The Practical Guide to Humanitarian Law

« Calling things by the wrong name adds to the affliction of the world. » Albert Camus.

International Criminal Tribunals for the Former Yugoslavia (ICTY) and Rwanda (ICTR) and the International Residual Mechanism for Criminal Tribunals IRMCT)

I. Background

Following the armed conflicts in Rwanda and in the former Yugoslavia in the 1990s, and in the absence of a permanent international criminal court, the international community decided to establish two ad hoc International Criminal Tribunals entitled to prosecute individuals responsible for war crimes, crimes against humanity, and acts of genocide committed in these two specifics contexts. The International Criminal Tribunal for the former Yugoslavia (ICTY) operated from 1993 to 2017, and the International Criminal Tribunal for Rwanda (ICTR) from 1994 to 2015. Both tribunals investigated and punished the perpetrators of the most egregious crimes committed during these conflicts.

The United Nations (UN) Security Council (UNSC) set up both Tribunals through resolutions adopted under Chapter VII of the UN Charter. Such resolutions are binding on all States, and the Tribunals were established in this way so as to impose their jurisdiction directly on all States. They also imposed on all States an initial common definition of war crimes, crimes against humanity including ethnic cleansing and sexual and gender-based crimes as well as genocide. The other method would have been to adopt a treaty creating such a tribunal, but this was not possible because it would have required States’ consent and then ratification. Therefore, the UN did not opt for this option. The UNSC resolution was a quicker and more efficient way to enforce decisions on all States. It was also a clear signal that international criminal justice was seen by the members States of the UNSC as an instrument and being an integral part of the international peace and security agenda.

Since the establishment of these two Tribunals, the International Criminal Court (ICC) has come into being, obviating the need for additional ad hoc tribunals. On 17 July 1998, States adopted the Statute of the ICC, called the Rome Statute, which entered into force on 1 July 2002. The ICC is responsible for trying persons accused of genocide, war crimes, and crimes against humanity like those tried by the ICTY and the ICTR. Since 17 July 2018, the ICC also has the jurisdiction over the crime of aggression. The ICC’s jurisdiction is subject to certain conditions, and it only acts when the States or the State concerned are unwilling or unable to carry out the necessary investigations and prosecutions. However, the UNSC can impose the jurisdiction of the ICC on a particular State by adopting a resolution under Chapter VII of the UN Charter

Over the years of their existence, the two ad hoc international criminal Tribunals have contributed to the development of international jurisprudence on the interpretation of key concepts of international humanitarian law (IHL) in situations of international or non-international armed conflict. These elements will be discussed along with the presentation of the various IHL concepts in their respective sections below.

➔ Genocide; International ConventionsInternational Criminal CourtSecurity Council of the UNWar crimes/Crimes against humanity

II. Structure and Organization

Although independent, the ICTY and ICTR had organisational links that ensured unity and coherence in their judicial operations and increased the effectiveness of the resources allocated to them. Each Tribunal consisted of the judicial division, the Chambers and the Office of the Prosecutor and an administrative division, the Registry. Until 2007, the Tribunals shared the same Prosecutor and Appeals judges, after which each Tribunal began to employ separate prosecutors and separate Trial judges, as well as administrative units and budgets.

1. The Judicial division

The judicial division had 14 judges, who had to be of different nationalities. The judicial division was originally set up with one Trial Chamber for each Tribunal (three judges each) and a common Appeals Chamber (five judges). However, two new resolutions adopted by the UNSC, (resolutions 1165 of 30 April 1998 and 1166 of 13 May 1998), aimed at speeding up justice, added one Trial Chamber for each Tribunal.

•The judges were elected by the UN General Assembly, which, as is still the case with the International Court of Justice and the ICC, had to take into account the need for equitable geographical distribution and the representation of the world’s major legal systems. The judges were elected for four years and were eligible for re-election. They were chosen from a list of 22 names selected by the UNSC.

•The 14 judges would then elect the President of the Tribunal, who would also directly preside over the Appeals Chamber and appoint the remaining judges to the various Chambers. The Trial Chambers, once established, also elected their own Presidents. In February 2012, Judge Vagn Joensen of Denmark was elected as the last President of the ICTR and was re-elected in April 2013 to serve until the closure of the ICTR on 31 December 2015. Judge Carmel Agius of Malta was the last President of the ICTY, taking office on 21 October 2015 and serving until the closure of the ICTY on 31 December 2017.

2. The Office of the Prosecutor

The Tribunals originally shared the same Office of the Prosecutor. The Prosecutor was appointed by the UNSC, upon nomination by the Secretary-General of the UN, for a four-year term, renewable once. He or she had the rank of Assistant Secretary-General. On 15 September 2003, Carla Del Ponte of Switzerland was replaced as Prosecutor of the ICTR by Hassan Bubacar Jallow of The Gambia. In 2007, the UNSC decided to renew his mandate for four years, and he served in this capacity until the completion of the Tribunal’s work on 31 December 2015. On 1st January 2008, Serge Brammertz of Belgium replaced Carla Del Ponte as the Prosecutor of the ICTY and served until the closure of the ICTY on 31 December 2017. The staff of the Prosecutor’s office was appointed by the UN Secretary-General upon recommendation of the Prosecutors, each of whom was also assisted by a Deputy Prosecutor.

3. The Administrative division and budget of the Tribunals

The administrative division of the Tribunals was the Registry, headed by a Registrar. Each Tribunal had its own Registry, which was responsible for the administration and maintenance of the Tribunal. The Registrars were nominated to a four-year, renewable terms by the Secretary-General of the UN after consultation with the President of the Tribunal. The registry’s staff was also nominated by the UN Secretary-General, after consultation with the Registrar.

