The Akron Police Department training class works out at Kent State Basic Police Officer Training Academy. Donald Clayton is the only African-American in the class of 20. M.L. Schultze/WKSU hide caption

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A Philadelphia police officer demonstrates a body-worn camera being used as part of a pilot project last December. Matt Rourke/AP hide caption

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One demonstrator advocates for paid sick leave at a 2013 rally outside New York's city hall. The city is now one of several in the U.S. to have passed a measure mandating paid sick days. Spencer Platt/Getty Images hide caption

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A demonstrator rallies outside the U.S. Chamber of Commerce against the Supreme Court's decision in favor of Citizens United five years ago. Eight protesters at the Supreme Court were arrested and charged. Nicholas Kamm/AFP/Getty Images hide caption

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Demonstrators remember Michael Brown on Martin Luther King Jr. Day, marching from the apartment complex where Brown was killed to the Ferguson police station. A federal inquiry has found no evidence that officer Darren Wilson violated Brown's civil rights, sources tell NPR. Scott Olson/Getty Images hide caption

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Former air marshal Robert MacLean blew the whistle after he was informed that missions on overnight, long-distance flights were being canceled. The announcement came just days after air marshals were warned of terrorist threats. LM Otero/AP hide caption

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