WARNING: SPOILERS ahead for Dexter: Original Sin season 1.

There have been many deaths in the first half of the Dexter prequel series Dexter implements Harry's code to satisfy his violent urges while making sure never to get caught. New episodes of Dexter: Original Sin release every Friday exclusively on Paramount+, except for a hiatus on January 17, 2024.

After Michael C. Hall reprised his iconic role as the charismatic vigilante serial killer in 2021's Dexter: New Blood, he returns as Dexter: Original Sin has already covered a few anticipated kills that were already established in Dexter's lore. Another Dexter series, Dexter: Resurrection, is expected to be released in the summer of 2025 with Hall also slated to return.

11 The Shapiro Family

Episode 1 "And in the Beginning..."

The first major deaths in the prequel series arrive in Dexter: Original Sin episode 1. Harry, Angel, and Captain Aaron Spencer investigate a murder scene at the Shapiro family home which left two parents and two children dead. The scene occurs at the beginning of the premiere episode as Harry's quick investigative work reveals a bloody fingerprint on the family's television remote. This provides Miami Metro PD with evidence linking Levi Reed to the crime scene, who tragically walks free after Harry screwed up the investigation by tossing out the corrupt alibi of Reed's girlfriend. Still, it's quite clear that Reed murdered the Shapiro family in episode 1.

10 Harry Morgan Jr.

Episode 1 "And in the Beginning..."

The most unexpected death in Dexter: Original Sin episode 1 is Harry Morgan Jr., who is revealed in a flashback to have drowned in the Morgan family swimming pool. Before Deb was born and Dexter was adopted, Harry had a biological son he called "Junior" with his former wife Doris Morgan. While Doris was out one day, Harry was in the living room watching a football game on television and drinking a beer.

While Harry was simply trying to unwind and catch a game, he failed to keep an eye on his young son who apparently didn't know how to swim. This tragic error led to Harry Morgan Jr.'s death by drowning and set up a previously unknown element of Harry Morgan's backstory before he and Doris adopted Dexter.

9 Victoria Sinclair

Episode 1 "And in the Beginning..."

Victoria Sinclair is not a major character in Dexter: Original Sin episode 1 but is the first person that leads a young Dexter to discover Nurse Mary and her "Dark enger". Sinclair was an elderly woman who Nurse Mary was supposed to take care of at a Miami hospital. Dexter read her obituary in Nurse Mary's scrapbook, which he discovered was a collection of Nurse Mary's trophies for all of her kills.

Dexter spots Nurse Mary smiling sinisterly as she "consoles" a member of Sinclair's family, which is how Dexter catches on to her. Once Harry's health starts to decline and shows no signs of improvement, Dexter figures out who Nurse Mary really is and discovers that she killed Victoria Sinclair along with several other patients.

8 Nurse Mary

Episode 1 "And in the Beginning..."

Dexter's first kill, Nurse Mary, occurs at the end of the Dexter: Original Sin premiere episode. As established in the Dexter original series, Nurse Mary was a serial killer disguised as a nurse who killed her victims by injecting them with an untraceable substance and calling it their medicine. This is how she was planning to kill Harry Morgan, who she believed deserved to die because of the poor life decisions he made about his health that brought him to the hospital in the first place. Nurse Mary's wrapped sense of playing God comes to an end when Dexter devises a way to kill her in her house, saving potentially dozens of future patients.

7 Raul Martinez

Episode 2 "Kid in a Candy Store"

At the beginning of Dexter: Original Sin episode 2, Dexter encounters his first crime scene as a member of Miami Metro PD. He investigates the body of Raul Martinez, who was shot in the head at close range in a parking lot outside a motel. Dexter quickly deduces that the killer shot Raul point-blank based on the blood spatter patterns on the ground. Since it's Dexter's first crime scene, he gets mildly hazed by Angel, Bobby, and Masuka but is inspired to discover who the murderer is so that he can try to set up his own kill number two.

6 Carla & Rene Carballo

Episode 2 "Kid in a Candy Store"

Dexter discovers more about Tony Ferrer by going out to a bar with Angel. Angel tells Dexter about the sad story of Carla and Rene Carballo, whose picture is hung up on the wall at the bar they're at. Angel reveals that Tony Ferrer set Rene up by giving him money with an extremely high interest rate, placing him in a staggering amount of debt. Rene wasn't able to pay Tony off when Tony came to Rene's house asking for his money back. As an intimidation tactic, Tony shoots at the wall next to Rene's head. The bullet went through the wall and killed Rene's mom, Carla, on the other side in the next room. Devastated by grief and guilt, Rene died by suicide.

5 "Handsome" Tony Ferrer

Episode 3 "Miami Vice"

Dexter's second kill, and the first one that required him to do some real scouting work, is Tony Ferrer. After learning about Carla and Rene Carballo, Dexter had all the justification he needed to take Tony off the streets. Tony may not have been a classic serial killer but he was a financial predator that fed off disadvantaged people within his own community.

Dexter killing Tony Ferrer likely saved a lot of people from making the same mistake as Rene and Raul did, which ended up costing them their lives. Dexter setting up Tony's kill in the center of a sports arena was a surprising yet innovative way for Dexter to take Tony out, demonstrating that young Dexter isn't afraid to get creative in Original Sin.

4 Jimmy Powell

Episode 4 "Fender Bender"

Dexter: Original Sin episode 4 opens up with the tragic death of a Miami judge's son, Jimmy Powell. Powell has been kidnapped and tortured by Original Sin's season-long villain, who is still unknown through five episodes of the prequel series. A masked man kept Powell locked in a dark room for several days before severing one of his fingers and sending it to the Miami Metro PD.

Since Jimmy is the son of a powerful judge, it seems like his kidnapping was intentional, although it still remains a mystery why he was killed if there was no desire for ransom money or something similar. Dexter and Miami Metro determined that Powell was killed before he was hung off of a Miami bridge and found by two joggers roughly 1.5 weeks after he went missing.

3 Blake Kersten

Episode 4 "Fender Bender"

Blake Kersten is a prostitute who was murdered by an unknown killer near a beach in Miami. Very little is known about Blake except Dexter is able to conclude that whoever killed him wanted to see the life squeezed out of his body, which implies that the murderer is a true serial killer who enjoys killing, like Dexter.

It's unclear at the halfway point in season 1 of the prequel series how Blake's death will affect the course of the story. It could be connected to another death that Dexter and Miami Metro discover. However, it's unlikely that it has anything to do with Jimmy Powell's death, indicating that there are likely two mass murderers at large halfway through Original Sin.

2 Anthony "Mad-Dog" Moretti

Episode 4 "Fender Bender"

Dexter's third target is ex-hitman Anthony "Mad-Dog" Moretti, played by Joe Pantoliano (The Sopranos, The Matrix). Mad-Dog proves to be Dexter's greatest challenger yet as a highly trained ex-hitman who spends most of his retirement on his boat. Dexter gets close to Mad-Dog by pretending to be interested in a fishing trip but learns more about Mad-Dog's past and why he killed, the answer obviously being money.

Mad-Dog doesn't end up being Dexter's third kill, however, because he woke up as Dexter was covering the kill room in plastic tarps. This sparked a fight between Mad-Dog and Dexter before Mad-Dog ran out into the street where he was hit by oncoming traffic. Due to these unexpected circumstances, Dexter couldn't add Mad-Dog's death to his personal trophy case and had to work quickly to remove all the evidence from Mad-Dog's house.