"They say that dead men tell no tales," but in fact they do. Many stories have been told by investigators unearthing mass graves in the Balkans, Central America, and elsewhere. Information gathered from mass graves can help resolve disputes about the nature of communal or international conflict, and shed light on historical facts. With modern forensic science, mass graves yield evidence that can be used to prosecute war crimes and other violations of international humanitarian law. Mass graves may even help to relieve the anguish of families whose loved ones disappeared in a time of war. In Cambodia mass graves dating to Cambodia's 1975 to 1979 revolution have told all these tales, and more.

The Communist Party of Kampuchea, popularly known as the Khmer Rouge, led Cambodia's revolution. It was one of the most violent revolutions of the twentieth century. Demographers estimate that two million or more lives were lost in the four...