Between Pragmatism and Normativity: Legal Standards for Issuing Subpoenas and Witnesses Summonses in International Criminal Procedure

The article analyses the criteria that the international criminal tribunals developed to obtain additional evidence through witness testimony. It systemizes the legal standards of the ad hoc tribunals on subpoenas’ requests and reviews the International Criminal Court (ICC) stance on witness summonses. After defining the types of subpoenas and the different tests applied by the courts, the article examines the courts’ discretionary power in the light of the fair trial standard and the appellate standard for such discretionary decisions. The analysis shows that when the tribunal had to adjudicate a request to compel a witness to appear, it adapted the legal standard by considering the type and the object of the subpoena, the witness and the court’s role and mandate. The ICC iterated that this power to compel the appearance of witnesses constitutes a customary rule of international criminal procedural law. The article maps the content of this rule.