Samuel W. Koster

Samuel W. Koster (December 29, 1919 – January 23, 2006) was the highest-ranking United States Army officer punished in connection with the My Lai Massacre. Koster was slated for promotion to the rank of Lieutenant General (three star) at the time he was charged, but was demoted and ended his military career in mild disgrace.

Born in West Liberty, Iowa, Koster graduated from West Point in 1942. He was a regimental executive officer in Europe during World War II, and directed the Eighth Army's guerrilla warfare operations during the Korean War. Koster attained the rank of Major General, and was placed in command of the Americal Division in Vietnam in 1967.

My Lai Massacre
On March 16, 1968, a company of Americal Division troops led by Captain Ernest Medina and Lieutenant William Calley slaughtered hundreds of civilians in a South Vietnamese hamlet known as My Lai (referred to as "Pinkville" by the troops). While no official count was made, soldiers and investigators later estimated that 350 to 500 women, children and old men were killed with grenades, rifles, bayonets, and machine guns; some were burned to death in their huts. Corpses were piled in ditches that became mass graves. No Viet Cong were ever discovered in the village and no shots were fired in opposition. To many Americans at home, the massacre marked the moral nadir of the war in Southeast Asia and became a pivotal event in the conflict.

Koster was not on the ground at My Lai, but he did fly over the village in a helicopter while the soldiers moved in, and afterward. He later testified that he believed only about 20 civilians had died, although he also said that he was told about "wild shooting" and about a confrontation between ground troops and a helicopter pilot (later identified as Hugh Thompson) who tried to stop the killing of civilians. Koster later ordered subordinates to file reports on the incident, but they were incomplete, and one was even lost. Worse, these reports were never sent to headquarters, as military protocol required, until an Americal veteran named Ron Ridenhour triggered a secret high-level investigation with a three-page letter he sent to the Pentagon, the president, and members of Congress in March 1969. Freelance investigative journalist Seymour Hersh broke the story of the massacre to the wider public in November 1969.

Early in 1970, Koster and 13 other officers were charged with trying to cover up the massacre. Charges were dropped, however, after the Army determined that he "did not show any intentional abrogation of responsibilities". Koster, who was the Superintendent of the United States Military Academy at West Point at the time, was due to be promoted to the rank of Lieutenant General (three-stars), but his involvement in the My Lai coverup caused him to be denied this promotion, and further inquiries led the way to his demotion. He was subsequently censured, stripped of a Distinguished Service Medal and demoted one rank, to Brigadier General, for failing to conduct an adequate investigation.

Later life
Following his demotion, Koster was reassigned to become deputy commander of Maryland's Aberdeen Proving Ground, in charge of Army weapons testing. He retired from the military in 1973. His decorations included the Silver Star, the Bronze Star Medal, and the Legion of Merit. His sons are career Army officers, two having graduated from West Point.

After his retirement, Koster worked for 12 years as an executive vice president for the power transmission division of Koppers and Hanson Industries in Baltimore, overseeing power plants in the United States and Canada.

Cultural references
Koster is mentioned by name in the first stanza of Pete Seeger's Vietnam protest song "Last Train to Nuremberg".

"Do I see Lieutenant Calley? Do I see Captain Medina?  Do I see Gen'ral Koster and all his crew?"