A demonstrator cries during a protest in support of missing Ayotzinapa Teacher Training College Raul Isidro Burgos students, outside the building of the office of Mexico's Attorney General in Mexico City October 15, 2014. On September 26, police allegedly linked to a criminal gang shot dead at least three students and abducted dozens of others during clashes in the southwestern city of Iguala. Forty-three of the students are still missing. [Photo/Agencies]