Before investigations may begin, the jurisdiction of the Court with respect to a ‘situation’ must be triggered in one of three ways: a resolution of the United Nations Security Council, referral by a State Party and decision of the Pre-Trial Chamber authorizing the Prosecutor to proceed proprio motu. When the Security Council or a State Party refers a situation, the Prosecutor conducts a preliminary examination before deciding to proceed with an investigation. Should the Prosecutor decline to investigate, the Security Council or the State Party may apply for judicial review of the decision by the Pre-Trial Chamber. Special rules apply for triggering of jurisdiction over the crime of genocide by a State Party or by the Prosecutor. Pursuant to Article 16, the Security Council may temporarily block prosecution of a situation.

The Statute entered into force on 1 July 2002. Judges, the Prosecutor and the Registrar had been elected by mid-2003. After signing the Statute at the end of 2000, the United States moved to a position of hostility towards the Court, then became more mellow as it determined that its vital interests were not threatened. The Prosecutor developed a strategy of encouraging ‘self-referrals’, whereby Uganda, the Democratic Republic of the Congo and the Central African Republic sought the Court’s assistance in prosecuting anti-government forces. This led to the initial trials of rebel leaders from the Democratic Republic of the Congo. The Security Council referred the situation in Darfur, Sudan to the Court but provided no further assistance in apprehending suspects, including the President, Omar Al-Bashir. Using proprio motu authority, the Prosecutor undertook cases of post-election violence in Kenya and Côte d’Ivoire. For the first decade of its activity, the Court’s attention was essentially confined to the African continent. A malaise developed in Africa and a few African States attempted to withdraw from the Statute. By then end of the 2010s, concerns were being expressed about the future of the Court, with calls for major reforms.

The primary source of law before the Court is the Statute itself and the principal subsidiary instruments, the Elements of Crimes and the Rules of Procedure and Evidence. The Court may also refer to relevant rules of international law, notably those of international humanitarian law and international human rights law. Article 25 of the Statute sets out the various forms of participation in crimes starting with direct perpetration but also including ordering and forms of complicity and attempt. Article 28 defines so-called command or superior responsibility, by which an individual may be held responsible for crimes perpetrated by subordinates. The Court cannot prosecute an individual who was under 18 at the time of the crime. Statutory limitation of crimes within the Court’s jurisdiction is prohibited. There is a presumption that all crimes subject to the Court’s jurisdiction require proof of intent and knowledge. Several defences are codified: diminished mental capacity, voluntary intoxication, self-defence, duress and necessity, mistake of law and mistake of fact and, under limited circumstances, superior orders.

The International Criminal Court is a distinct international organization headquartered in The Hague. It works in close cooperation with the United Nations but is independent of it. The Court is composed of four ‘organs’: the Presidency, the Chambers, the Office of the Prosecutor and the Registry. The Presidency consists of the President and the two Vice-Presidents, who are elected by the Plenary of judges. Judges are elected by the Assembly of States Parties to terms of nine years; they must be nationals of a State Party. The judges are constituted into Divisions, for Appeals, Trials and Pre-Trial proceedings. Within each division may be one or more Chambers. The Appeals Chamber is generally composed of five judges while the other Chambers are generally made up of three judges, although a Single Judge may issue rulings in some cases. The head of the Office of the Prosecutor is the Prosecutor, who is elected to a nine-year term by the Assembly of States Parties. The Registrar is nominated by the judges but elected by the Assembly of States Parties and serves a term of five years. The Registrar is the principal administrative officer. The Court’s annual budget is proposed by its organs but must be confirmed by the Assembly of States Parties.

The Statute does not specify the penalty for specific crimes, leaving it to the Trial Chamber to fix a custodial sentence to a maximum of thirty years and, ‘when justified by the extreme gravity of the crime and the individual circumstances of the convicted person’, life imprisonment. Reflecting developments in international human rights law, the Court excludes any possibility of capital punishment. It may also impose a fine. The main objectives in imposing sentence are retribution and deterrence. Aggravating and mitigating factors are set out in the Rules of Procedure and Evidence. The convicted person may apply for early release after serving two-thirds of the sentence or, in the case of life imprisonment, after twenty-five years. Sentences are served in the domestic prisons of a State Party that has been so designated by the Trial Chamber.

International criminal justice began with efforts to prosecute Germans, including the former Emperor Wilhelm II, following the First World War. The first international trials took place at Nuremberg and Tokyo in the aftermath of the Second World War. In the early 1990s, the United Nations International law Commission submitted a draft statute for an international criminal court to the General Assembly. Subsequent work under the aegis of the Assembly culminated in the 1998 Rome Conference and adoption of the Rome Statute of the International Criminal Court. It entered into force in 2002. Meanwhile, several temporary international criminal tribunals were set up for situations in the former Yugoslavia, Rwanda, and Sierra Leone.

The Prosecutor begins by identifying situations for ‘preliminary examination’. A list of countries being considered for publication is published on the website of the Court. The Prosecutor reports annually to the Assembly of States Parties on the situations being considered at the preliminary examination stage. After deciding to proceed with an investigation, the Prosecutor applies for warrants of arrest or summonses to appear. When the accused appears before the Court, it may decide to allow interim release although detention during the proceedings appears to be the general rule. The case will not proceed for trial in the absence of the accused. The Pre-Trial Chamber must confirm the charges, following a hearing. The Pre-Trial Chamber also oversees the preparation of the case for trial, including disclosure of prosecution evidence to the defence.

An important role for victims is one of the innovations of the Rome Statute. Victims may participate in the proceedings at virtually all stages. They may even adduce evidence under certain conditions and make motions to the Court. The Court may also award reparations to the victims. Reparations may be paid directly by the convicted person or out of the resources of the Trust Fund for Victims. The Trust Fund may also use its resources to assist victims as part of its assistance mandate, which operates alongside the reparations function and in a manner independent of the criminal proceedings.

The procedural regime of the International Criminal Court is largely a hybrid of two systems, the adversarial approach of the English common law and the inquisitorial approach of the Napoleonic code and other European legislations of the Romano-Germanic tradition. The trial procedure is not specified in detail in the Statute or in the Rules, and a large degree of latitude to the judges in this respect. The trial is to take place at the seat of the Court, in The Hague, unless otherwise decided. In absentia trial is explicitly prohibited although the accused may be absent for part of the proceedings in certain circumstances. Subject to exceptions, the trial is public. Detailed procedural guarantees for the defence are set out, including a robust provision on the presumption of innocence. When the prosecution has finished presenting its evidence, the Trial Chamber may allow a ‘no case to answer’ motion. Special rules apply if the defendant chooses to plead guilty. Regulation 55 allows the judges to reformulate the charges while the trial is underway. When the trial is completed, the Trial Chamber may issue a decision convicting the accused if it is convinced of guilt beyond a reasonable doubt. Subsequent stages require the Trial Chamber to fix the sentence and then rule on reparations for victims. There is an unqualified right of appeal from the final verdict as well as appeals with permission of the Trial Chamber of decisions issued in the course of the trial, for example on matters of procedure and evidence.