The ICTY spent 695 million US dollars in its first ten years of existence and the ICTR spent approximately 1 billion US dollars over the same period. The final budget of the ICTR for its liquidation activities in the fiscal year 2016-2017 was 2086 million US dollars (see UN General Assembly (UNGA) resolution 70/241). The final budget of the ICTY for the fiscal year 2016-2017 was 105 779 million US dollars (see UNGA resolution 72/257). The budgets of both Tribunals were primarily drawn from the regular UN budget, but the Tribunals also operated partly thanks to voluntary contributions from States. As a result, they often suffered from serious funding problems that hampered their activities. This was a particular problem for the ICTR.

Based on the budgets for the first ten years of existence of these Tribunals, some have calculated that the cost per indicted suspect averaged 4.3 million US dollars for the ICTY and 11 million US dollars for the ICTR.

At the peak of their operations, in February 2011, the ICTR employed approximatively 628 staff of77 nationalities, and the ICTY employed 988 staff members of 82 nationalities.

III. Jurisdiction and Sentencing

1. Subject Matter Jurisdiction (Jurisdiction Ratione Materiae)urisdiction Ratione Materiae) urisdiction Ratione Materiae )

Both Tribunals had the power to “prosecute persons responsible for serious violations of international humanitarian law” (art. 1 of both Statutes). The specific crimes over which they had jurisdiction are defined in detail in each of the Statutes (arts. 2-5 of the ICTY Statute; arts. 2-4 of the ICTR Statute). For both tribunals these crimes fell under the categories of acts of genocide, war crimes, and crimes against humanity. Within this framework, each Tribunal has added a specific type of crime to its jurisdiction, compared to the narrower interpretations of international law of the past:

•The ICTY has elevated the legal status of the crime of rape, as such, to that of a crime against humanity. This was a new legal feature. To this end, the ICTY’s Rules of Procedure and Evidence provided for measures requiring a lighter burden of proof in cases of sexual assault (rule 96 of the ICTY Rules of Procedure and Evidence) .

•The ICTR extended the notion of grave breaches of IHL to include situations of internal armed conflict. It based its charges on violations of article 3 of the Additional protocol II of 1977 (art. 4 of ICTR Statute).

☞ The ICTR set two very important legal precedents, one on rape and one on genocide, in the judgment rendered against Jean-Paul Akayesu (Case no. ICTR-96-4-T, Judgment, 2 September 1998). It was the first judgment of an international tribunal to find an individual guilty of genocide and rape, using the legal definitions of rape and genocide, on the one hand, and of serious violations of Additional protocol II to the Geneva Conventions, on the other.

In addition to the guilty verdict, the ICTR also set an important legal precedent by stating that rape can be an act of genocide. More details of the judgment can be found in the chapter on ➔ Rape

2. Personal Jurisdiction (Jurisdiction Ratione Personae)Jurisdiction Ratione Personae) Jurisdiction Ratione Personae )

Both Statutes were based on the principle of individual criminal responsibility (art. 7 of the ICTY Statute, art. 6 of the ICTR Statute). Under international law, this principle applies only to “natural persons” (individual human beings), and the Statutes insisted on the fact that their jurisdiction was limited to such persons (art. 6 of the ICTY Statute, art. 5 of the ICTR Statute). States (or corporate bodies) could therefore not be tried.

The Tribunals had the power to prosecute all persons accused of serious violations of IHL (art. 1 of both Statutes), regardless of their degree of responsibility. The Statutes are based on the provisions of the Nuremberg Tribunal.

•Any person who planned, instigated, ordered, committed, or otherwise aided and abetted in the planning, preparation, or execution of a crime within the jurisdiction of the Tribunals —whether a government official, military commander, or subordinate— was considered individually responsible for the crime and could be prosecuted (art. 7(1) of the ICTY Statute; art. 6(1) of the ICTR Statute).

•Neither the official rank of an accused nor the fact that he or she may have acted under superior orders are considered grounds for excluding criminal responsibility.

•In the case of persons of superior rank —whether a head of State or government or a high civil servant— their official position neither relieves them of their individual criminal responsibility nor mitigates their punishment (art. 7(2) of the ICTY Statute, art. 6(2) of the ICTR Statute).

•In the case of subordinates, the fact that they obeyed superior orders does not relieve them of individual criminal responsibility. However, superior orders may be considered as a mitigating circumstance, but only in cases where such orders did not leave the subordinate with any freedom of action or judgment (art. 7(4) of the ICTY Statute, art. 6(4) of the ICTR Statute).

•Furthermore, a superior will be held responsible for a crime committed by a subordinate, if the superior knew or had reason to know that the subordinate was about to commit such acts or had committed such acts, and the superior failed to take the necessary and reasonable measures to prevent such acts or to punish the perpetrators (art. 7(3) of the ICTY Statute, art. 6(3) of the ICTR Statute). In this respect, the Statutes reflected the provisions concerning the duty of commanders from the 1977 Additional protocol I to the Geneva Conventions (API, art. 87).

In the case of Boškoski and Tarčulovski (19 May 2010, para. 52), the ICTY Appeals Chamber clarified that, pursuant to article 1 of the Statute, the Tribunal was not limited in its jurisdiction to prosecute persons of a certain level of authority, which means that the subordinate role of an accused was legally irrelevant in determining his or her individual criminal responsibility.

  • Any person who planned, instigated, ordered, committed, or otherwise aided and abetted in the planning, preparation, or execution of a crime under jurisdiction of the Tribunals—whether a government official, military commander, or subordinate—is individually responsible for the crime and may be prosecuted (Art. 7.1 of ICTY Statute; Art. 6.1 of ICTR Statute).
  • Neither the official rank of an accused nor the fact that he or she may have acted under superior orders are grounds for excluding criminal responsibility.

