26. The Appeals Chamber is satisfied that the Trial Chamber correctly found that defence investigators benefit from the same protections as defence counsel under Article 30(4) of the Statute of the Tribunal.[1] Article 30(4) of the Statute provides that:

[o]ther persons, including the accused, required at the seat of the […] Tribunal shall be accorded such treatment as is necessary for the proper functioning of the […] Tribunal.

27. The Appeals Chamber considers that defence counsel fall within the category of “other persons” required at the seat of the Tribunal to defend the accused. Accordingly, pursuant to Article 30(4) of the Statute, they are to be provided such treatment as is necessary for the proper functioning of the Tribunal.[2] Defence investigators, who facilitate the performance of the duties of defence counsel, have a derivative right to such necessary protections via the defence counsel. If such treatment is not extended to defence investigators, defence counsel’s ability to represent the accused may be frustrated.[3]

28. The Appeals Chamber finds, however, that the Trial Chamber erred in finding that defence members do not enjoy functional immunity from legal process under Article 30(4) of the Statute, that is immunity from legal process “with respect to words spoken or written and acts done by them in the course of the performance of their duties as [defence members] before the Tribunal, in order to allow for the proper functioning of the Tribunal in accordance with Article [30] of the Statute.”[4] In particular, it erred in concluding that the absence of an explicit reference to the Vienna Convention on Diplomatic Relations and the UN Convention on Privileges and Immunities from the text of Article 30(4) of the Statute indicated that defence members were denied functional immunity.[5] […] Instead, the Trial Chamber should have focused on what protection was “necessary for the proper functioning of the […] Tribunal” pursuant to Article 30(4) of the Statute. [T]he Appeals Chamber finds that the relevant question is whether functional immunity for defence members is “necessary for the proper functioning of the […] Tribunal”, not whether another treaty or Security Council Resolution provides for such immunity.

The Appeals Chamber further found that in this context, the Trial Chamber failed to properly consider the fundamental differences between a domestic court and an international criminal tribunal:

31. […] The Appeals Chamber considers that members of the defence working in an international criminal court operate in a different legal environment than those working in domestic criminal courts. Finding and interviewing witnesses, conducting on-site investigations, and gathering evidence in a State’s territorial jurisdiction may be more difficult without the grant of functional immunity, as there is always a risk that a State could interfere by exercising its jurisdiction in such a way as to impede or hinder the activities of the defence.[6] Permitting freedom of action in these situations by virtue of a grant of functional immunity protects individuals before the Tribunal in a manner unnecessary in domestic courts, where individuals can rely upon the State’s judicial apparatus and other entities to protect their ability to perform their functions in a criminal trial.

33. The Appeals Chamber accordingly finds that members of the defence, including defence investigators, enjoy functional immunity under Article 30(4) of the Statute with regard to acts that fall within the fulfilment of their official functions before the Tribunal due to their functions being “necessary for the proper functioning of the […] Tribunal”. Failure to accord functional immunity to defence investigators could impact upon the independence of defence investigations, as investigators may fear legal process for actions related to their official Tribunal functions.[7]