I am having a legal case in a fantasy bronze age Hammurabi's code style civilization go on in the background of the plot of a novel. I'm working on. Any pitfalls you think I should be careful of?
Bronze age societies are extremely diverse, and in a fantasy setting could be even more diverse, and that's a blessing and a curse for you, because it means you can kind of do what you want, but it also means you've got less structure to work with,
I think the main pitfall to avoid is assumption.
Assuming that because legal systems you're familiar with function in a certain, historical legal systems were similar or analogous to that.
The best way to avoid assumption is to ask why about every part of the legal system you're presenting, and then how that part was created and his maintained.
Like, if you're think there will be a full-time judge who does nothing but judge, then the question is why, in this society, does this guy exist? What caused them to have full-time judges? Is it the whim of a ruler who is aping a different civilization who have a better reason to have full-time judges? Is it because of the sheer volume of legal cases? The size of the society - we had bronze age societies with millions of people in them so it's certainly not impossible.
Fruit of the poison tree is an example here - it's a deeply bizarre legal concept, but for some people it's the whole "Fish don't know what water is" - it's just part of how they think laws work - they never ask why. But if you do ask why a society would have that concept, it really starts to break down interestingly - it's basically a libertarian/anarchist (in the philosophical sense) conceit that's about protecting people from the government and it's agents going through their stuff, even if it's at the cost of justice. That raises a whole bunch of other whys as to how society got like that - it suggests a society that's highly legalistic (i.e putting the letter of the law ahead of the "right thing" happening), a society where individuals have a lot of rights (which is not really a big concept in the bronze age, generally - some rights/responsibilities sure, but rarely to that extent), a society where the government has limited power, and so on.
How matters too - with full-time judges, for example, how are they chosen, how are they recompensed, who do they report to, are they appointed, elected, hereditary? If they're appointed, on what basis and by whom? If they're elected, what does that say about society? Usually it suggests a society which had trouble with or concern tyranny from above, so wants to prevent powerful people picking judges, but elected judges tend to be highly corrupt in favour of the core group who elected them, and if they're not elected for life, will necessarily tend to act to curry the favour of their electorate, which is likely to conflict with justice, especially for outsiders or minority groups who didn't or couldn't vote for them. Hereditary judges I can't think of a real world example of, but it might be interesting to think about the fantasy consequences of those.
Sorry I could go on all day - but the main thing is to not make assumptions, and question what you're putting down as how something works.
I would say generally probably avoid tropes like reams of evidence, trials that go on a long time (which basically never happened unless it was a show trial, until the 20th century), generally avoid legalism (i.e. loopholes, technicalities, and so on, a very tempting plot device) unless the society is a profoundly legalistic one somehow (but that kind of necessitates widespread reading and access to a written law base), and avoid exact replications of the whole judge, jury, prosecution, defence, witnesses, evidence setup.
Consider who has access to justice too - it's unlikely to be equal/egalitarian, even in a relatively well-meaning society. Do lawyers even exist? Probably not is usually the answer, but there may well be more erudite or well-spoken people who either speak for their friends/allies or can be hired. Is the law even written down? If it is, is that all of it? Is what's written down actually the law, or are those just ideals/goals? Does caselaw exist? Does precedent matter? And so on.
I'd also say embrace Wikipedia - it's a great starting point, and you can often find some interesting stuff in it about the histories of various legal concepts, and remember you probably have 100 free articles per month on JSTOR.
Back on to Star Trek, I'm finally caught up, so recent episode brief reviews:
Ep. 5 Charades - What a TNG episode. Fairly pointless, I felt. Not bad though - a lot of little funny bits, some nice characterisation of several characters, but it didn't have anything particularly meaningful to say nor drove any particularly strong characterisations. I did enjoy that some super-advanced civilization had what amounted to a call centre and they were trying to get through to second-line tech support to fix their friend.
Ep. 6 Lost in Translation - Another TNG episode. Dragged a bit at times. Didn't really enjoy Kirk this time. Nice to have more Uhura but it felt a bit random the aliens picked her - they tried to be all "Oh you have empathy and stuff", but like, it picked some rando engineer before that, so it rang a bit false. Also this showed a genuine failing of Star Trek - this is about the bazillionth episode which is essentially "Be careful about resource extraction/climate change/etc.", which is an important message, but like most of them, it relies on magic aliens magically telling us to stop being bad. How about more where people actually work this out rather than being told? I feel like a better story would be convincing skeptical people to stop doing an advantageous thing.
Ep. 7 Those Old Scientists - Very silly, quite fun, though the Orions were handled REALLY WEIRDLY, like, the desperately don't want to be seen as space pirates, but they are space pirates, what's going on here. It felt more like a story that Boimler and Mariner might have concocted to mollify Tendi than actually what happened.
Ep. 8 Under the Cloak of War - Ohh, a DS9 episode! Love the whole M'Benga/Chapel double-act, though I feel like Chapel is getting almost overused this season. The "plot twist" was perhaps excessively obvious, and for god's sake SFX guys, show as us some beam-type phasers/disruptors again, stop trying to make everything into a bloody machinegun, but the vibe of the episode, especially the flashbacks, was pretty strong ("TRANSPORT INCOMING" as people have pointed out was used very efficiently to traumatise the audience). I'd say the ending was an annoying cop-out, and frankly a little cheap for a Starfleet officer to be saying to their captain (like, you can say that if you're Major Kira, ex-space terrorist, talking to Sisko, not so much this situation), and it veered dangerously near the "HARD MEN MAKING HARD DECISIONS" mega-bollocks that Star Trek has, up to now, unequivocally and fiercely rejected (and must reject, I would say, it's antithetical to all decency). But the whole analogy/fritzing machine thing and that fact that a major lie was involved suggests we haven't heard the last of this, so I guess we'll see how it turns out (albeit maybe not for a while).
(Certainly might explain why M'Benga is more junior in the Kirk era if more of this comes out and/or M'Benga becomes more troubled by his own actions.)