3. Territorial and Temporal Jurisdiction (Jurisdiction Ratione Loci and Ratione Temporis)Ratione Loci and Ratione Temporis) Ratione Loci and Ratione Temporis )

•The ICTY’s jurisdiction covers the territory of the former Socialist Federal Republic of Yugoslavia. Its temporal jurisdiction covered all crimes committed since 1 January 1991, the date on which the UNSC determined that hostilities had begun. The tribunal’s jurisdiction was intended to end when the ICTY considered that hostilities have ceased. The ICTY did not consider the signing of the Dayton Peace agreement in 1995 to be the end of its activities, as violence and crimes continued in the territory of the former Yugoslavia, including with the 1999 attack on Kosovo by the Serbian army, which led to the indictment of Slobodan Milošević, President of Serbia and signatory to the Dayton peace agreement.

•The ICTR’s territorial jurisdiction covered the territory of Rwanda and of its neighbouring States, while its temporal jurisdiction was limited to a period of one-year, from 1 January to 31 December 1994. This limitation created tensions, as the competence of the ICTR covered the entire period of the 1994 genocide, but left a very small window of opportunity for trying possible war crimes and crimes against humanity committed in its aftermath, in particular by the new Rwandan regime and its army.

•The ICTY and ICTR “Completion Strategy” was developed in 2003 to enable both Tribunals to wind down their activities and complete their pending cases. The plan envisaged the completion of investigations, trials and all other work by the end of 2010. It was endorsed by the UNSC in resolutions 1503 (2003) and 1534 (2004). The deadline has been extended to take into account the late arrest of remaining fugitives and the completion of judgments in complex cases. The International Residual Mechanism for Criminal Tribunals (IRMCT) was established by the UNSC 1966 (2010) to take over and complete the work started by the two ad hoc International Criminal Tribunals (see infra , section V).

In the Bizimungu et al. case (ICTR no. 99-50-T, Decision on Defence motions pursuant to Rule 98bis , 22 November 2005, paras. 20 and 26), the Trial Chamber II of the ICTR gave a broad interpretation of its jurisdiction ratione temporis , arguing that even if the tribunal’s jurisdiction was limited to crimes committed in 1994 (art. 1 of its Statute), conspiracy to commit genocide was a crime of a continuing nature, as it is stated in the Nahimana et al. case (ICTR no. 99-52-T, Judgment , 3 December 2003, paras. 100-104 and 1044). Therefore, the Trial Chamber II held that evidence of acts occurring prior to 1994 could be used as evidence of crimes committed during the period between 1 January and 31 December 1994 (para. 26).

In the case of Nahimana et al. (ICTR no. 99-52-A, Judgment , 28 November 2007, paras. 313-314), the ICTR Appeals Chamber held that “it was the intention of the framers of the Statute that the Tribunal should have jurisdiction to convict an accused only where all of the elements required to be shown in order to establish his guilt were present in 1994.” Accordingly, the Appeals Chamber held that in order to convict an individual, it must be established that the acts or omissions of the accused which establish his responsibility occurred in 1994 and that the accused had the requisite intent at the time of those acts or omissions.

4. Penalties

Persons found guilty of serious violations of IHL were sentenced to terms of imprisonment. The Tribunals have not applied the death sentence. In the absence of an international criminal code, international law has not established a standard sentence determined for a given crime. Therefore, the Tribunals were subject to the general sentencing scales that existed at the time of the former Yugoslavia and in Rwanda (art. 24(1) of the ICTY Statute; art. 23(1) of the ICTR Statute).

Once a sentence had been pronounced, the term of imprisonment was served in a country designated by the Tribunal from a list of States that indicated to the UNSC their willingness to receive convicted persons (art. 27 of the ICTY Statute). The ICTR added the possibility of serving out the sentence in Rwanda (art. 26 of the ICTR Statute).


The ICTY completed its work in 2017 and rendered its final judgment on 29 November 2017 in the case of Prosecutor v. Jadranko Prlić et al.. Pending cases were transferred to the IRMCT which rendered the last judgment regarding crimes committed during the conflicts in the former Yugoslavia in the case Prosecutor v. Jovica Stanišić and Franko Simatović on 31 May 2023.


In total, the ICTY has issued indictments against 161 individuals and all cases are now complete. Of the 161 accused, 18 persons have been definitely acquitted, 93 have been convicted and sentenced and 13 cases have been referred to a national jurisdiction under Rule 11bis (10 to Bosnia and Herzegovina, one to Serbia and two to Croatia), 20 indictments have been withdrawn and 17 died before their transfer to the ICTY or their sentencing. The Tribunal has also concluded contempt proceedings against 25 persons. As of December 2023, two individuals remained fugitives in a contempt case with the arrest warrants for Petar Jojić and Vjerica Radeta still to be executed and this case was transferred to the IRMCT.

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The ICTR completed its work in December 2015 and the pending cases were also transferred to the IRMCT. In total the ICTR issued indictments against 93 individuals and conducted trials for 82 accused of which 61 have been sentenced, 14 have been acquitted, two have had the charges against them withdrawn and five died before judgment from the ICTR or their transfer to the IRMCT. In addition, 10 cases have been referred to a national jurisdiction (eight to Rwanda and two to France) and two individuals remain fugitives both are now under Rwandan jurisdiction (Ryandikayo and Charles Sikubwabo).

