So in my campaign, one of the players comes from a family of spies. This family is regarded as high nobility, and they're under jurisdiction of the government of the metropolis where they live. Yes, I know, having a well known spy family seems counterintuitive but that's the players backstory and I'm fine rolling with it.
The other part of the players backstory is that they're not well regarded by their own family, not having been able to follow in the family business of being a spy. I'm planning on a murder mystery happening where the player is framed for the murder of one of their own family members, and thus the family is going to apprehend them under their own jurisdiction instead of local law enforcement.
The other side of this is that the party, including the framed player, are all part of the city guard of the metropolis, and the chief (or whatever the title would be for the head honcho of a city guard is) of the city guard is aware that there's more to the situation than just a familial homicide, and send the rest of the party to apprehend the framed player first in order to save them.
How would this situation work out in terms of legal procedure? I know I can just handwaive everything, but I'm honestly curious now how this would work. Who has jurisdiction in a case that involves a large police department and the fbi or cia or whoever else is more apt for comparison to the situation at hand.
|Bob Bob Bob|
If the real world works anything like the TV world it starts with whoever gets their hands on them first. Then, if the other party can figure out who has them, they can request that a judge give them a court order handing over custody. Unless (and this is usually associated with the CIA) they just make the prisoner "disappear".
I think how it actually works (as it's a fairly rare conflict) is that the two agencies sit down and talk it out and usually hand over the person to whoever has a better case (or a longer available sentence). Then after processing (and possibly trying) them they hand the person over to the other agency to do the same.
Fantasy (medieval) politics are much different though. Generally anyone with authority is granted it by someone in power. The city guards probably derive their power from the local lord. The spies probably derive their power from the ruler. So between "in the name of the Marquis" and "in the name of the Queen" there's only one winner. Especially if the spies are nobility themselves, they may just be able to grab whoever they want in the name of the head of their house. Jurisdiction back in the day was just whoever could name-drop the best.
If you want the fantasy version to not end instantly it's as simple as having the local lord the same or higher rank than the spies. Since they're trying to take care of this "in house" as it were they're probably not going to invoke the ruler's authority. If the local lord is higher rank then it's sort of a cat and mouse game of when do the spies invoke the ruler's authority (since if they do it poorly they're abusing it) with a lot of behind the scenes investigating on both sides. If they're the same rank then it's a race against time while both wait for someone with a higher rank to come and arbitrate.
So short answer, in fantasy land it's whoever's backed by the biggest name. In the real world I think it just goes to the courts. But I can't think of any instance where one side wanted to protect them, it was always "who gets to try them first".