“I promise that you’ve never read anything like The Most Dangerous Animal of All. Mesmerizing from the first page, the story includes a shattering surprise that will sear itself in your memory. Be prepared to read non-stop; this really is a book you won’t be able to put down.” —Jeff Guinn, author of Manson: The Life and Times of Charles Manson An explosive and historic  New York Times  bestseller of true crime and an emotionally powerful and revelatory memoir of a man whose ten-year search for his biological father leads to a chilling discovery: His father is one of the most notorious-and still at large-serial killers in America Soon after his birthmother contacted him for the first time at the age of thirty-nine, adoptee Gary L. Stewart decided to search for his biological father. It was a quest that would lead him to a horrifying truth and force him to reconsider everything he thought he knew about himself and his world. Written with award-winning author and journalist Susan D. Mustafa, The Most Dangerous Animal of All tells the story of Stewart’s decade-long hunt for his father following a complex trail of startling twists and connections. Combing through government records and news reports and through conversations with his father’s relatives and friends, Stewart turns up a host of clues, including forensic evidence, identifying his father as one of the most infamous and still-wanted serial killers in American history. “Very few books can be properly described as unique, and in particular there are very few new things under the True Crime sun. But I promise that you’ve never read anything like The Most Dangerous Animal of All by Gary L. Stewart with Susan Mustafa. The tale they tell is mesmerizing from the first page, and the story includes a shattering surprise that will sear itself in your memory. Just be prepared to read non-stop; as opposed to the usual overblown hype, this really is a book that you won’t be able to put down.” - Jeff Guinn, author of Manson: The Life and Times of Charles Manson “I promise that you’ve never read anything like The Most Dangerous Animal of All. Mesmerizing from the first page, the story includes a shattering surprise that will sear itself in your memory. Be prepared to read non-stop; this really is a book you won’t be able to put down.” - Jeff Guinn, author of Manson: The Life and Times of Charles Manson “Convincing....The author painstakingly pieces together over a decade’s worth of personal research and verbatim interviews with family, friends and law enforcement, then goes further to scrutinize and compare handwriting samples, police sketches and photographs, all bearing uncanny resemblances to recorded documentation from the Zodiac files.” - Kirkus “Stewart’s head-turning memoir, skillfully co-written by veteran true-crime journalist Mustafa, explores how the search for personal truth can sometimes unearth unexpected results….The author painstakingly pieces together over a decade’s worth of personal research and verbatim interviews with family, friends and law enforcement, then goes further to scrutinize and compare handwriting samples, police sketches and photographs, all bearing uncanny resemblances to recorded documentation from the Zodiac files…. Convincing.... The author’s family history offers chilling and credible correlations.” - Kirkus “A compelling work of true crime that makes a strong case for Best being responsible for the series of murders and horrifying threats that paralyzed San Francisco with fear in the late 1960s and early 1970s.” - Baton Rouge Advocate When Gary L. Stewart decided to search for his biological father at the age of thirty-nine, he never imagined his quest would lead him to a horrifying truth and force him to reconsider everything he thought he knew about himself. Written with award-winning author and journalist Susan Mustafa, The Most Dangerous Animal of All tells the story of Stewart's decade-long hunt. While combing through government records and news reports and tracking down relatives and friends, Stewart turns up a host of clues—including forensic evidence—that conclusively identifies his father as the Zodiac Killer, one of the most notorious and elusive serial murderers in history. At last, all the questions that have surrounded the case for almost fifty years are answered in this riveting narrative—a singular work of true crime at its finest as well as a sensational and powerful memoir. Gary L. Stewart is vice president of Delta Tech Service of Louisiana. More than a decade ago, Gary began writing a journal, chronicling every detail of his search for his father and his own identity. That journal served as the basis for The Most Dangerous Animal of All . Susan Mustafa is an award-winning author and journalist. She is the coauthor of Dismembered , written with Sue Israel, and Blood Bath , written with Special Prosecutor Tony Clayton and Sue Israel.