How Long Without Outdoor Exercise Is Too Long for a Prisoner in Solitary

WASHINGTON — Michael Johnson, a prisoner in Illinois, suffered from what the corrections system acknowledged was profound mental illness. That made him hard to handle, and prison officials responded by putting him in solitary confinement. Total isolation, in a windowless cell, made things worse. He hallucinated, compulsively picked at his skin and smeared himself with his own waste. He was often on suicide watch. And he violated countless prison rules, disobeying guards’ orders, spitting at them and damaging property. As a punishment for those violations, prison authorities took away his one sliver of solace: the hour of exercise that prisoners…