premise: Ernest Medina was uninvolved in a Vietnam War mass killing.
hypothesis: Ernest Medina . He served during the Vietnam War and was acquitted in a court-martial of war crimes charges in 1971 . He was the commanding officer of Company C , 1st Battalion , 20th Infantry of the 11th Brigade , Americal Division , the unit responsible for the My Lai Massacre of 16 March 1968 . He was court martialed in 1971 for his role in the My Lai Massacre , but acquitted the same year . The Mỹ Lai Massacre ( thảm sát Mỹ Lai , [ tʰâːm ʂǎːt mǐˀ lāːj ] ; [ ˌmiːˈlaɪ ] , [ ˌmiːˈleɪ ] , or [ ˌmaɪˈlaɪ ] ) was the Vietnam War mass killing of between 347 and 504 unarmed civilians in South Vietnam on March 16 , 1968 . The Vietnam War ( Chiến tranh Việt Nam ) , also known as the Second Indochina War , and known in Vietnam as Resistance War Against America ( Kháng chiến chống Mỹ ) or simply the American War , was a war that occurred in Vietnam , Laos , and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975 .