France has rendered judgments for both cases referred to it. In 2019, the case against Mr. Wenceslas Munyeshyaka was dismissed and in 2022 (Mr. Laurent Bucyibaruta was sentenced to 20 years of imprisonment by French courts. Out of the eight cases referred to Rwanda, the death of two were confirmed by the IRMCT (Phénéas Munyarugarama in 2022 and Aloys Ndimbati in 2023), three underwent trial in Rwanda, were all convicted and sentenced to life imprisonment (Jean-Bosco Uwinkindi, Bernard Munyagishari and Ladislas Ntaganzwa), one was arrested in South Africa in May 2023 and is expected to be transferred soon to Rwanda for this trial (Fulgence Kayishema) and two accused remained at large (Charles Ryandiyako and Charles Sikubwabo).

In 2012, the ICTR had transferred to the IRMCT the case of three high-level fugitives: Augustin Bizimana, Félicien Kabuga, and Protais Mpiranyas as well as the appeal in the case of*Prosecutor v. Augustin Ngirabatware , for which the judgment was issued on 18 December 2014. The Mechanism also heard an appeal in the Munyarugarama case against the decision to transfer his case to Rwanda and rendered it decision on 5 October 2012 where for the first time, it was held that decisions from the ICTR and ICTY were binding on the Mechanism.

Felicien Kabuga (the so-called financier of the 1994 Rwandan genocide) was the only remaining fugitive under the jurisdiction of the IRMCT and therefore the last one awaiting international judgment, with all other cases having been completed by the IRMCT (the death of two accused who were still fugitives was confirmed in 2020 (Augustin Bizimana) and 2022 (Protais Mpiranya) and the two last fugitive cases (Ryandiyako and Charles Sikubwabo) had already previously been transferred to Rwanda for trial. On 16 May 2020, after 26 years as a fugitive, Mr. Kabuga was finally arrested near Paris where he had been living under a false identity. His capture, at the age of 84, was the culmination of a decade-long international manhunt that spanned several countries located on different continents. On 26 October 2020, Mr. Kabuga was transferred to the Hague branch of the IRMCT in the Netherlands based on a request by the Defence, supported by the Prosecutor and the Registrar, to allow for further medical examinations to determine whether Kabuga could safely be transferred to the Mechanism’s Arusha branch in Tanzania for trial. In view of a Defence request for the appointment of medical experts to assess Kabuga’s fitness to stand trial, the Trial Chamber appointed three independent medical experts and held hearings on 31 May, 1 June, and 7 June 2022 to allow for the examination of three of the medical experts and submissions of the parties on Kabuga’s fitness to stand trial and to be detained in Arusha.

On 13 June 2022, the Trial Chamber found that the Defence had not established that Mr. Kabuga was presently unfit for trial but nonetheless, noted that he suffered from cognitive impairment, was in a vulnerable and fragile state, and required intensive medical care and monitoring. It was decided that Mr. Kabuga would remain detained at the Hague branch of the Mechanism and his trial finally opened on 29 September 2022 on charges of genocide, incitement to commit genocide and crimes against humanity.

On 6 June 2023, the Trial Chamber concluded that the mental health of Mr. Kabuga, rendered him incapable of participating in his trial but decided to continue the case through an “alternative finding procedure that resembles a trial as closely as possible, but without the possibility of a conviction”. This was unprecedented in international justice of highly controversial nature.

Then on 7 August 2023, the Appeals Chamber of the IRMCT ordered the suspension of the trial of Mr. Kabuga on the grounds that the suffers from senile dementia and indicated that the Trial Chamber had erred in inventing an alternative procedure that did not exist. The Appeals Chamber therefore remanded the case to the lower court “with directions to stay the proceedings indefinitely and to expeditiously address the issue of Kabuga’s detention on remand”. However, since then the Defence has been working in identifying an appropriate and willing State that would accept Mr. Kabuga for his provisional release.

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☞ The jurisdiction of the ICTY and ICTR was limited in time and space:*

•The Tribunals had the authority to try individuals accused of criminal acts, not States.

•The Tribunals operated in parallel with national courts, but the latter could request that the latter defer certain cases under investigation or prosecution to the Tribunals for judgment.

•Victims and States could not bring complaints directly to these tribunals.

•The Prosecutor alone could decide to open an investigation, either on his or her own initiative or on the basis of information received. Non-governmental organisations (NGOs), victims, witnesses, intergovernmental organizations, and States could all submit information to the Prosecutor.

•The Tribunals have adopted their own definitions of war crimes and crimes against humanity, combining the definitions contained in the Statute of the Nuremberg Military Tribunal of 1945 and those contained in the Geneva Conventions of 1949 and their Additional protocols of 1977.

•Neither the excuse of the official function of the accused nor the excuse of having obeyed superior orders can be useful to exclude individual criminal responsibility. •Penalties were limited to imprisonment. The death penalty could not be imposed. •The Tribunals depended on the judicial cooperation of States to ensure their effectiveness, which in turn required each State to adapt its laws to such cooperation.

•The jurisprudence of the Tribunals has clarified the interpretation of IHL.


IV. State Cooperation


The existence of the*ad hoc International Criminal Tribunals did not relieve States of their obligation to search for and prosecute the perpetrators of grave violations of IHL, as established in the 1949 Geneva Conventions. To function properly, the Tribunals required the national systems of justice are effective and cooperate with one another in criminal matters.

Although the Statutes of the Tribunals were adopted by binding UNSC resolutions, judicial cooperation between the International Tribunals and the national authorities required that each country adapt its laws to allow for such cooperation and to enforce the decisions of the international tribunals within its domestic legal system. This is particularly important for the execution of international arrest warrants and the production documents and witnesses. It should be noted that for the ICTR, the Chambers have issued some subpoenas for some witnesses to testify on behalf of the defence and for the production of some documents, but Rwanda’s failure to comply with some orders has not led to a report to the UNSC(pursuant to rule 7*bis A of the ICTR Rules of Procedure and Evidence ) to highlight this breach of international obligations, while this had been done in similar cases at the ICTY.

