Former US army captain Ernest Medina, a key figure in the My Lai massacre during the Vietnam war, has died in Wisconsin at the age of 81.
US troops under Capt Medina's command killed hundreds of civilians in the small village in 1968. He was acquitted in a court martial over the massacre.
He died on May 8, according to an obituary written by his family. No cause of death was given.
Capt Medina was captain of Charlie Company, whose troops entered My Lai and a neighbouring community and massacred 504 unarmed Vietnamese villagers over three to four hours - mostly women, children and elderly men.