Sarah Michelle Gellar joins Dexter prequel "Dexter: Original Sin"

Sarah Michelle Gellar will play the role of Tanya Martin, the CSI chief and Dexter’s new boss.

The cast of Paramount+’s Dexter prequel, Dexter: Original Sin, continues to grow more impressive.

Emmy winner Sarah Michelle Gellar has joined the series, which explores the journey of a young Dexter Morgan, played by Patrick Gibson, as he transforms into an avenging serial killer in Miami.

Nina L. Diaz, president of content and CCO at Showtime, expressed excitement, stating, “Sarah Michelle Gellar is a pop culture icon who perfectly rounds out our best-in-class cast featuring Christian Slater and Patrick Dempsey among others. We’re thrilled to have her return to the Showtime/MTV Entertainment Studios family and join the origin story of the Dexter franchise.”

Gellar will appear as a special guest star in the role of Tanya Martin, the CSI chief at the Miami Metro Police Department and Dexter Morgan’s new boss.

The actress is widely recognized for her iconic role in the beloved WB series Buffy the Vampire Slayer, as well as her performances in films like Cruel Intentions, I Know What You Did Last Summer, The Grudge, and Scooby-Doo. She recently starred in and executive produced the Paramount+ series Wolf Pack.

The official description of the Dexter prequel reads: “Set in 1991 Miami, Dexter: Original Sin follows Dexter as he transitions from student to avenging serial killer. When his bloodthirsty urges can’t be ignored any longer, Dexter must learn to channel his inner darkness. With the guidance of his father, Harry (Slater), he adopts a Code designed to help him find and kill people who deserve to be eliminated from society without getting on law enforcement’s radar. This is a particular challenge for young Dexter as he begins a forensics internship at the Miami Metro Police Department.” 

Clyde Phillips has come back to the franchise as showrunner, having previously led some of the original series' most acclaimed seasons.

Patrick Dempsey will play Aaron Spencer, with Molly Brown cast as Dexter’s sister, Debra Morgan. Additionally, the series features James Martinez as Angel Batista, Christina Milian as Maria LaGuerta, Alex Shimizu as Vince Masuka, and Reno Wilson as Bobby Watt.