Hepatitis C virus, via transmission electron microscopy. (The actual viral diameter is around 22 nm.) Doctors say the recent FDA approval of Mavyret, a less expensive drug for treating the virus, may make it easier for more insurers and correctional facilities to expand treatment. James Cavallini/Science Source hide caption

Karriem Saleem El-Amin of Baltimore is one of the more than 130 prisoners serving life sentences for violent crimes who were released on probation following a landmark ruling by Maryland's highest court. Brandon Chew/NPR hide caption

Mentally ill prisoners too impaired to stand trial are supposed to be transferred to state mental hospitals for treatment within two or three months. But more than 300 in California are languishing in county jails because hospitals don't have the beds. Christian Schmidt/Corbis hide caption

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