First Sergeant L.S. Harris is a member of the 33rd Infantry that appears in Spec Ops: The Line.
Little is known about what L.S. Harris's responsibilities were, though given his title and the presence of a photo of him in the Grey Fox's plan for the assault on The Gate, it can be assumed that he was in charge of operations there. It is unknown if he is killed in Captain Walker's, and Delta Squad's, assault, or if he survived.