Jason Michael Moss (February 3, 1975 – June 6, 2006) was an American attorney who specialized in criminal defense. He was best known as the author of The Last Victim: A True-Life Journey into the Mind of the Serial Killer (1999), a memoir about his exploration of the minds of incarcerated serial killers, which started as a research project in college. He corresponded and conducted personal interviews with several notorious killers. Struggling with depression, Moss took his own life in 2006. His book was adapted and produced as a film, Dear Mr. Gacy, released in 2010.