The Zodiac Killer–who gave himself the moniker in letters to police after claiming lives in northern California during the ’60s and ’70s–has fascinated the public for decades. The serial killer’s story is intriguing enough due to his taunting notes to police, which were accompanied with DNA-filled evidence to prove he was the real deal, but the fact that he escaped capture for all these years makes the case one that continues to captivate us. However, a new book that was kept secret until right before its release this week makes claims on the killer’s identity, and the author says he has proof.

Gary L. Stewart, who was abandoned in a Louisiana apartment building as an infant, began the search for his biological father ten years ago after making contact with his mother for the first time. He kept a journal during his research and said that his father, Earl Van Best Jr., passed away years ago. However, what he uncovered about the man is unsettling enough to intrigue Harper Collins Publishers and keep them from leaking press about it until now. Stewart wrote the book with journalist Susan Mustafa and discovered that his father was a man with a criminal record and a lot of unvented anger.

“Stewart and Mustafa construct a chilling psychological profile of Stewart’s father: as a boy with disturbing fixations, as a frustrated intellectual with pretensions to high culture, and as an inappropriate suitor and then jilted lover unable to process his rage,” Harper Collins said.

While Stewart claims to have evidence that his father was the famed killer and California police say they will take a look at whatever he’s uncovered, some are skeptical that the case has been solved. One of those people is one of only two individuals who survived the killer’s attacks, Bryan Hartnell. Hartnell and his girlfriend, Cecilia Shephard, were on a picnic when Zodiac attacked, stabbing the couple several times each. Shephard later died from her wounds, but not before she gave police a description of the man and his strange outfit: a black shirt and hood, with a white design on the shirt that looked like crosshairs.

“I somewhat follow the news, but there has been no time in the last 40+ years when someone was not (stirring) the pot,” Hartnell said.

Over the years, there have been at least 1,200 people to come forward with claims that they knew who the killer was and had evidence to prove it.

Image via Wikimedia Commons