David Letterman hosts his final Late Show episode on Wednesday. Jeffrey R. Staab/CBS hide caption

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Stacy Emminger holds the death certificate for her son, Anthony, who was addicted to heroin. His death was marked as a multidrug toxicity in Pennsylvania. Ben Allen/WITF hide caption

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Shannon Rivers, a member of the Akimel O'odham tribe, lights a fire for the purification ceremony at the Coconino County jail. Inmates will help him put blankets over the sweat lodge structure, place heated rocks inside and pour water over them. Laurel Morales/KJZZ hide caption

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The cast of Mad Men: January Jones (from left), Jon Hamm, Elisabeth Moss, Vincent Kartheiser, Christina Hendricks and John Slattery Frank Ockenfels 3/AMC hide caption

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Republican presidential hopeful Sen. Marco Rubio, R-Fla., speaks Wednesday before the Council on Foreign Relations in New York, where he laid out his "Rubio Doctrine." Mary Altaffer/AP hide caption

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David Letterman, seen here snapping a selfie with his replacement Stephen Colbert, will step down next week as host of the Late Show. Getty Images hide caption

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Officers stand watch at the intersection of West North Avenue and Pennsylvania Avenue as protesters walk for Freddie Gray in Baltimore in April. Gray died from spinal injuries about a week after he was arrested and transported in a police van. Jabin Botsford/The Washington Post/Getty Images hide caption

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Connie and Gerald Renfrow outside their Osage Avenue home. April Saul for NPR hide caption

itoggle caption April Saul for NPR

The neighborhood where the compound of the radical group MOVE was located. Peter Morgan/AP hide caption

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New York City Mayor Bill de Blasio is set to step onto the national stage with his progressive "Contract With America." Seth Wenig/AP hide caption

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Then-President George W. Bush jokes with his brother Jeb, the then-Florida governor, in 2006. Jeb Bush has been asked before, and is sure to be again, how he would distinguish himself from his brother. Mari Darr~Welch/AP hide caption

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