One thing I haven’t seen very much of in RPGs is actual ‘legal’ fallout from actions. I play in a Shadowrun game where police are regularly called in as response to player actions, but the gamemasters will just cut a deal with the PCs as the corporations that run the police only care about the bottom line of either being bribed or having the PCs doing a job. Then we have fantasy worlds where basically the same rules hold true. What ever happened to scenes like this court case from the First Knight movie where King Arthur puts Lancelot and Guinevere on trial for treason with their affair or the court case from Chrono Trigger where PC actions came back to haunt most players.
Many players may not like the idea of playing out a prolonged court battle or having their player be put in jail for extended periods, but these can be aventure hooks all on their own. Leverage, a tv show about criminals working as good guys, had an episode where the good guys helped fix a crooked trial to help innocent people and another where, with their mastermind on the inside of a prison, engineered an escape plan to get them out. Burn Notice also did an escape from prison episode at least once, if not more when you count villain lairs as prisons. So, even if you think that the capture of a PC is the end of things, it could be the start to something new like if you catch all the players you could have the TV series Oz which was on HBO and took place entirely in jail. Guardians of the Galaxy 1 had the main characters all meet up in a huge fight for an object and then have to work together to break out of jail, which got them working as a team, not a bad opening and better than you meet in a tavern. Escape Plan is a Schwarzenegger and Stallone movie about escaping from an inescapable prison.
Perhaps you could Phoenix Attorney a case for the players defense, if you really want to put your players on their toes as they try and figure a way to prove their innocence. This is like taking games like the CSI franchise and adding it to the Law and Order franchise and then figuring out what sort of arguments and the like the court is interesting in hearing. You could judge players based on their arguments or the rolls or whatever. For means of trial, you could get really creative such as done in the Vornheim City Kit where they come up with interesting options like
Trial by pie: The defendant and prosecutor have 24 hours to prepare as many pies (1 foot diameter) as possible. The accuser
then consumes any one of his/her pies as quickly as possible. The defendant must then consume any one of his/her own
pies as fast or faster. The accuser then must eat any one of the defendant’s pies as fast as that or faster, and then vice versa
and then the sequence starts over until one party or the other is unable to finish a pie in time (and therefore loses) or runs
out of pies (and therefore loses). The winner is entitled to any and all remaining pies.
If we’re looking at options for trials, magic can make some great abilities, as can technology in those that use it in place of magic. Discern truth spells or mind reading devices are such examples of how it can make legal systems reliant on them. However, at the same time, these things can be falsified either by those doing the readings or by those with knowledge of how it works. For example, Star Trek Voyager Ex Post Facto has one character reliving what the man he supposedly murdered saw, or in Deep Space Nine episode Hard Time where O’Brien was implanted with the memories of living in prison for years even though he had only been gone for a short time and now he had to cope with this. So, there are some ways that magic or technology can hep in these situations to make things easier, but they can also be ways that the guilty parties can make themselves much harder to find. The whole idea of Minority Report movie played on these facts and the Tv series of the same genre showed some ways how knowing too much about the future can change things.
Then we come to punishments. It might be easy to say ‘Let them rot in jail’ or ‘Let them do a quest to prove themselves’, however in other books like the Gamemaster’s Guide for Hackmaster, they have an eight page discussion on legal systems and crimes. Skipping their breakdown of crimes. as crimes are up to the Gamemaster, the types of punishments range from monetary and confinement to degradation like the scarlet letter or some activity or action to make them stand out, such as dunking, tar and feathering, pillory, etc. Torture could be a great punishment as it should give the person a reason not to want to do it again, as would Mutilation like removing hands of a thief or decapitation. Banishment and Slavery could be used to get ride of the undesired people or make them do some great effort to make reparations.
Assuming the punishment is not death, then things can get really interesting for the players as they need to find ways to live with these punishments. Are they having to deal with lost limbs or something that impairs the physical actions they can do? They’ll need to figure out a way to help cope with it, perhaps seek out someone to get a replacement, such as a magically enhanced prosthetic limb. If it is something more like nightmares that won’t let them sleep or feeling they’re being watched or anything else that could realistically give their character mental problems, it may be hard to figure out how to work with those for some people. It can add an edge to a character and may not be one they are happy trying to portray, but at least make sure to make use of it every so often, throwing a reference to how they haven’t felt that way since their time in prison or ‘That guy looks like the guy from your cellblock” or even something like “We would like to provide you with the details, but we were made aware that one of your party is a criminal”. Maybe the guards keep a watch on them as they go through town, making it harder to do things under the radar. There are many ways to make a criminal record matter.
A little time thinking over these sorts of topics and you’ll be able to come up with ideas as ways to make it more interesting for the players. The key is that you want it to be roleplay oriented and influenced. Have them try to play out as much as they can, have them interact with the scene and be there to push the developments beyond just passively rolling dice. I like to think of the law and order type scenes like the court scenes in Daredevil on Netflix, it is to add some alternative ways to push the story forward and make it interesting to watch and interact with. If you look at games like Devil’s Attorney phone game which is a click and choose ‘card’ game versus games like the Law and Order series where you interact by objecting against and choosing questions to ask to the witnesses, there are different ways the players will be connected to them, with the first being a mathematical connection not caring so much about story while the second is more involved because the player more purely shapes the events. Maybe something more akin to the court scenes from Star Trek: The Next Generation where humanity was put on trial and then, if you believe the ending, used the acts over the seven years of the show to prove if they were worth saving. Bookends to the series, makes a great adventure mark.