While living in Scotland, I always found the term 'Procurator Fiscal' rather funny. It sounds like a phrase from Gilbert and Sullivan's 'Trial by Jury'.

The thing about legal terms is that they have to be exact, and not open to misinterpretation. That results in rather complicated terminology and Latin bits and pieces, which trained lawyers understand perfectly well. It could be simplified into modern English, but that would leave it open to twisting and deliberately changing the intent etc.
We've made our Wills, and the wording sounds like something from Charles Dickens. But it makes the document watertight, and there can be no misunderstanding of our intents.

By the way, referring to Trial by Jury, I just love the line, "She could very well pass for forty-three, in the dusk with the light behind her." :) Brilliant!