Give the guy a LIFE SENTENCE, in a tiny little cell, with a mat for a bed, a diaper for his clothes, and a Quaran for his reading pleasure. Feed him just enough to keep him alive and figure out where you lost the key in about 40-50 years. PERHAPS exercise once a week if he ate all his gruel. Maybe maggot infested gruel is good enough, huh, since that is about all these Islamist's feed any American prisoner.
Martyrdom is WAY TOO GOOD for this radical Islamist.