The ICTR has been faced with the important issue of non-cooperation of States in the relocation of the five acquitted (Mr. Bicamumpaka (deceased on 19 May 2022), Mr. Nzuwonemeye, Mr. Mugiraneza, Mr. Zigiranyirazo and Mr. Ntagerura all acquitted between 2004 and 2014) and four convicted released persons after serving their sentence (Mr. Nteziryayo, Mr. Muvunyi (deceased on 10 June 2023), Mr. Nsengiyumva and Mr. Sagahutu). Indeed, since their acquittal or their released and until December 2021, these individuals were forced to remain and reside in “safe houses” in Tanzania under the care and custody of the UN since no country had agreed to welcome them on their soil and these persons could not return to Rwanda for fear that they may face re-prosecution or other violations of their human rights due to the current political leadership in the country. Despite that the UNSC commended, on multiple occasions, Member States that had accepted the relocation to their territories of acquitted persons and released convicts who had completed serving their sentences have failed to make arrangements to welcome these eight individuals. Moreover, although the wives and children of these acquitted and released persons benefit from asylum or are citizens of France, Belgium, Luxembourg, Netherlands, Canada, and Denmark, these countries and all others have refused to allow the acquitted or released persons to re-join their families.

Following the closure of the ICTR, the responsibility for relocation has been handed over to the Mechanism who is now faced with finding a solution to this daunting problem. Indeed, the IRMCT has a duty to ensure the welfare of the acquitted or released persons pending their relocation and to enquire whether their life or liberty would be at risk upon relocation (In*Re. Andre Ntagerur a, Case no. ICTR-99-46-A28, Decision on Motion to Appeal the President’s Decision of 31 March 2008 and the Decision of Trial Chamber III of 15 May 2008 , 18 November 2008). On 5 December 2021, eight of the nine acquitted and released individuals were relocated with their consent to Niger from Tanzania following a relocation agreement dated 15 November 2023 between the IRMCT and Niger. Mr. Bicamumpaka had refused the relocation to Niger and had sought medical care in Kenya, where he passed away in May 2022.

However, only three weeks later, on 27 December 2021, Niger’s breached the agreement and issued an expulsion order for these individuals. The expulsion order was said to be based on “diplomatic grounds” with no further explanation given. Since then, the acquitted and released persons have remain under*de facto house arrest and have had their identity documents confiscated by the authorities of Niger. In response, the IRMCT has repeatedly ordered Niger to release them, but the government has ignored or defied these orders. In its 7 February 2022 decision, the IRMCT Duty judged summed up well the situation of non-cooperation from States and the impact on the eight concerned individuals: “What seemed to be a good solution to a longstanding problem related to the acquitted and released persons […] has now turned into a possible human rights violation and turned the rule of law and the norm where States adhere to treaties on its head.” ( François-Xavier Nzuwonemeye, Prosper Mugiraneza, Protais Zigiranyirazo, Anatole Nsengiyumva, Alphonse Nteziryayo, Andre Ntagerura, Tharcisse Muvynyi, Innocent Sagahutu , Case no. MICT-22-124, Decision on motions regarding the relocation agreement with Niger and order for transfer of the relocated persons to the Arusha branch, 7 February 2022, para. 20).

1. Relationship between the Tribunals and National Courts


This relationship is based on three principles:

  1. Concurrent Jurisdiction

The Tribunals and national courts had concurrent jurisdiction to prosecute persons presumed guilty of serious violations of IHL (art. 9(1) of ICTY Statute, art. 8(1) of ICTR Statute). This was particularly important for victims. As explained above, only the Prosecutor could initiate an investigation or prosecution, and victims could not claim damages before the Tribunals. Thus, individuals and NGOs could only file complaints or claim compensation—and victims could only receive reparations for the injuries they suffered—before national courts. In this respect, national judges played an essential role in the exercise of international jurisdiction.


  1. Primacy of International Tribunals

Although the jurisdiction was concurrent, both Statutes clearly established that the Tribunals had precedence over national courts (art. 9(2) of the ICTY Statute, art. 8(2) of the ICTR Statute). This meant that the International Criminal Tribunals could formally request national courts to submit to the jurisdiction of the International Tribunals at any stage of the proceedings. Their respective Rules of Procedure and Evidence set out the details of the deferral procedures.

This principle of primacy was an exception in international law and has not been reproduced in the Statute of the ICC whose jurisprudence remains secondary to that of national courts.

  1. Ne Bis in Idem


Ne Bis in Idem* is a well-established legal principle, both in general criminal law and in international law, according to which a person may not tried twice for the same offence (also known as the protection against double jeopardy). It is one of the main guarantees of due process, as set out in the International Covenant on Civil and Political Rights (art. 14(7) of the ICCPR). This fundamental right was reflected in the Statutes of the two Tribunals (art. 10 of the ICTY Statute, art. 9 of the ICTR Statute).

Thus, a person tried by one of the International Criminal Tribunals could not be tried again by a national court for the same crime. Similarly, the Tribunals could try a person for an act for which he or she had already been tried by a national court. However, there were exceptions to this general principle: the Tribunals could try the person again if “the act was characterized as an ordinary crime [in the domestic trial]; or the national court proceedings were not impartial or independent, or were designed to shield the accused from international criminal responsibility; or if the case was not diligently prosecuted” (art. 10(2) of the ICTY Statute, art. 9(2) of the ICTR Statute).

