Dexter: Original Sinwill tell the story of Dexter’s early years and his first kills, and we already know of six of his victims that could appear in the upcoming show.Dexter: Original Sinwas recently announced alongside another series,Dexter: Resurrection. WhileResurrectionwill continue Dexter’s story after theending ofDexter: New Blood,Original Sinwill explore the distant past of the serial killer’s life. While the story of Dexter’s early adulthood has mostly been left untold, other shows in the franchise have already revealed six of his earliest victims.

Thetimeline ofDexter: Original Sinplaces the prequel show in the early 1990s, and there are a few victims thatDexter,New Blood, and a forgotten web-series began to reveal from that time frame. While the exact dates of Dexter’s kills aren’t well-established, and there have been some minor retcons to his first kills, there are still six victims who could easily appear inOriginal Sin. There’s no telling whether the upcoming show will actually include these characters or simply change them, but they’re still worth learning about.

Patrick Gibson as Dexter Morgan Next to Trinity and Rita

Dexter: Original Sin: 3 Characters the Prequel Must Avoid

While Dexter: Original Sin will feature the younger versions of popular characters from the original series, there are some characters the prequel should avoid.

6Nurse Mary

Dexter Season 1, Episode 3 - “Popping Cherry”

The first, and most important, of Dexter’s kills thatDexter: Original Sinwill likely depict is also his first ever kill. Nurse Mary was the first person Dexter ever killed, and the original series actually went into a good amount of detail about her.Mary was Harry Morgan’s nurse when he was first hospitalized for heart disease, and Dexter’s father quickly realized that she was poisoning him. Harry then learned that she had been giving him and other patients overdoses of morphine, and that she was a serial killer. To save his own life and her future patients, Harry told Dexter to stop her.

All 12 Times Dexter’s Kills Broke The Code Of Harry

Although Dexter Morgan claimed to kill strictly based on the Code of Harry, there were several occasions when he broke those sacred rules.

Since Mary was Dexter’s first victim, his killing ritual was much sloppier and less refined. Like usual, Dexter covered Mary’s apartment in plastic lining and ambushed her when she came home, but she was able to briefly stop him from injecting her with the tranquilizer. Dexter did eventually get her onto the table, and she told him that she wanted to take her victims' pain away.Dexter then killed Mary, and Harry lived for another year since he was no longer being given overdoses of morphine.

Harry-Morgan-and-Dexter-Morgan-in-Dexter

Dexter: Resurrection

Expected Summer 2025

Of all six kills that fitDexter: Original Sin’s timeline, Nurse Mary is the most likely to be depicted on-screen, simply due to its importance. It wouldn’t make much sense for a show depicting Dexter’s origins to not include the first person he ever killed, and since Mary had such a prominent role inDexterseason 1, it wouldn’t make much sense to change her story. Of course,Original Sincould also skip over Mary and pick up with Dexter’s life after he killed her, but if it does show her death again, it could give some valuable new insights into Dexter’s first victim.

5Unnamed Second Victim

Dexter Season 8, Episode 2 - “Every Silver Lining…”

Unfortunately, almost nothing is known about Dexter’s second victim.The only reason his second victim is known at all is thatDexterrevealed both Nurse Mary, Dexter’s first victim, and an unnamed drug dealer who was his third victim. While that leaves very little information about who Dexter’s second victim was, there are some context clues that can help determine what happened in his second outing as a serial killer.

Dexteralready showed that he was fairly unrefined in his first kill, Nurse Mary, and it’s safe to assume that his second kill was similarly disorganized. He likely learned a few lessons from his first outing, like how to ambush people from behind, but he was more than likely still working out some kinks in his modus operandi.Additionally, since Harry mentioned that Dexter started displaying photos of his targets' victims during his third kill, that means he didn’t have any photos on display for his second kill.

Dexter New blood dexters dark passenger always a family member harry deb

The possibilities are endless, which makes Dexter’s second victim a prime candidate to be put into the spotlight in Original Sin.

Since there are so few defined details about Dexter’s second kill, it seems extremely likely thatOriginal Sinwill examine it more closely than anything else in the franchise has.Dexter’s second victim is essentially a blank canvas, andOriginal Sincan depict it in any way without contradicting established canon. The possibilities are endless, which makes Dexter’s second victim a prime candidate to be put into the spotlight inOriginal Sin.

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4Unnamed Drug Dealer

There’s a bit more information about Dexter’s third victim than there is regarding his second kill, but not much. Thanks to the recordings of Harry’s conversations with Evelyn Vogel inDexterseason 8, there are a few key details about Dexter’s third kill. He was a drug dealer who robbed and killed two college students who had bought drugs from him.Harry also mentioned that Dexter’s third kill was when he started displaying photos of victims in his kill room. Vogel hypothesized that Dexter was displaying a basic understanding of justice at that moment, and it helped convince Harry to keep training Dexter.

Why Dexter’s Dark Passenger Is Always A Dead Family Member

New Blood brings Deb Morgan’s integral character back into the fold, but why is Dexter’s Dark Passenger always a dead family member of his?

Similarly to Dexter’s second victim, the unnamed drug dealer seems like a prime candidate to be shown onOriginal Sin.The previous shows haven’t revealed much about the drug dealer, which opens quite a few possibilities forOriginal Sinto explore his death and make it unique. Additionally, the drug dealer presents an opportunity for the prequel series to dive into Dexter’s practice of showcasing his targets' victims, which could be a very interesting way to explore his development as a serial killer and his internal sense of justice.

