premise: Ernest Medina participated in the My Lai Massacre.
hypothesis: Ernest Medina . 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 .