In frame #15A of this sequence, South Vietnamese Gen. Nguyen Ngoc Loan, chief of the national police, fires his pistol into the head of suspected Viet Cong officer Nguyen Van Lem (also known as Bay Lop) on a Saigon street, Feb. 1, 1968, early in the Tet Offensive. The photo became one of the most recognized images of the Vietnam War, and won a Pulitzer Prize for Associated Press photographer Eddie Adams. (AP Photo/Eddie Adams)