Two days ago, the Economist posted this report on the My Lai Inquiry (H/T to Pete) on their YouTube channel. See also Calley's My Lai Apology.
The US Army conducted its own, secret inquiry into the massacre of civilians in Son My, South Vietnam on March 16th 1968, The My Lai Massacre. Tape-recordings were made of the more than 400 witnesses. Now, for the first time, these recordings can be heard along with the photographic evidence compiled by Lt General Peers and his inquiry team.