Debuting in the Season 1 episode “Split Decision,” Jimmy is introduced as a temporary replacement for Ducky’s assistant Gerald Jackson (Pancho Demmings), though eventually he takes on the role full-time after Gerald departs from the team. Jimmy assists Ducky with autopsies at NCIS headquarters and provides comic relief in the form of recurring bits. As the years went on, Palmer became a recurring, friendly, and funny face to contrast the serious crimes and despicable criminals the team squared off against.
As a result of his popularity and comedic niche, Jimmy became part of the team proper, especially in episodes like Season 14’s “Keep Going,” in which Jimmy puts himself at risk going out on a ledge to talk a suicidal man out of leaping to his death. The episode sees Jimmy open up about his own doubts, fears, and insecurities and the deep and abiding respect he has for his teammates and for Gibbs in particular.
If you or anyone you know is having suicidal thoughts, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).