tarrangar
Fat arctic chicken
I see a quite simple solution, we execute the ones who murdered their slaves, if they didn't have slaves executed for anything less than the law saying they should execute them, then they wont get punished, but if they executed slaves for things the law don't say is an executable offence, then they get executed themselves.I see no real way around that.
UNless they are very, very good at taking that vengance, then they'll either get away with it without being caught (or even the murder identified as such), or someone higher up might take interest enough to recruit them.
As always, exeptions only for people doing PC-worthy deeds.
Basically we treat things as if every slave they killed was a freeman, and judge them according to that.