On-topic: This would be fun...
i suggest making it so that the criminal (if caught) has to be in a specified "jail" for one round.
Also, make the bodygaurds, since they are helping the criminal, able to be caught too, but they don't contribute to winning/losing if caught.
Off-topic: Heedi, ever read Montmorency? That thing you said about your underground tunnels and whatnot made me remember that book. =D