2. Obligations of State Cooperation and Mutual Judicial Assistance


All States were obliged to cooperate with the two Tribunals at all stages of the investigation and prosecution of a person (art. 29 of the ICTY Statute, art. 28 of the ICTR Statute). These obligations included complying “without undue delay,” with requests for assistance in gathering evidence, taking the testimony from witnesses, suspects, and experts, identifying and locating persons, and serving documents. States were also required to comply with requests from the trial chambers, such as summonses, subpoenas, arrest warrants, and transfer orders.

In order to facilitate the transfer of an accused by a State to these international tribunals, special arrangements have been made between international tribunals and States, bypassing the usual channels of extradition procedures and their associated legal obstacles.

State obligations also included the duty to contribute to the budget, to provide staff and, above all, to adopt concrete judicial and legislative measures in national law to implement the provisions of the Statute of the Tribunals and the resolutions establishing them. The goodwill of States was hence a crucial element in ensuring the smooth functioning of the Tribunals. This was particularly important because, unlike domestic courts, the Tribunals had no enforcement mechanism to back them up and no concrete provisions to punish a State that did not cooperate with the Tribunals or that did not amend its national legislation to incorporate the obligations stemming from the Statute.

NATO deployed a stabilisation force (SFOR) in the former Yugoslavia, but it did not have a police mandate to search for war criminals. Instead, its mandate stated that it could arrest persons indicted for war crimes if it came across such persons in the course of NATO activities. However, several commando raids launched for the sole purpose of arresting indictees seem to indicate that this mandate has been interpreted flexibly.

➔ Genocide </content/article/3/genocide-1/>__ ▸ International Criminal Court </content/article/3/international-criminal-court-icc/>__ ▸ Judicial guarantees </content/article/3/judicial-guarantees/>__ ▸ Mutual assistance in criminal matters </content/article/3/mutual-assistance-in-criminal-matters/>__ ▸ Peacekeeping </content/article/3/peacekeeping/>__ ▸ Rape </content/article/3/rape/>__ ▸ Responsibility </content/article/3/responsibility/>__ ▸ Security Council of the UN </content/article/3/security-council-of-the-un/>__ ▸ Universal jurisdiction </content/article/3/universal-jurisdiction/>__ ▸ War crimes/Crimes against humanity </content/article/3/war-crimescrimes-against-humanity/>__


V. The Tribunals’ Completion Strategy and the International Residual Mechanism for Criminal Tribunals (IRMCT)


1. The Tribunals’ Completion Strategy


The two International Criminal Tribunals did not have a universal jurisdiction, and their mandates were limited in time. In its resolution 1934 of 26 March 2004, the UNSC called upon the Tribunals to take all possible measures to complete their investigations by the end of 2004, to complete all trial activities at the first instance by the end of 2008, and to complete all work in 2010, in accordance with the Tribunals “completion strategy.” As these deadlines were not met, the UNSC, in its resolution 1966 of 22 December 2010, decided to establish the International Residual Mechanism for Criminal Tribunals to enable the Tribunals to complete their work on pending cases without being allowed to open new cases. The resolution establishing the Mechanism called on the ICTR and the ICTY to complete their work by 31 December 2014 and to prepare for their closure and transfer of cases to the Mechanisms. Both Tribunals experienced delays in completing their work, but as mentioned above, the ICTR closed its doors on 31 December 2015, and the ICTY closed its doors on 31 December 2017. Since then, all remaining work has been taken over by the Mechanism.

2. The International Residual Mechanism for Criminal Tribunals (IRMCT)


The IRMCT was established by UN Security Council Resolution 1966 (2010) to complete the work of the two*ad hoc International Criminal Tribunals. The UN Security Council created the Mechanism as a “small, temporary and efficient structure”.

Since its establishment, the IRMCT’s tasks have included hearing the remaining trials and appeals of the ICTY and ICTR, locating and apprehending the three remaining fugitives indicted by the ICTR, assisting national jurisdictions with requests related to the prosecution of international crimes committed in Rwanda and the former Yugoslavia, monitoring cases referred to national courts, enforcing sentences, protecting witnesses and victims, and preserving archives. As per the latest annual report of the IRMCT of July 2023, the Mechanism’s continuous and general temporary assistance included 367 staffs comprising nationals of 68 States.

This Mechanism is divided into two branches; the ICTR branch, located in Arusha, Tanzania which became operational on 1 July 2012, and the ICTY branch, located in The Hague, Netherlands, which started its work on 1 July 2013. In March 2012, the UNSC appointed Judge Hassan Bubacar Jallow, the Prosecutor of the ICTR, as the Prosecutor of the IRMCT. Prosecutor Jallow was succeeded by Serge Brammetz, former ICTY Prosecutor. The UNSC appointed Prosecutor Brammetz on 29 February 2016 and reappointed him for a second term on 26 June 2020 and a third term on 22 June 2022, with effect from 1 July 2022 until 30 June 2024.

In the UNSC resolution 1966 (2010) establishing the Mechanism, the UNSC decided that:

•The Mechanism “shall continue the jurisdiction, rights and obligations and essential functions of the ICTY and the ICTR” (para. 4);*

•The*Rules of Procedure and Evidence of the Mechanism and any amendments shall take effect upon adoption by the judges of the Mechanism (para. 6);

•All States shall cooperate fully with the Mechanism and take any measures necessary under their domestic law to implement the provisions of the present resolution and the Statute of the Mechanism (para. 9); and

•The Mechanism shall operate for an initial period of four years, and the UNSC “shall review the progress of the work of the Mechanism, including in completing its functions, before the end of this initial period and every two years thereafter, and further decided that the Mechanism shall continue to operate for subsequent periods of two years following each such review, unless the Security Council decides otherwise.” (para. 17).


