Dexter Morgan, a Miami Metro Police Department blood spatter analyst, is living a double life. After his day job with the police department, Dexter moonlights as a serial killer, hunting and killing criminals who slip through the justice system. Dexter’s sister, Debra, a vice squad officer, pulls Dexter into her world when another serial killer is killing prostitutes and leaving their bloodless bodies dismembered in various locations around Miami.
The series blends drama and horror as it follows the day-to-day events in the life of Dexter Morgan, a forensic blood spatter analyst for the Miami Metro Police Department who also happens to be a serial killer. He was taught by his adoptive father, Harry, only to kill those “who deserve it”; mainly, other killers who have escaped the legal system or were never suspected in the first place. The series shows him balancing an everyday life with his secret identity, all while keeping up a facade of normalcy.
Dexter Morgan is introduced as a serial killer who kills other killers who have escaped from, or haven’t been found by the justice system. By day he is a blood spatter analyst who works for the Homicide Department of the Miami Metro Police. He is called to murder scenes involving mutilated bodies, but with no blood visible. The murderer, nicknamed the “Ice Truck Killer”, intrigues Dexter with this intricate methodology and a personal message in form of a mutilated doll. At the same time, Dexter’s sister Debra, a vice squad officer, tries to gain a transfer into the Homicide Department.
Dexter assists detectives Batista (David Zayas) and Doakes (Erik King) in investigating the murder of an officer, who was working undercover investigating drug baron Carlos Guerrero (Rudolf Martin). Doakes is personally involved in the case, since he was having an affair with the officer’s wife, who was also attacked. Meanwhile, Debra discovers the refrigerated truck in which the Ice Truck Killer dismembers his victims, and is promoted by her superior, Lieutenant Maria LaGuerta (Lauren Vélez), to the Homicide Department. Inside the truck, Debra, Batista and Dexter find a block of ice with five fingertips in it, left deliberately by the Ice Truck Killer.
After the discovery of another victim of the Ice Truck Killer at an ice rink, the missing guard, Tony Tucci, becomes a potential suspect. Rita receives an unpleasant visit from her ex-husband’s drug dealer, who confiscates her car, forcing her to take the bus to and from her job as a hotel receptionist. Dexter selects his next murder victim while having flashbacks of his first killing—a nurse who was caring for Dexter’s sick father, but was administering overdoses of medication to and slowly killing her patients. Elsewhere, Sergeant Doakes continues to harass Guerrero, as a group of renegade police officers decide to take matters involving Guerrero into their own hands.