John Reese chooses an alias whenever situations require him to get in direct contact with a person of interest. Though his real last name is unknown (only the last letter, "s", is shown when Det. Carter reads his file in “Many Happy Returns”), his military records suggest his real first name is John. "John Reese" is an alias given to him by Kara Stanton. Finch, Carter, Fusco, Darren McGrady, Mark Snow, Alistair Wesley, and Sameen Shaw know him as John Reese.