My Lai massacre

The My Lai massacre, as reported by a South Vietnamese army lieutenant to his superiors, was an "atrocious" incident of revenge. US forces deliberately murdered 400 civilians, shortly after a firefight with Viet Cong troops who had mingled with the villagers on March 16, 1968.

Background

According to University of Missouri-Kansas City law professor Doug Linder:

GIs joked that "anything that's dead and isn't white is a VC" for body count purposes. Angered by a local population that said nothing about the VC's whereabouts, soldiers took to calling natives "gooks." (source)

Courtmartial

American Lieutenant William Calley was convicted in 1971 of premeditated murder in ordering the shootings and initially sentenced to life in prison, but 2 days later, President Richard Nixon ordered him released from prison. Calley served 3 1/2 years of house arrest in his quarters at Fort Benning Georgia and was then ordered freed by a federal judge.