Lithgow almost turned down Dexter

John Lithgow has revealed he nearly rejected the opportunity to play a serial killer in Dexter.

The 3rd Rock From The Sun actor already had an Italian holiday and cruise and his son's wedding planned - but while he made the ceremony, he postponed the trip after his wife Mary pushed him to take the part.

"She's the one who said, 'No, you've got to take the role,'" he recalled.

Lithgow guest stars as Arthur Mitchell, the so-called Trinity Killer whose victims come in threes and who both repels and attracts Michael C Hall's Dexter Morgan in the FX drama.

Lithgow said he enjoyed bringing the death-obsessed Mitchell to life.

"This man is very two-faced, like Dexter. A serial killer by definition is a man who presents himself in a very different way to the world," Lithgow said. "So it's an actor's field day figuring out what you reveal and what you don't."