Intro. Dexter is a forensic blood spatter analyst who works for the Miami-Metro Police Department. In his spare time, he is a vigilante serial killer who attacks other killers who have evaded the justice system. Dexter follows a code of ethics taught to him in childhood by his adoptive father, Harry Morgan, which he refers to as "The Code" or "The Harry Code" and is based on two principles: He can only kill people after finding conclusive evidence that they are guilty of murder, and he must not be caught. Dexter refers to his homicidal impulses as his "dark passenger" ;
Story: Dexter witnessed the brutal murder of his mother, Laura Moser, at the age of three, along with his older brother, Brian. The siblings were abandoned in a shipping container filled with blood and body parts for two days, Dexter was adopted by Harry and Doris Morgan was raised alongside her adoptive sister Debra who is younger than him.