David McCallum, the actor who played Ducky on NCIS, was not originally the preferred choice for the role. However, his performance as the beloved team member for 20 years proved doubters wrong. McCallum's recent death at the age of 90 devastated fans of the show. He initially intended to retire after season 15 but changed his mind, continuing on as the part-time historian. The studio had reservations about casting McCallum as Ducky, but the show's creator, Don Bellisario, was adamant.
In the end, McCallum's portrayal of Ducky became gold.
