Mark Harmon (1951-present) is an American actor, producer, and author known for his long-running role on the hit television drama NCIS as investigator Leroy Gibbs. He starred in several feature length films in addition to a long resume of TV roles.

Leon Carroll was a commissioned officer in the US Marine Corps before joining the Naval Criminal Investigative Service (NCIS) and serving in seven locations over 20 years. After retirement, he worked as technical advisor on the TV show NCIS, where he met Mark Harmon. His experience with the NCIS is evident in the book, as it is in the show’s portrayal of Naval investigators in action.

In the Introduction for Ghosts of Honolulu: A Japanese Spy, A Japanese-American Spy Hunter, and the Untold Story of Pearl Harbor, authors Mark Harmon and Leon Carroll explore the responsibilities of working on the TV show NCIS, which is based on the real Naval Criminal Investigative Service. They hope to pay homage to the real investigators and uncover heroes who have gone unsung despite their contributions to the United States—heroes like Douglas Wada, one of the primary figures in the book. The text is the first in what the authors hope will be a collection of real-world histories of the NCIS investigators who changed history.