.Season 1
Dexter is traumatized from his childhood: He has to kill any emotions and the insatiable urge. This psychological disorder forces him to lead a double life.
In everyday life he is very anxious to appear normal and unremarkable. He works as a forensics at the Miami-Metro Police Department, where he is responsible for blood spatter analysis. His younger sister Debra also works with the police. It is the only person who feels for the Dexter something like affection. His girlfriend, Rita, who was beaten by her husband and lives separately from him is - as Dexter also beziehungsgestört -.
His dark side lives Dexter at night following the approach strictly to Harry's Code, the rules of his foster father Harry, Dexter's problem recognized early. In flashbacks, we are told how Harry teaches Dexter to fake emotions to lead a normal life. Also for the desire to kill Harry has a solution: Dexter to kill those who "deserve", that is killer, by the judiciary can not be sued. As a policeman, Harry knows in this matter from the best. Dexter learns from him to kill without leaving traces, but also countless rules designed to stop him, to kill indiscriminately or carelessly.
In the first season of Dexter hunts with his colleagues and his sister, a serial killer, the "refrigerated lorry-killers." This leaves its victims cut cleanly and completely drained of blood in their localities. Fascinated by the technology of the refrigerated lorry-Killers Dexter hopes to have found a kindred spirit, especially as the refrigerated lorry killer seems to know Dexter's hobby and made him the "game" in challenging him. In the course of the investigation is Dexter's sister Debra promoted and worked with Sgt Doakes in the investigation of the case. This proves to be difficult mutilated, until the night guard Tony Tucci found in a basement and the police will give you hints. While he is in the hospital to get dentures, it is maintained by Dr. Rudy Cooper. Debra learns to know him and falls in love with him. At the end of the season turns out that Rudy Cooper of refrigerated lorry killer and Dexter's brother. Dexter even kill him, after he tried to kill Debra. The police found no evidence that could lead to Dexter, because he made it look like a suicide.
