Actor David McCallum, best known for his role as Ducky on the crime drama NCIS, has passed away at the age of 90. McCallum played the quirky chief medical examiner for 15 seasons before leaving the show. He died peacefully surrounded by his family in New York. McCallum's son described him as a loving father with a passion for science and culture. CBS and the executive producers of NCIS paid tribute to McCallum, calling him a gifted actor and a beloved figure both on and off-screen.