The Statute of the Mechanism is organised and structured on the basis of the two Tribunals’ Statutes and*Rules of Procedure and Evidence .

•*Competence of the Mechanism (art. 1(1)): “The Mechanism shall continue the material, territorial, temporal, and personal jurisdiction of the ICTY and the ICTR as set out in Articles 1 to 8 of the ICTY Statute and Articles 1 to 7 of the ICTR Statute”, as well as continuing upholding the rights and obligations of the ICTY and the ICTR; •The Mechanism shall have the power to prosecute, in accordance with the provisions of the Statute, persons already indicted by the ICTY or the ICTR and any individual who knowingly and wilfully interferes with the administration of justice by the Mechanism; but the Mechanism shall not have the power to issue any new indictments against any other person (art. 1 (2) to (5));

  • Structure and Seats (art. 3): The Mechanism shall have two branches, one branch for the ICTY located in The Hague, Netherlands and one branch for the ICTR located in Arusha, Tanzania.
  • Organization (art. 4): The Mechanism will be comprised of one Trial Chamber for each branch and a common Appeals Chamber. The Prosecutor will be responsible for both branches. The Registry will also be common to both branches of the Mechanism and will provide administrative services for the Mechanism, including the Chambers and the prosecutor;

•Concurrent Jurisdiction (art. 5): The Mechanism shall have primacy over national courts and may formally request national courts to defer to its competence;

  • Referral of Cases to National Jurisdictions (art. 6): The Mechanism shall have the power to refer cases involving persons who are not among the most senior leaders suspected of being most responsible for the crimes covered by the Statutes of the ICTR and the ICTR to competent national authorities and shall monitor the cases referred. Competent national authorities are understood as the authorities of the country in whose territory the crime was committed, or in which the accused was arrested;
  • Roster of Judges (art. 8): The Mechanism shall have a roster of 25 independent judges, not more than two of whom may be nationals of the same State;
  • Election of Judges (art. 10): The judges of the Mechanism shall be elected by the UNGA from a list submitted by the UNSC;
  • The President (art. 11): After consultation with the president of the UNSC and the judges of the Mechanism, the Secretary-General shall appoint a full-time president from among the judges of the Mechanism.
  • Assignment of Judges and Composition of the Chambers (art. 12): The President shall appoint three judges from the roster to compose a Trial Chamber and the Presiding Judge from amongst their number to oversee the work of that Trial Chamber. In all other circumstances, including trials regarding interference with the administration of justice the President shall appoint a Single Judge from the roster to deal with the matter.
•Rules of Procedure and Evidence (art. 13): The judges of the Mechanism shall adopt Rules of Procedure and Evidence for the conduct of the pre-trial phase of the proceedings, trials and appeals, the admission of evidence, the protection of victims and witnesses and other appropriate matters.
  • Rights of the Accused (art. 19): All persons shall be equal before the Mechanism. In the determination of charges against him or her, the accused shall be entitled to a fair and public hearing, subject to article 20 and shall be presumed innocent until proven guilty according to the provisions of the present Statute.
  • Protection of Victims and Witnesses (art. 20): “The Mechanism shall provide in its Rules of Procedure and Evidence for the protection of victims and witnesses in relation to the ICTY, the ICTR and the Mechanism. Such protection measures shall include, but shall not be limited to, the conduct of in camera proceedings and the protection of the victim’s identity”.
  • Judgements (art. 21): The Single Judge or Trial Chamber shall pronounce judgments, rendered by a majority of the judges and impose sentences and penalties on person convicted by the Mechanism. The judgments and sentences will be delivered in public and accompanied by a reasoned opinion in writing.
  • Enforcement of Sentences (art. 25): Imprisonment shall be served in a State designated by the Mechanism from a list of States with which the UN has agreements for this purpose and the Mechanism shall have the power to supervise their enforcement.
  • Cooperation and Judicial Assistance (art. 28): States shall cooperate with the Mechanism in the investigation and prosecution of persons covered by article 1 of the Statute.


With the latest judgment from the Appeals Chamber in August 2023 on the*Kabuga case, the Mechanism has completed its ad hoc judicial activity for core crimes cases transferred by both the ICTY and ICTR. In 2024, it will become a truly residual institution, concentrating on carrying out its mandated ongoing functions, namely the protection of victims and witnesses, monitoring the execution of sentences, providing support to national jurisdictions by responding to their request for assistance, and preserving and managing archives, tracking the remaining fugitives (Charles Sikubwabo and Charles Ryandikayo), awaiting execution by Serbia of the two arrests warrant in the contempt case of Petar Jojićand Vjerica Radeta to begin their trial and will continue to monitor the remaining cases referred to national jurisdictions.

✎ United Nations Residual Mechanism for Criminal Tribunals


Arusha branch* : Haki Road, Plot No. 486 Block A, Lakilaki Area

Arumeru District

P.O. Box 6016, Arusha, Tanzania


Hague branch* : Churchillplein 1,

2517 JW, The Hague, The Netherlands


@International Criminal Tribunal for the former Yugoslavia: International Criminal Tribunal for Rwanda: United Nations Residual Mechanism for Criminal Tribunals:

Caselaw from the IRMCT, the ICTY and the ICTR can be found using these online resources: or

.. note:

For Additional Information:

Acquaviva, Guido, “Was a Residual Mechanism for International Criminal Tribunals Really Necessary?”,*Journal of International Criminal Justice , vol. 9, no. 4 (2011): 789-796.

Bassiouni, M. Cherif and Peter Manikas,*The Law of the International Criminal Tribunal for the Former Yugoslavia , Irvington-on-Hudson, NY: Transnational Publishers, 1996.

Beigbeder, Yves,*Judging War Criminals: The Politics of International Justice, London: Palgrave Macmillan, 1999, esp. 146-185.

