Dexter is an American crime drama television series that aired on Showtime from October 1, 2006, to September 22, 2013. Set in Miami, the series centers on Dexter Morgan, a forensic technician specializing in blood spatter analysis for the fictional Miami Metro Police Department, who leads a secret parallel life as a vigilante serial killer, hunting down murderers who have not been adequately punished by the justice system due to corruption or legal technicalities.