Maybe it's a christian thing? He'll go to hell when he dies, and then the devil will keep him locked up for 10 more lifetimes. Then after that, he'll be free to roam hell or something. :p
Or, maybe they'll keep his rotting corpse in the jail cell for 10 more lifetimes after he dies, as a kind of "symbolic" imprisonment?
Yeah, I really can't think of a logical explaination. Anyone know? Thanks!