Dexter is an American crime drama mystery television series that aired on Showtime from October 1, 2006, to present. Set in Miami, the series centers on Dexter Morgan, a forensic technician specializing in bloodstain pattern analysis for the fictional Miami Metro Police Department, who leads a secret parallel life as a vigilante serial killer, hunting down murderers who have slipped through the cracks of the justice system. The show's first season was derived from the novel Darkly Dreaming Dexter (2004), the first in a series of novels by Jeff Lindsay. It was adapted for television by James Manos Jr., who wrote the first episode. Subsequent seasons evolved independently of Lindsay's works.