Harry Morgan is Dexter's adoptive father. When alive, he was a
detective and highly-respected member of the Miami Police Department.
In the course of a high-stakes drug case, Harry began an illicit
relationship with Laura Moser, Dexter's biological mother, to gather
information and evidence on the drug lords in question. Laura was
discovered and made an example of; she and three others were executed
with chainsaws in a shipping container. Her sons, Brian and Dexter, were left in the container for several days[citation needed] until Harry and a police team recovered them. Harry adopted Dexter, while Brian was sent into foster care.
At first, Harry attempted to manage Dexter's violent urges by only
allowing him to kill animals, but he eventually came to the conclusion
that Dexter's pathology could not be repressed, only controlled: Harry decided to train the boy as a vigilante,
to hunt and kill murderers without leaving any clues. Dexter prized
these lessons as a means to fulfill his desires with his father's
approval, dubbing them the "Code of Harry". Harry's relationship with
his biological daughter Debra, meanwhile, was more complicated. She
craved her father's approval, but felt that he favored Dexter.
When Dexter was 19, Harry fell seriously ill and gave Dexter
"permission" to kill one of his nurses, who was intentionally poisoning
him with morphine. A year later, when Juan Rinez, a pimp who was murdering prostitutes, was released due to a faulty search warrant,
Harry lost his temper and told Dexter he was right in training him.
When Dexter killed Rinez, Harry was horrified by the way Dexter proudly
showed him the pimp's dismembered body. Harry committed suicide a few days later, by overdosing on his medication.