Sarah Michelle Gellar Joins 'Dexter' Prequel 'Original Sin'

Sarah Michelle Gellar has officially joined the highly anticipated spin-off series "Dexter: Original Sin" and will play a key role. Sarah Michelle Gellar has starred in the thriller "I Know What You Did Last Summer", "The Game", the American version of "The Grudge" and the TV series "Buffy the Vampire Slayer".

Sarah Michelle Gellar will play Tanya Martin in "Dexter: Original Sin", the head of the Crime Scene Investigation (CSI) of the Miami Metro Police Department and Dexter's new boss.

“Sarah Michelle Gellar is a pop culture icon who perfectly complements our stellar cast, including Christian Slater, Patrick Dempsey and more,” Nina L. Diaz, president of content and chief creative officer for Showtime/MTV Entertainment Studios and Paramount Media Networks, said in a statement. “We are thrilled to have her return to the Showtime/MTV Entertainment Studios family and to be a part of the origin story of the Dexter series.”

The prequel to Dexter, Dexter: Original Sin, is set in 1991 Miami, 15 years before the original Dexter. The new series tells the story of Dexter (Gibson) as he grows from a student to a vengeful serial killer. Under the guidance of his father (Slater), Dexter adopts a set of rules that help him find and kill people without being discovered by law enforcement, and he begins a forensic internship with the Miami Police Department.

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Cast of Dexter: Original Sin

Young Dexter

Dexter's adoptive father Morgan