An officer from Brazilian Police Special Forces took aim Tuesday during the violent protest that broke out in one of Rio de Janeiro's slums. People there blame police for a young man's death, and say authorities are clamping down too hard in advance of this June's World Cup soccer tournament and the 2016 Summer Olympics, both of which will be held in Brazil. Christophe Simon /AFP/Getty Images hide caption

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Hundreds of thousands of people crowd Copacabana Beach in Rio de Janeiro on Sunday as Pope Francis celebrates the final Mass of his visit to Brazil. Security lapses, traffic chaos and other logistical snafus marred the visit. AFP/Getty Images hide caption

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A demonstrator is shot by a rubber bullet as anti-riot police officers charge during a protest Thursday against corruption and price hikes in Rio de Janeiro. Christophe Simon /AFP/Getty Images hide caption

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Mountains in the area where Marcelo first explored the wonders of the natural world. Leonardo Pallotta/Flickr hide caption

itoggle caption Leonardo Pallotta/Flickr