And is the ICTY run on an inquisitorial or an adversarial system?

I checked the statute.

ICTY - TPIY :: Statute of the Tribunal

Updated Statute of the International Criminal Tribunal for the former Yugoslavia:

September 2008 (PDF format)

It's a long pdf and my result is simply that I do not know, I think I lack the legal background to sniff out the key sentences. It would appear that the court has had some room to decide its own procedures, which might mean some mix considering the mix of judges.

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