My Lai: the whitewash

Thirty years on, two survivors of the My Lai massacre stand next to a ditch where 170 died

In late 1969 the grisly details of My Lai were unleashed on the public, following a report by the investigative journalist Seymour Hersh.

Around the same time the army commissioned an investigation into the cover-up, which became known as the Peers inquiry.

More than 400 witnesses were questioned and 20,000 pages of testimony taken before the inquiry reported its findings in March 1970. Meanwhile an investigation by the army's Criminal Investigation Division (CID) was also conducted into the crimes committed at My Lai.

Lt Calley was the only soldier found guilty

The Peers report told a comprehensive story of what had happened on March 16, 1968. The crimes had included murders by individuals and groups, rape, sodomy, maiming and assault of civilians.

The report concluded that both Col Henderson, the brigade commander, and Lt Col Frank Barker, the commanding officer of the task force, had substantial knowledge of the war crime, but did nothing about it.

The Peers inquiry recommended that charges should be brought against 28 officers and two non-commissioned officers involved in the concealment of the massacre.

Charges dismissed and accused found not guilty

But the prospect of prosecutions crumbled . Army lawyers decided only 14 officers should be charged. Only one came to court, and he was acquitted.

A similar pattern emerged in the prosecution of the ground troops who had done the killing at My Lai.

The CID report said there was evidence to charge 30 soldiers with major crimes. 17 had left the army and charges against them were quietly dropped. Elsewhere charges were dismissed or the accused found 'not guilty'.

Fort Benning, where Calley spent three years under house arrest

The judicial process was labelled a whitewash by those who had fought to bring the soldiers of Charlie Company to book.

In the end, Charlie company's commanding officer, Lt Calley, was the only one to be convicted. He was sentenced to life imprisonment with hard labour. Within three days he was out of prison, pending appeal, on the personal instructions of President Richard Nixon.

He spent the next three years under house arrest at Fort Benning in Georgia. Freed on bail in 1974 his sentence was then cut to 10 years. Later that year he was paroled after completing one third of his sentence.

Meanwhile, the survivors of My Lai were mourning the deaths of more than 500 innocent civilians.

• Part 1 - Murder in the name of war: My Lai
• Part 2 - My Lai: the cover-up
• Part 3 - My Lai: the whitewash
• Part 4 - Timeline: Vietnam war 1945-1975
• Part 5 - Heroes of My Lai honoured