According to Showtime, Lithgow will portray unassuming suburbanite Walter Simmons, who lives a dual life as a serial killer dubbed the Trinity Killer. Lithgow has been signed to appear in all 12 episodes of the series. The new season premieres Sept. 27. Michael C. Hall (Cabaret, Chicago) stars in the title role as a forensics expert who happens to be a serial killer with a penchant for murdering those who "deserve" it. As part of the upcoming season, Dexter becomes fascinated by the Trinity Killer's ability to evade capture for nearly 30 years.
The popular series also stars Tony nominee Keith Carradine (Will Rogers Follies, Dirty Rotten Scoundrels), Jennifer Carpenter (The Crucible, "The Exorcism of Emily Rose"), Lauren Velez (Intimate Apparel), David Zayas (Anna in the Tropics, Our Lady of 121st Street), James Remar (Bent, California Dog Fight, "Sex and the City"), Julie Benz and C.S. Lee.
Lithgow most recently appeared in the Broadway revival of Arthur Miller's All My Sons. His stage credits also include Dirty Rotten Scoundrels, The Retreat From Moscow, The Changing Room, Requiem for a Heavyweight, Sweet Smell of Success and M. Butterfly. His screen credits include "3rd Rock from the Sun," "30 Rock," "Dreamgirls," "Kinsey," "The Life and Death of Peter Sellers," "Redwood Curtain," "The Pelican Brief," "Terms of Endearment" and "Raising Cain."
The fourth season of "Dexter" will air Sundays at 9 PM on Showtime. For more on "Dexter," visit the Showtime official website at Showtime/Dexter