Academy Award-nominated and Emmy, Tony and Golden Globe award-winner John Lithgow will take on one of his most intense and intriguing roles to date portraying Miami's latest serial killer in Showtime's top-rated drama series Dexter. Lithgow will be featured in all 12 episodes of season four which are scheduled to premiere Sunday, September 27th on Showtime.

The premium cable network announced that Lithgow will play Walter Simmons, a mild-mannered suburbanite who moonlights as the Trinity Killer. One of America's most prolific serial killers, Trinity gets his name from his tendency to kill in threes and he's just relocated to Miami. Not only does the addition of a new killer in the community attract Dexter's (Michael C. Hall) interest and appreciation, but it also brings Keith Carradine's Agent Lundy back to town.

Lithgow, most recently seen guest-starring as himself on NBC's 30 Rock, is no stranger to killer roles, most notably in Brian DePalma's 1992 thriller Raising Cain."

In addition to Oscar nominations for Terms of Endearment and The World According to Garp," Lithgow has won four Emmys, including three for 3rd Rock from the Sun, two Tonys and a Golden Globe, among other laurels.