For heroism while serving at Naval Station Norfolk Security Detachment, Norfolk, Virginia on 24 March 2014. While performing his duties as Chief of the Guard, Petty Officer Mayo was alerted to a suspicious individual walking towards USS MAHAN (DDG 72) on Pier 1, Naval Station Norfolk. Petty Officer Mayo pursued the individual up the brow of the ship while both he and the Quarterdeck watch-standers directed the individual to stop and provide identification. Failing to comply, the individual approached the Quarterdeck, attacked and disarmed the Petty Officer of the Watch. After boarding the ship, Petty Officer Mayo realized that the Petty Officer of the Watch no longer had control of her weapon. With complete and total disregard for his own personal safety, Petty Officer Mayo immediately placed himself between the Petty Officer of the Watch and the assailant. While fearlessly engaging the assailant and shielding the Petty Officer of the Watch, Petty Officer Mayo was fatally wounded. His exceptionally brave actions saved the lives of four watch-standers and ensured the safety of the entire crew of USS MAHAN (DDG 72). By his courageous and prompt actions in the face of great personal risk, Petty Officer Mayo prevented the loss of lives, thereby reflecting great credit upon himself and upholding the highest traditions of the United States Naval Service.