Boed, Roman, “The International Criminal Tribunal for Rwanda”, In*Post Conflict Justice , edited by Cherif Bassiouni, 487-498. Ardsley, NY: Transnational, 2002.

Cryer, Robert, “The Ad Hoc Tribunals and the Law of Command Responsibility: A Quiet Earthquake” in*Judicial Creativity at the International Criminal Tribunals, Darcy, Shane and Powderly, Joseph, Oxford University Press, 16 December 2010, p. 159-183.

Darcy, Shane and Powderly, Joseph, J*udicial Creativity at the International Criminal Tribunals , Oxford University Press, 16 December 2010, 391 pages.

Della Morte, Gabriele, « Les Tribunaux Pénaux Internationaux et les références à leur propre jurisprudence : auctoritas rerum similiter judicatarum? »,*European Society of international law , 2018. Available at

Fometé Jean-Pelé and Roland Adjovi,*Les relations entre le Tribunal pénal international pour le Rwanda et les États : l’obligation de coopération dans l’exécution du mandat du Tribunal , Bruxelles : Bruylant, 2005, 180-196.

Human Rights Watch,*Genocide, War Crimes and Crimes against Humanity; A Digest of the Case Law of the International Criminal Tribunal for Rwanda , 2010.

Genocide, War Crimes and Crimes against Humanity; A Topical Digest of the Case Law of the International Criminal Tribunal for the Former Yugoslavia* , 2006.

Genocide, War Crimes, and Crimes against Humanity: Topical Digests of the Case Law of the International Criminal Tribunal for Rwanda and the International Criminal Tribunal for the Former Yugoslavia* , 2004.

International Committee of the Red Cross,*Ad hoc tribunals, 29 October 2020, available at

“International Criminal Tribunals.”,*International Review of the Red Cross , vol. 88, no. 861 (March 2006): 5-215.

Jones, John R. W. D. and Steven Powles,*International Criminal Practice, 3rd ed. Ardsley, NY: Transnational, 2003.

Kerr, Rachel,*The International Criminal Tribunal for the Former Yugoslavia: An Exercise in Law, Politics and Diplomacy, Oxford: Oxford University Press, 2004.

Korir, Issa, “Rwandan detainees face prolonged wait for transfer as IRMCT dismisses request”,*Journalists for justice , 21 August 2023.

Lepidi, Pierre and Bensimon, Cyril, « Au Niger, le sort embarrassant de sept Rwandais acquittés ou libérés par la justice internationale »,*Le Monde , 16 June 2023.

Lyons, Beth S., “Is the UN/International Residual Mechanism for Criminal Tribunals (MICT) washing its hands (again) of accountability and justice for the International Criminal Tribunal for Rwanda (ICTR) acquitted and released persons?”,*Blog Intlawgrrls: voice on international law, policy, practice , 6 June 2022.

Marcil, Alexandra. « Stratégie d’Achèvement des Travaux du TPIR par le Transfert des Accusés Devant les Tribunaux Rwandais: Peut-on Garantir le Droit à un Procès Équitable? »,*Revue Québécoise de droit international , Hors-série, 2010, 266-285.

Morris, Virginia, and Michael P. Scharf,*An Insider’s Guide to the International Criminal Tribunal for the Former Yugoslavia: A Documentary History and Analysis. Irvington-on-Hudson , NY: Transnational Publishers, 1995.

The International Criminal Tribunal for Rwanda* (2 vols.). Irvington-on-Hudson, NY: Transnational Publishers, 1998.

Mundis, Daryl A., “The Judicial Effects of the “Completion Strategies” on the Ad Hoc International Criminal Tribunals”,*The American Journal of International Law , vol. 99, no. 1,January 2005:pp. 142-158.

Quéguiner, Jean-François. “Ten Years after the Creation of the International Criminal Tribunal for Former Yugoslavia: Evaluation of the impact of its jurisprudence on international humanitarian law.”,*International Review of the Red Cross , vol. 85, no. 850 (June 2003): 271-311.

Scharf, Michael P. and Sterio, Milena,*The Legacy of Ad Hoc Tribunals in International Criminal Law: Assessing the ICTY’s and the ICTR’s Most Significant Legal Accomplishments , Cambridge University Press, 14 March 2019, 300 pages.

Spadaro, Alessandra. “International Humanitarian Law in the Jurisprudence of International Criminal Tribunals and Courts” in*The Companion to International Humanitarian Law , Djukić, Dražan and  Pons, Niccolò, Brill Nijhoff, 24 September 2008, p.135-153.

Sorel, Jean-Marc, « Les tribunaux pénaux internationaux : Ombre et lumière d’une récente grande ambition »,*Revue Tiers Monde , vol. 1, no. 205, 2011 : 29-46.

Tavernier, Paul, “The experience of the International Criminal Tribunals for the former Yugoslavia and for Rwanda”,*International review of the Red Cross, vol. 37, no. 321, December 1997: 605-621.

Tochilovsky, Vladimir,*The Law and Jurisprudence of the International Criminal Tribunals and Court: Procedure and Human Rights Aspects , Intersentia, Second edition, 19 March 2014, 1372 pages.

Wagner, Natalie. “The development of the grave breaches regime and of individual criminal responsibility by the International Criminal Tribunal for the Former Yugoslavia.”,*International Review of the Red Cross , vol. 85, no. 850 (June 2003): 351-383.

Wilson,*Ashby Richard, Writing History in International Criminal Trials , New York: Cambridge University Press, 2011.

Wippman, David. “The Costs of International Justice”, T*he American Journal of International Law , vol. 100, no. 4, October 2006, p. 861-881.

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