Peter Vronsky, PhD, is an investigative historian and a former film and television documentary producer. He is the author of Serial Killers: The Method and Madness of Monsters, Sons of Cain: A History of Serial Killers from the Stone Age to the Present, and Female Serial Killers: How and Why Women Become Monsters. His research and interviews have been featured in numerous books and television programs. He holds a PhD from the University of Toronto in the fields of criminal justice history and the history of espionage in international relations. A history instructor at Ryerson University in Toronto, he divides his time between Toronto, Canada, and Venice, Italy.