Drawings by an American in a Japanese prison

David Choe
"David Choe got arrested for punching out an undercover detective in Tokyo in December of 2004. Then he spent four months in solitary confinement in a Japanese prison. Deprived of his usual drawing and painting tools, David improvised materials out of whatever he could scrape together in his tiny cell, including soy sauce and his own urine." Link (NSFW)