Warning! This article contains SPOILERS for Dexter: Original Sin season 1, episode 4 and Dexter season 2.A dark theory aboutDexter: Original Sincould explain why Tanya Martin (Sarah Michelle Gellar) never appeared in the originalDexterseries. Thecast ofDexter: Original Sinfeatures quite a few returning names from the original show, like Vince Masuka (Alex Shimizu), Angel Batista (James Martinez) and Maria LaGuerta (Christina Millian). There are only a handful of entirely new characters at Miami Metro, one of whom is Tanya Martin. Since she was never mentioned in the original series, the prequel show will have to find a way to remove Tanya sometime betweenwhenDexter: Original Sintakes placeand when the original show began.
Now, it seems thatOriginal Sincould have a very inventive way of taking Tanya out. AfterDexter: Original Sinepisode 4, everyone is trying to findJimmy Powell’s killer. The detectives of Miami Metro have very few leads, and even their first theory - that Jimmy was killed by the cartel to punish his father, Judge Powell - is starting to look incorrect. One theory suggests that they’re looking in the wrong direction, and that they should be looking internally, specifically at Tanya Martin.

Tanya Martin Is Jimmy Powell’s Killer – Dark Dexter: Original Sin Theory Explained
Tanya May Have A Dark Passenger Like Dexter, & Her Inside Knowledge Of Law Enforcement Would Help Her Cover Her Tracks
Several people on Reddit - likeuser faejae0208- have theorized thatTanya Martin could be behind the kidnapping and subsequent murder of Jimmy Powell. The theory has some merit: it suggests that, like Dexter, Tanya was drawn to forensics because she also has a “dark passenger,” or at least an obsession with violence and death. At some point, Tanya would have started killing, and her knowledge of forensic work would have helped her remove any evidence that would tie her to any of her crimes. Tanya also knew exactly how much force cutting through a child’s finger would require, which would have helped her do the deed herself.
Dexter: Original Sin Season 2 - Confirmation & Everything We Know
Showtime’s Original Sin explores the life of Dexter Morgan in the early 1990s, and now the prequel series has scored a season 2 renewal.
The theory that Tanya is a serial killer would also fit with whatOriginal Sinhas revealed about the investigation into Jimmy’s death.The entire case has been quite confusing: Harry (Christian Slater) and other detectives first thought the cartel could be involved in Jimmy’s death. The way his body was displayed, however, and the fact that the kidnappers never demanded a ransom, thoroughly confused them. It might be that Tanya specifically targeted Jimmy because of her knowledge of law enforcement. She knew Miami Metro would assume it was the cartel’s doing, thus making it even harder for her to be caught.

Tanya Martin Could Be Dexter’s Final Kill In Original Sin Season 1
Dexter Typically Saves Each Season’s Main Antagonists' Death For The Finale
If Tanya does turn out to be Jimmy Powell’s killer, she might end up being the final person Dexter kills at the end ofOriginal Sinseason 1. For each of theeight seasons ofDexter, Dexter would be hunting a serial killer throughout the season. It would only be in the season finale, however, that Dexter would actually catch his prey and kill them: it happened witheveryDexterserial killer, from the Ice Truck Killer to the Brain Surgeon.Original Sinmay be waiting to give Dexter a chance to kill Tanya until the season finale.
Tanya Being Jimmy Powell’s Killer Would Open Up A Big Plot Hole For The Original Dexter Series
Tanya Martin being Jimmy Powell’s killer wouldn’t be a perfect choice, however, as it would open up a massive plot hole for the originalDexter.If there had been another serial murderer hiding in plain sight at Miami Metro, Dexter almost certainly would have mentioned it when he was lamenting how James Doakes (Erik King) was the only person who could tell he was odd. At the very least, he would have mentioned Tanya when Doakes was believed to be the Bay Harbor Butcher, and when he became responsible for the deaths of two different coworkers.
Lila Tournay (Jaime Murray) killed James Doakes inDexterseason 2, though Dexter had previously kidnapped the detective.

There’s another reason that the fact that Tanya was never mentioned in the originalDexteris so strange. Tanya is Dexter’s mentor in forensic science, but if she proves to be a killer, she could also become his mentor in another way. Dexter usually has conversations with his victims and tries to learn from them, and he would likely do the same with Tanya.If Tanya gave Dexter some pearls of wisdom about how to balance being a killer with hiding in plain sight, it would be even stranger that Dexter never thought to reminisce about her advice.
At this point in Dexter: Original Sin, it’s simply too early to tell for sure whether Tanya Martin is a killer.
There is also the chance that Tanya didn’t kill Jimmy Powell, and thatOriginal Sinwill have to find a different way to write her out of the show. Some theories have even suggested that Tanya will find out who killed Jimmy, and that she’ll be killed to protect the real murderer. At this point inDexter: Original Sin, it’s simply too early to tell for sure whether Tanya Martin is a killer. One thing is for certain, however: the show will have to deal with her in some fashion.
Dexter: Original Sin
Cast
Dexter: Original Sin explores Dexter Morgan’s early years in 1991 Miami as he transitions from student to avenging serial killer. Guided by his father, Harry, Dexter crafts a moral code and navigates a forensics internship at Miami Metro Police, all while controlling his darker impulses.
Dexter
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.