Debra Morgan (spelled Deborah in the novels) is a fictional character created by Jeff Lindsay for his Dexter book series.

In the television series based on Lindsay's books, she is mainly portrayed by Jennifer Carpenter in Dexter and New Blood, and as a younger version of herself by Molly Brown in Original Sin.

[1] She is the foster sister to Dexter Morgan (Michael C. Hall), whom Harry brought home after rescuing him from the scene of his mother's murder.

Debra was devastated when Harry died of an apparently accidental overdose of heart medication - unaware that he in fact committed suicide, unable to live with having trained Dexter to get away with murder.

Debra is characterized as smart and capable, yet unsure of herself, and so she relies upon Dexter's seemingly limitless expertise on murderers to solve difficult cases.

She works hard on the case, but her progress is hampered by her own insecurity and her antagonistic relationship with her commanding officer, Lieutenant Maria LaGuerta (Lauren Vélez).

However, FBI agent Frank Lundy (Keith Carradine) reassures her otherwise and they, mid-season, develop a romantic relationship, which ends when he is called away from Miami.

Debra is appalled when she finds out that Dexter is cheating on his girlfriend, Rita Bennett (Julie Benz), with his Narcotics Anonymous sponsor, Lila Tournay (Jaime Murray), of whom she is immediately suspicious.

[6] She is originally part of the team investigating the murder of Miguel Prado's (Jimmy Smits) brother Oscar (Nick Hermz), but because of her lack of tact and people skills she is removed from the case by the newly promoted Angel Batista (David Zayas).

Her relationship with Anton begins to suffer at this point, especially when Lundy returns to Miami to hunt the Trinity Killer (John Lithgow).

[12] Debra then renews her search for Harry's mistress, and finds out about Laura Moser, and the fact that Dexter and the Ice Truck Killer are brothers.

[13] Debra begins an intimate relationship with Quinn while trying to support Dexter following Rita's murder (portrayed in the season four finale, "The Getaway").

She figures out that Jordan Chase (Jonny Lee Miller), a prominent public speaker, is involved with the group of men killing the girls, but cannot prove her suspicion because he never appears on the DVDs.

She finally makes peace with the idea — on the same day that she catches Dexter in the act of murdering "Doomsday Killer" Travis Marshall (Colin Hanks).

[18] Dexter slips away from Debra long enough to dispose of Ray Speltzer (Matt Gerald), a serial killer she had tried and failed to send to prison.

[20] Their truce is threatened when Dexter begins dating Hannah McKay (Yvonne Strahovski), a serial poisoner whom Debra is intent on arresting for the murder of Sal Price (Santiago Cabrera), a writer she had feelings for.

Later, at Batista's New Year's Eve party, she learns that LaGuerta has gone in pursuit of Dexter, who she fears is in the act of killing Hector Estrada (Nestor Serrano), the man who ordered his mother's murder.

[24] Six months after LaGuerta's death, Debra's life has gone into a tailspin: She has quit her job, started drinking heavily, and cut off all contact with Dexter.

Dexter shows up at her hotel and tells her that an assassin named El Sapo (Nick Gomez) is coming to kill her and Briggs; Debra responds that she doesn't care.

Just as Debra is about to tell Quinn the truth about LaGuerta's death, Dexter renders her unconscious with the same tranquilizer he uses on his victims, and takes her back to his apartment.

When Dexter appears reluctant, Debra goes to her boss Jacob Elway (Sean Patrick Flanery) and offers to apprehend Hannah for a substantial reward.

[32] In her first case, Debra helps Dexter catch Oliver Saxon (Darri Ingólfsson), a serial killer known as "the Brain Surgeon".

[36] Eventually, however, Dexter decides to teach Harrison the "Code of Harry", and the two of them kill Caldwell's father Kurt (Clancy Brown), a serial killer who has been preying on teenage girls for 25 years.

[38] Brendan Bettinger noted that since the start of the series, "when she was just a pawn in the game of Dexter's serial killer brother, Deb has functioned as a bit of a Job for the writers."

In Season two, she starts going out with a man named Gabriel whom she met at the gym, and whom she suspects (incorrectly) of trying to use her notoriety following the Ice Truck Killer case to jumpstart his writing career.

After Dexter is freed thanks to his brother Brian's machinations, she refuses to let him see the children and communicates with him only to get him to sign the paperwork to finalize the adoption.

[42][43] Australian journalist Jack Marx describing her portrayal of "cool and clumsy" Debra as "so perfect that many viewers appear to have mistaken the character's flaws for the actor's."

Chris Holt of Starburst called Debra "kind of interesting and likeable, but her turbulent love life combined with the previously mentioned marriage of convenience sometimes makes the whole thing seem like CSI Miami written as soap opera.

The Guardian called the decision to bring her back "undoubtedly a smart move",[45] and LaToya Ferguson opined that Carpenter "arguably gives the most compelling performance of the series, somehow even livelier as Deb in death, while still being recognizable.

"[46] Conversely, Jen Chaney saw her appearances as grating at times,[47] and Alan Sepinwall, while praising Debra as the original series' most interesting supporting character, lamented that she "is still dead, and while she’s a more entertaining ghost than Harry was, there’s only so much to do with her.