"It's a delicate subject matter, a really important subject matter. We wanted to make sure we did it properly and handled it properly," he tells TV Guide of the first and second installments of "Shell Shock."
"So there was a tremendous amount of research that went into this story, and I'm really proud of it."
In last week's NCIS, Gibbs and the team investigated after a Navy lieutenant's murder implicated Joe Westcott (guest star Brad Beyer), a Marine who was suffering from post-traumatic stress disorder.
After having lost many of his men during an ambush overseas, Westcott's fighting demons he doesn't fully understand. Since the show had already built a season-long theme of "fallen heroes,