 In 1917, Smith took up a post as medico-legal advisor to the Government of Egypt and senior lecturer in forensic medicine at the School of Medicine in Cairo.Smith went on to establish himself as an authority in the field of ballistics and firearms in forensic medicine, publishing the first edition of "Textbook of Forensic Medicine" in 1925.In 1928, Smith was appointed to the Regius Chair of forensic medicine at the University of Edinburgh.