Criminal law translation questions/Fragen zur Übersetzung von Strafrechtsbegriffen

I reopened the comments on the February 12th entry, Questions on translating criminal law. That entry just collected some questions that had come up in a criminal law translation seminar in Frankfurt. Now I have received a further comment and posted it as anonymous (it came from a criminal court in Germany). But maybe the discussion should continue here.

Here are some queries from the comment: how to translate the following. I will come back to this in the next couple of days, I hope, when not dealing with Ludwig der Bärtige.

Anklageprinzip Offizialprinzip Ermittlungsgrundsatz Grundsatz der Mündlichkeit Grundsatz der Unmittelbarkeit?

Legalitätsprinzip: I objected slightly to mandatory prosecution because it sounds as if everyone had to be prosecuted. Suggestion in comment: mandatory investigation, because there has been some erosion of the term.

yes, I agree, mandatory investigation sounds good. It was the word mandatory we were considering in the seminar, not prosecution. The reason I didn’t like mandatory prosecution was because it sounded as if the public prosecutor simply has to prosecute everybody. What it really means, I would say, is that the prosecutor has to prosecute in certain circumstances (although, as the comment illustrates, there has been some erosion of the term. Still, if it was originally so named because prosecution was mandatory (albeit only if the investigation produced evidence), why not keep the name now, in contrast to the less mandatory Opportunitätsprinzip?