Donald "Ducky" Mallard (2 October 1933–May 2023) was a Scottish-American coroner who worked for the NCIS as Chief Medical Examiner from 1992 to 2019, and NCIS Historian from 2019 to his death. Prior to working for NCIS, Mallard served in the British Army's Royal Army Medical Corps at the rank of Captain, serving in theaters such as Afghanistan, Bosnia, and even Vietnam due to an officer exchange program during the Vietnam War. Mallard died in his sleep in May 2023, having served the NCIS for over 30 years.