A noisy backhoe digs up earth to uncover yet another mass grave in Iraq, human remains are exhumed and the forensics experts get to work on their grim task. A skull is freed from a layer of clay, a tibia is placed in a body bag, all bound for a laboratory to be genetically cross-referenced with blood samples from relatives of the disappeared. The site in the central city of Najaf is one of many in a country that suffered through more than four decades of bloody conflict and turmoil. IMAGES AND SOUNDBITES