From The Art and Popular Culture Encyclopedia
General Nguyen Ngoc Loan executing a Viet Cong prisoner in Saigon is a photograph take by American photographer Eddie Adams when he was covering the Vietnam War for the Associated Press in 1968; the picture of police chief General Nguyen Ngoc Loan executing a Vietcong prisoner, Nguyen Van Lem, on a Saigon street, on February 1, 1968.
Nguyễn Văn Lém was a member of the Viet Cong who was summarily executed in Saigon during the Tet Offensive. The execution was captured on film by photojournalist Eddie Adams, and the momentous image became a symbol of the hostility of war. The execution was explained at the time as being the consequence of Lém's suspected guerrilla activity and war crimes, and otherwise due to a general "wartime mentality."
The photograph was used on the cover of London Oz, issue 10, March 1968.