"Dexter" Main Cast and Characters

Keith Carradine as Special Agent Frank Lundy (Seasons 2 and 4)

Lundy is an FBI agent who takes over the Miami Police Department's investigation of Dexter's kills. He's a "rock star" of an agent with a reputation for capturing serial killers. His unorthodox style and authoritative demeanor attract Deb, and the two begin to date, although he's her superior. Dexter respects Lundy's skill and uses his own position inside the department to stay one step ahead of the agent.

Jimmy Smits as Miguel Prado (Season 3)

Prado is an assistant district attorney in Miami with whom Dexter forms a bond when they both go after the same criminal. Prado's fiery temper and enthusiasm for punishing evildoers -- even as he bends the law -- proves to be a double-edged sword for both him and Dexter.

Desmond Harrington as Joey Quinn (Seasons 3 - 6)

Quinn is a transfer to the Miami homicide division whose past history in narcotics is cloudy. As such, Deb becomes suspicious of his tactics and motives as they work closely together on cases. Dexter likewise has his doubts, as he witnesses Quinn's underhanded dealings -- in turn causing Quinn to cast a suspicious eye on Dexter and his frequent trips out of the office. Quinn's suspicions eventually cause inner turmoil as he debates whether to pursue Dexter in light of his developing affections for Deb.

John Lithgow as Arthur Mitchell (Season 4)

Outwardly, Arthur appears to be the perfect suburban husband and father of two, a high school teacher who volunteers building houses for the needy. Secretly, though, he's a serial killer, dubbed the Trinity Killer because of his repeated pattern of three kills in a short period of time. His home life is likewise not as cheery as it seems, as he uses physical and mental abuse to intimidate his family into keeping up the facade of perfection.

Julia Stiles as Lumen Pierce (Season 5)

Lumen fled her drab former life in Wisconsin (including her fiance) and came down to Miami to find herself, but what she found was trouble -- in the form of a group of sadistic men whose plot puts them squarely in Dexter's sights. But the headstrong and vengeful Lumen is not about to let him work alone.

Jonny Lee Miller as Jordan Chase (Season 5)

Jordan is a popular motivational speaker and master manipulater who holds a twisted secret that puts him at odds with Dexter and Lumen, two of the only people aware of his dark side.

Mos Def as Brother Sam (Season 6)

An ex-con who found religion in prison, Brother Sam is initially targeted by Dexter as a potential victim, but Dexter comes to realize that he has truly rehabilitated himself by cultivating a relationship with God.

Edward James Olmos as Professor Gellar (Season 6)

Gellar is a charismatic and influential religious studies professor moonlighting as a serial killer. Like Dexter, he believes his murders are just, basing his reasoning within a religious framework. Dexter becomes curious about Gellar's thought process when it comes to these acts and the thought process behind them, causing him to question his own beliefs.

Colin Hanks as Travis Marshall (Season 6)

Travis is a highly intelligent but impressionable young man who works as a museum antiques specialist. Under Gellar's manipulative control, he aids in the professor's string of religious killings.