Video: 'SYND 30 3 71 VERDICT DELIVERED AT THE TRIAL OF LEIUTENANT WILLIAM CALLEY'

(Monday, March 29, 1971, 4:31 p.m. EST; during the Vietnam War, part of the Indochina Wars and the Cold War) — U.S. Army First Lieutenant William Calley was found guilty today of the premeditated murder of at least 22 South Vietnamese civilians on Mar. 16, 1968, in the My Lai massacre.

Calley would be sentenced Mar. 31, 1971, to life imprisonment and hard labor at Fort Leavenworth, which includes the United States Disciplinary Barracks, the Department of Defense’s only maximum security prison.

The U.S. Army would reduce Calley’s sentence to 20 years on Aug. 20, 1971, and served only three-and-a-half years under house arrest.

Video: 'The Vietnam War - My Lai Massacre' (Mar. 29, 1971, at 1:12:23)

Calley was the only one convicted of the 26 officers and soldiers initially charged for their part in the My Lai massacre or the subsequent cover-up.

Many observers saw My Lai as a direct result of the military’s attrition strategy with its emphasis on body counts and kill ratios.