An inmate at Rikers Island juvenile detention facility carries a plastic fork behind his back as he walks with other inmates. A recent report found that juvenile detainees are subjected to routine violence, both by other inmates and by correction officers. Julie Jacobson/AP hide caption

itoggle caption Julie Jacobson/AP

In the past year, the U.S. prison population fell by roughly 4,800, the first time in decades the number has gone down, according to the Justice Department. Attorney General Eric Holder discussed the findings in New York on Tuesday. Julio Cortez/AP hide caption

itoggle caption Julio Cortez/AP

Dan Huff rests after a long day's work. He spent much of his life incarcerated in the California prison system. Now, he lives in drug- and alcohol-free transitional housing in Portland, Ore. Beth Nakamura for NPR hide caption

itoggle caption Beth Nakamura for NPR

Inmates from several Alabama state prisons take a math class at J.F. Ingram State Technical College. The campus becomes a medium-security facility when the students arrive. Dan Carsen/WBHM hide caption

itoggle caption Dan Carsen/WBHM

Hope House campers wear tie-dye shirts they made to the last day of camp at Western Correctional Institution in Cumberland, Md. Shereen Marisol Meraji/NPR hide caption

itoggle caption Shereen Marisol Meraji/NPR

Danny Trejo's big break came about partly because of a prison tattoo on his chest, depicting a woman wearing a sombrero. Thanks to that distinctive mark, a screenwriter recognized him as a champion boxer. Carlos Jasso/AP hide caption

itoggle caption Carlos Jasso/AP

Inmate dormitories at Louisiana State Penitentiary, like this one photographed in July 2011, have heating in the winter and cooling by fans and open windows in the summer, but no air conditioning. A judge ruled earlier this year that that constituted cruel and unusual punishment, but installation is on hold pending a state appeal. Scott Threlkeld/The Times-Picayune/Landov hide caption

itoggle caption Scott Threlkeld/The Times-Picayune/Landov

Marquise Lamberto Frescobaldi (right), of the winemaking dynasty, talks with prisoners Brian Baldissin (left) and Francesco Papa at his vineyard on Gorgona island in June 2013. Alessandro Bianchi/Reuters/Landov hide caption

itoggle caption Alessandro Bianchi/Reuters/Landov

In the Father to Child Summer Camp Behind Bars program, kids can bond with their fathers while staying at a campground near prison. Geray Williams, an inmate at the North Branch Correctional Institution in Cumberland, Md., gets a hug from his son Sanchez during the weeklong camp in 2010. Timothy Jacobsen/AP hide caption

itoggle caption Timothy Jacobsen/AP