A prequel about a young Arthur Mitchell could be greenlit soon — but who would play him?
It’s no secret that Showtime has no plans to walk away from the Dexter universe any time soon. Since its debut in 2006, Dexter has grown far beyond its original format—evolving into a full-fledged franchise. With a sequel (Dexter: Resurrection), a prequel (Dexter: Original Sin), and more spin-offs reportedly in development, it’s clear the network sees long-term potential in expanding the Dexter legacy.
One of the most intriguing projects reportedly in the works is a Trinity Killer prequel series, centered around a younger version of Arthur Mitchell—one of the most chilling and iconic villains in television history. The character, originally portrayed by Emmy winner John Lithgow, made his unforgettable mark in Season 4 of Dexter, and his presence continues to haunt fans to this day.
According to recent updates, the script for the Trinity prequel has already been completed. Showrunner Clyde Phillips confirmed this in an interview, sparking hope that production could begin soon. Even more exciting is the news that John Lithgow is set to return—not physically, but as a narrator or the inner voice of young Arthur Mitchell.
While the prequel hasn’t been officially greenlit yet, that’s largely because Showtime was waiting to gauge the success of Dexter: Original Sin. Now that Season 2 of the prequel is confirmed, the odds are high that the Trinity series will move forward in the near future.
Who Could Play Young Arthur Mitchell?
Of course, to bring this prequel to life, casting the right actor to portray a younger Arthur Mitchell is essential. While we don’t yet know what time period the series will cover or the exact age of the character, we can make some educated guesses. Here at Dexter Daily, we've curated a shortlist of five actors between the ages of 28 and 38 who we believe could do justice to such a complex role.
During a recent interview with Screen Rant, Lithgow offered this insightful advice to whoever takes on the role: “Just be on his side. Not an easy thing to do with the Trinity Killer, but be on his side.”
That one line perfectly captures the essence of Arthur Mitchell: a character both monstrous and, at times, disturbingly human.
Note: Since the series never revealed what a young Arthur Mitchell looked like, the casting choices below are more flexible regarding hair color and facial features. Elements like eye color, which can be easily altered, are less of a concern.
5 Actors Who Could Be the Perfect Young Trinity Killer
1. Freddie Highmore (Early 30s)
Known for: The Good Doctor, Bates Motel
Freddie Highmore has made a career out of playing psychologically complex characters. His performance as Norman Bates in Bates Motel was nothing short of haunting, making him a natural fit for a young Arthur Mitchell—particularly if the series explores Mitchell’s early descent into darkness.
2. Ben Schnetzer (Early 30s)
Known for: Pride, The Book Thief
Schnetzer has a quiet intensity and moral ambiguity in many of his roles. He could bring nuance and internal conflict to a character like Arthur Mitchell, who balances the facade of a family man with the horror of a serial killer.
3. Cory Michael Smith (Late 30s)
Known for: Gotham, Mountainhead
Smith is best known for portraying Edward Nygma (The Riddler) in Gotham, where he mastered the blend of intellect, obsession, and instability. His track record makes him a compelling contender for Trinity’s younger counterpart.
4. Lucas Hedges (Late 20s)
Known for: Manchester by the Sea, Boy Erased
With a gift for portraying emotionally layered characters, Hedges could effectively capture the internal torment that defines Arthur Mitchell—particularly if the prequel explores the trauma and origins of his violent tendencies.
5. Joe Keery (Early 30s)
Known for: Stranger Things, Fargo
Joe Keery has a boy-next-door charm with a subtle, simmering darkness—making him an unconventional but fascinating pick. His recent work has shown impressive range, which could translate well to the complexity of a character like Mitchell.
Final Thoughts
While none of these actors are mirror images of a young John Lithgow, casting isn't just about physical resemblance. As we've seen in Dexter: Original Sin, what truly matters is capturing the character’s essence—his mannerisms, inner conflict, and emotional layers. That’s what will resonate most with fans.
As we await official word from Showtime about the Trinity Killer prequel, speculation continues to grow. Fan reactions to the idea of a Trinity-centered series have been mixed, but with a compelling script, a strong lead, and the right creative team, this spin-off could become one of the most gripping additions to the Dexter universe yet.
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