Eddie Adams, South Vietnam Police Chief Executing a Viet Cong (1968)
The narrative of this image involves not only what the viewer thinks about this particular incident: the larger story has to do with the violence of the war in Vietnam and America's military involvement.
One writer's comment about the victim:
“Plot twist: the 'innocent' guy who got shot was actually a Viet Cong murderer who killed some South Vietnamese police officers and some of their families.” -- Andrew Austin
Click here and here for discussions of the incident: the backstory and the political fallout.