The complex relationship between Leroy Jethro Gibbs and his father is a key aspect of his character in "NCIS." Ralph Waite portrayed Gibbs' father, Jackson, in eight episodes of the show. The storyline focusing on Jackson's death arose from Waite's own passing in 2014. Prior to "NCIS," Waite was best known for his role as John Walton Sr. in "The Waltons," appearing in 196 episodes. He also had a successful career in film and television, including roles in "Cool Hand Luke," "Cliffhanger," and "Carnivàle." Waite's final screen credit was in the soap opera "Days of Our Lives."