GUADALAJARA,MEXICO – OCTOBER 08: A woman lights a candle to protest the disappearance of 43 students from the Isidro Burgos rural teachers college in Ayotzinapa, Guerrero and demand authorities find them in. Federal agents have been sent to the area after the discovery of a mass grave and charges that local police may have conspired with a criminal gang to kill and disappear the students. (Photo by Servando Gomez Camarillo/LatinContent/Getty Images)