David McCallum, the actor behind the iconic Dr. Donald "Ducky" Mallard on NCIS, has been a fan favorite since the show's beginning. Although he never fully departed from the CBS series ...

For decades, a fan favorite character on NCIS has been Dr. Donald "Ducky" Mallard. Played by David McCallum, the bow-tied coroner was a staple on the beloved television show ever since its inception.

Actor David McCallum, famed for his roles in "The Man from U.N.C.L.E." and CBS's "NCIS" joins Tanya Rivero to discuss his debut novel, "Once a Crooked Man." Intel Made a Mistake Decades Ago.