A cell at New York's Rikers Island jail. About 1,000 people die in American jails every year, and about a third of those are suicides. Seth Wenig/AP hide caption

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Inmates at California's Chino State Prison exercise in the prison yard in 2010. A proposition that was passed in the state last year reclassified certain crimes, releasing thousands of inmates earlier than had been anticipated. Kevork Djansezian/Getty Images hide caption

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Metropolitan Division officers finish another "rollback" operation. They searched the apartment of a paroled armed robber and gang member. These rollbacks are a cornerstone of the Metro Division's strategy of tracking people who may re-offend, and suppressing crime before it happens. Martin Kaste/NPR hide caption

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Taser International is now selling police departments the technology to store videos from body cameras. Patrick T. Fallon/Bloomberg via Getty Images hide caption

itoggle caption Patrick T. Fallon/Bloomberg via Getty Images

License plate scanners have helped police locate stolen vehicles and have even assisted in murder investigations. But with their ability to track a person's every move, skeptics worry about privacy. Pablo Martinez Monsivais/AP 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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