In the early 1980s Mercedes Doretti, a student of anthropology in Buenos Aires, began helping in the search for some of the victims of Argentina's military rule. She went on to form the prestigious Argentine Forensic Anthropology Team, which has carried out exhumations in more than 30 countries. Her work gathering evidence of some of the worst atrocities of our times, has taken her to Bosnia, South Africa, El Salvador and Mexico. Mercedes spoke to Mike Lanchin about the challenges of her harrowing task and about a life-time dedicated to the cause of truth and justice. Photo: Mercedes Doretti excavates a skull from what used to be the convent of the church at El Mozote, El Salvador, Oct. 1992. (AP Photo/Luis Romero)