Walker served as an army medic during the Iraq War, and by the time he returned home he had been on over 250 combat missions and developed PTSD and depression, for which he turned to heroin to cope. The drug habit led to a life of crime, which led to a stint in jail. He began writing his first novel, the semi-autobiographical Cherry, while serving an eleven-year prison sentence for a series of bank robberies in the Cleveland area committed in a four-month span. It soon became an unexpected phenomenon (“we were thinking maybe 1000 copies would be sold,” he remembers. The actual number is 100,000 copes in print.) and earned several accolades, including a nomination for the PEN/Hemingway Award. As a form of penance, Walker used proceeds from the book to pay back the banks he robbed.