Who was Ronald Ridenhour and how did he investigate the My Lai Massacre?

Ronald Ridenhour was a helicopter door gunner who had previously trained with members of Charlie Company, the unit responsible for the My Lai Massacre. After hearing accounts of the atrocities from soldiers who had been present on March 16, 1968, Ridenhour began an informal investigation into the event, which was then referred to as the "Pinkville incident."1

During his remaining time in Vietnam, Ridenhour actively gathered eyewitness testimony from those involved. After returning to the United States and separating from the Army, he compiled his findings into a formal report. On March 29, 1969, he mailed this document to members of Congress, the Pentagon, and other officials in Washington. Ridenhour’s courageous actions were instrumental in breaking the silence surrounding the massacre, as his letter directly sparked the official investigations into both the killings and the subsequent military cover-up.1