Pablo Cote holds a photo of his deceased father of the same name in July 2013 in Tlaxcala, Mexico. Cote was kidnapped while driving back from the U.S. border to the east-central state of Tlaxcala. He was beaten to death, part of the mass killing of 193 bus passengers and other travelers by the Zetas. Ivan Pierre Aguirre/AP hide caption

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A woman walks toward the international crossing gate in Nogales, Ariz., in March 2013. Jahi Chikwendiu/Washington Post via Getty Images hide caption

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French riot policemen force out migrants who were hidden in a truck that was making its way to the ferry terminal in Calais in western France on Wednesday. The cross-Channel port has become the last barrier for economic and political migrants trying to enter Britain illegally. Pascal Rossignol/Reuters/Landov hide caption

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An Armed Forces of Malta ship carrying rescued migrants arrives at an AFM base in Valletta last October. The number of migrants trying to make their way from the North African coast to European waters has ballooned in recent years. Darrin Zammit Lupi/Reuters/Landov hide caption

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A slide of migratory flows in the Mediterranean Sea from the Mare Nostrum operation is displayed in the control room of the Italian operation, which tracks and intercepts migrant ships en route to Europe. Sylvia Poggioli/NPR hide caption

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An African migrant infant is handed off by a member of the Red Cross to a member of the Spanish coast guard in the port of Tarifa on Tuesday. Marcos Moreno/AFP/Getty Images hide caption

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Illegal immigrants watch from behind a fence as police patrol the perimeter of a detention center at Amygdaleza, on the northern fringes of Athens, on April 30, 2012. Thanassis Stavrakis/AP hide caption

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Illegal immigrants captured in the Libyan coastal city of Surman are held at a temporary prison in an eastern district of Tripoli, Libya, on Oct. 19. Hamza Turkia/Xinhua /Landov hide caption

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A survivor of the shipwreck of migrants off the Italian island of Lampedusa looks out over the water Tuesday. The tragedy has bought fresh questions over the thousands of asylum-seekers who arrive in Europe by boat each year. Tullio M. Puglia/Getty Images hide caption

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