Michael C. Hall as Dexter Morgan softly smirking in front of crime scene tape

3Juan Ryness

Dexter Season 2, Episode 10 - “There’s Something About Harry”

Other than Nurse Mary, only one of Dexter’s earliest victims was actually shown on-screen inDexter.That was Juan Ryness, a pimp and drug dealer who was one of the last victims Dexter killed before Harry’s suicide.Dexterwas actually somewhat inconsistent with Juan, as he was originally described as just a pimp who was being let go because of a faulty warrant. InDexterseason 8, however, Harry told Evelyn Vogel that he walked in on Dexter killing a drug dealer who had also killed his partner on the police force.

Aside from the retcon, Juan Ryness actually plays a very important role in Harry and Dexter’s relationship. Juan was the first person Harry actually saw Dexter kill, and he couldn’t handle the sight of what his adoptive son had become.Harry puked when he saw the body, and as Captain Matthews explained, Harry killed himself by overdosing on his heart medication because he couldn’t handle the guilt. Harry obviously died as a result of Juan’s murder, but his reaction also haunted Dexter for a long time, and it was a big reason he let Miguel Prado learn so much about his Dark Passenger.

Dexter Morgan (Michael C. Hall) in front of a collage of blood slides on a pink background

Dexter

Cast

Dexter is a television series following Dexter Morgan, a blood spatter analyst for Miami Metro Police who secretly leads a dual life as a vigilante serial killer. Released in 2006, the show focuses on Dexter’s internal conflict as he hunts down criminals who elude justice within the legal system.

Since Juan Ryness' death had such far-reaching repercussions, there’s a good chance he’ll appear inDexter: Original Sin.The prequel show seems to be focused more on Harry than the original series ever was, and such a critical moment in his relationship with Dexter likely means that Juan Ryness is the perfect victim to include. However, given how important Juan is to Harry’s suicide, he likely won’t be tackled until nearly the end ofOriginal Sin, or at least closer to when Harry dies.

2Robert Milson

Dexter: Early Cuts - “Dark Echo”

The two remaining victims who Dexter likely killed in the 1990s were both from the Showtime web-seriesDexter: Early Cuts. That web-series depicted a handful of Dexter’s kills prior to 2006, whenDexterbegan and when he first encountered the Ice Truck Killer, and only two of them happened in the 1990s.One of his victims at the time was Robert Milson, a criminology professor at Dexter’s college.Early Cutsexplained that Harry had been tracking Robert ever since he was 15, as Robert had been acquitted of a murder charge for strangling his girlfriend at the time.

Dexter: Original Sin’s Story Was Already Shown On-Screen In A Forgotten Prequel From 16 Years Ago

Dexter: Original Sin will show Dexter’s earliest kills, but another show already depicted some of them years before the prequel series releases.

Dexter began hunting Robert shortly after Harry’s death, and he moved fairly quickly.He learned that Robert had killed seven young women who took his class over the years and dumped their bodies in the Everglades. Dexter ambushed Robert while he was grading papers and killed him in his office. He then dumped Robert’s body in the Everglades, both because he didn’t have access to his boat at the time and because Harry had taught him that bodies decay extremely quickly there.

As a free web-series,Early Cutsdoesn’t seem like an essential part ofDextercanon, and the upcoming prequel series could easily disregard it.

There’s only a small chance thatDexter: Original Sinwill include Robert Milson. The trailer forOriginal Sinshowed Dexter in a cap and gown, and since the show will depict his first days working with Miami Metro as a blood spatter analyst, it seems like he’s out of college.That would mean the show is set after Robert’s death, but it could always be shown in a flashback, andOriginal Sincould simply change the chronology ofEarly Cuts. As a free web-series,Early Cutsdoesn’t seem like an essential part ofDextercanon, and the upcoming prequel series could easily disregard it.

1Peter Thornton

Dexter met one of his earliest rivals through Robert Milson inEarly Cuts, and he could make the jump intoOriginal Sin.Peter Thornton was Robert’s teaching assistant, and when he stumbled into Robert’s audience to help him with grading, he witnessed Dexter killing the professor. Peter then engaged Dexter in a game of cat and mouse by capturing another of his targets before Dexter could get to her. After Peter killed her, Dexter met up with him and refused to teach him the Code of Harry, even though he called Peter his “dark echo.”

Dexter: Early Cutsis available to watch on YouTube.

After Dexter rejected him, Peter continued his killing spree by murdering a campus guard so that Dexter would find him. Since he had taken an innocent life, Dexter decided to kill his echo.He left a message for Peter, telling him to meet him in a warehouse, and after a brief struggle, Dexter had him on his table. Just before taking a circular saw to his neck, Dexter told Peter how he was honoring his father by killing other killers. Interestingly, Peter is technically one of the fewcharacters who knew about Dexter’s dark passenger.

Why Dexter Morgan Really Takes Blood Slides As Trophies (Is It A Plot Hole?)

Dexter Morgan took slides of his victims' blood as trophies, but they often got him into trouble, and they went against the Code of Harry.

Interestingly, the biggest reason Peter Thornton may not be included inOriginal Sinisn’t because he comes fromEarly Cuts, but because he would be redundant. The originalDextershow already explored the idea of Dexter having a protégé - twice, in fact. Dexter tried to teach both Miguel Prado and Lumen Pierce how to kill according to Harry’s Code, and Peter’s story would feel very similar to theirs.Dexter: Original Sinwill probably try to find its own footing without rehashing the same storylines as the originalDexter, and Peter will likely be left on the cutting room floor.