In search of the 48th Viet Cong (VC) Local Force Battalion, the unit entered Son My village but found only women, children, and old men. Frustrated by unanswered losses due to snipers and mines, the soldiers took out their anger on the villagers, indiscriminately shooting people as they ran from their huts and systematically rounding up the survivors, allegedly leading them to a nearby ditch where they were executed.
Reportedly, the killing was only stopped when Warrant Officer Hugh Thompson, an aero-scout helicopter pilot landed his helicopter between the Americans and the fleeing South Vietnamese, confronting the soldiers and blocking them from further action against the villagers. The incident was subsequently covered up, but eventually came to light a year later.
An Army board of inquiry, headed by Lt. Gen. William Peers, investigated the massacre and produced a list of 30 persons who knew of the atrocity, but only 14, including Calley and his company commander, Captain Ernest Medina, were charged with crimes. All eventually had their charges dismissed or were acquitted by courts-martial except Calley, whose platoon allegedly killed 200 innocents. He was found guilty of personally murdering 22 civilians and sentenced to life imprisonment. Still, his sentence was reduced to 20 years by the Court of Military Appeals and further reduced later to 10 years by the Secretary of the Army. Proclaimed by much of the public as a “scapegoat,” Calley was pardoned by President Richard Nixon in 1974 after serving about a third of his 10-year sentence.