When Gary L. Stewart set off to find his real biological father, he had no idea what was coming. Gary discovered that his real father was in fact the Zodiac Killer. The Zodiac Killler was a mad gunman that killed 4-6 innocent people in the late 60's. It was diffucilt for Gary to understand and comprehend all this.
Nearly 45 years later, Gary wrote his book, The Most Dangerous Animal of All: Searching for My Father. In the book, Gary describes how he tracked down his father and how he finally found out the truth.