A protestor carries a cross that reads in Spanish: "Enough impunity", during a protest demanding the release of students detained during a massive protest on Nov. 20, 2014, in Mexico City, Tuesday, Nov. 25, 2014. Tens of thousands marched to the capital's main plaza last week, demanding that authorities find 43 missing college students. The march ended in violence when the demonstrators clashed with police and scores where detained and arrested. (AP Photo/Rebecca Blackwell)