birth mother, he decided to track down his father and chronicled his search in a journal. Those notes formed the backbone of the book, co-written by author Susan Mustafa.
"Our lawyers felt it was legally sound," a HarperCollins publicist told New York magazine, which ran a story about the book on Monday.
It's not the first book to claim knowledge of the never-found killer. "The Zodiac Killer Cover Up," published in 2012, claimed that the killer was in his 90s and living in Northern California.
HarperCollins told New York magazine a police sketch of the Zodiac killer resembles a mug shot of Stewart's father, who was arrested for petty crimes in San Francisco.
A few years ago, San Francisco police took a partial DNA sample from the envelopes that contained the letters sent to media outlets. The genetic evidence seemed to point to Arthur Leigh Allen of Vallejo, who had previously been named as a suspect by police but never charged. Allen died in 1992.