IGUALA, MEXICO - OCTOBER 13: A clandestine grave is seen at La Joya, in the outskirts of Iguala on October 13, 2014 in Iguala , Mexico. Mexican authorities found four more clandestine graves containing human remains near Iguala where 43 students went missing after a confrontation with local police that left 6 dead last september 26. (Photo by Miguel Tovar/LatinContent via Getty Images)