Legacy website of the International Criminal Tribunal for the former Yugoslavia

Since the ICTY’s closure on 31 December 2017, the Mechanism maintains this website as part of its mission to preserve and promote the legacy of the UN International Criminal Tribunals.

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The UN Security Council’s 1993 decision to create the Tribunal was a bold and innovative response to the conflict and crimes then taking place in the former Yugoslavia. But while the concise Statute provided by the Security Council was clear about the crimes over which the Tribunal had jurisdiction, there was little or no precedent to guide the practical work of the first such international court since the post-Second World War Nuremberg and Tokyo trials. The Tribunal's "pioneers" had to build a unique international criminal justice system practically from scratch.

When the first judges arrived at the Tribunal in November 1993, there were no rules of procedure, no cases and no prosecutor. Professional and qualified staff had to be recruited quickly and their often quite different experiences and methods of work from national systems needed to be merged into a functioning international criminal prosecution system. Both the Tribunal's opponents and its well-wishers were uncertain of its success.

By the time the first prosecutor arrived in August 1994, the judges had drafted the Rules of Procedure and Evidence, and the Deputy Prosecutor had set up the structures of the Office of the Prosecutor (OTP), recruited the first investigators and begun mounting investigations in what was, in some cases, hostile territory.

Investigating war crimes is not typical police work. The crimes that the OTP has to deal with were often massive events covering wide areas. Some took place over the course of many months and were highly organised. They involved regular soldiers, armed police, paramilitaries, politicians, and ordinary civilians. There are also many witnesses of different types, including victims and survivors, experts, internationals and insiders. The Tribunal was created to concentrate on the most serious crimes and the people most responsible for them. Wherever possible, investigations have therefore focused on the leaders who could be regarded as most responsible for the crimes, because even heads of state are not above the law.

The Early Years: 1993-1997

The first investigators faced a major challenge: the investigation of alleged crimes while the conflicts in Croatia (1991-5) and Bosnia and Herzegovina (1992-5) were still ongoing. The UN protection force (UNPROFOR) deployed in both of these states did not control security on the ground and often warring parties refused to permit Tribunal investigators access to reported crime scenes or witnesses.

In this start-up period, the OTP utilised and built upon the work of the UN Commission of Experts, a fact-finding body established by the Security Council, whose earlier work had demonstrated that serious crimes were being committed in Bosnia and Herzegovina (BiH), as well as Croatia. Information was also available from States and from a number of non-governmental organisations and humanitarian agencies who were operating in the region during the conflict. National and international media were another source of information. Nevertheless, it was vital for investigators to go directly to the victims and survivors to record their first-hand accounts by way of formal statements that would become the basis of evidence in court.

Many of the first available witnesses were victims who had fled from Bosnia and Herzegovina and found themselves refugees in other countries. They had been held in detention camps and had been the subject of "ethnic cleansing". Many had harrowing tales to tell of personal tragedy, suffering and loss. Most countries, however, lacked experience in cooperating with international prosecutors and investigators, and few legal mechanisms were in place. In the early years, the OTP therefore did a lot of work establishing the necessary legal agreements and sending teams of investigators to interview witnesses and to record their statements.

The Prosecutor personally invested much time and energy to build the credibility of the OTP and to obtain the cooperation of states. Many commentators in the international and diplomatic community were sceptical that the ICTY could function effectively or achieve results. In some parts of the former Yugoslavia, there was downright refusal to accept the legitimacy of the Tribunal, and clear obstruction of its work. Although in the establishment of the Tribunal there had been general agreement that there could be no lasting peace without bringing war criminals to justice, the reality of sharing information and coming forward to give evidence proved to be a stumbling block for many individuals and institutions.

It was important for the ICTY to demonstrate that international prosecutions were a reality. The first investigations centered on the reported widespread and horrific attacks on Bosnian Muslims and Croats in the Prijedor area of northwestern Bosnia, and the first case before the ICTY concentrated particularly on the notorious Omarska, Keraterm and Trnopolje Serb-run detention camps. Duško Tadić, the accused in that case, had been in custody in Germany and was being investigated there for similar crimes. The ICTY Prosecutor asserted the Tribunal's primacy over national courts and insisted on the case being transferred to The Hague.

Although the Tadić case was the first to go to trial, the first person to be indicted before the Tribunal was Dragan Nikolić, a commander in the Sušica detention camp in Bosnia established by Serb forces in June 1992. He was indicted on 4 November 1994. As the cases against Tadić and Nikolić would later prove, both were vicious men in the service of the Bosnian Serb authorities who tortured and murdered Bosnian Muslim civilians, but they were not part of the political or military leadership. Heavy expectations were placed on the Tribunal in these early stages of its existence to indict suspected perpetrators, but the institution was not then able to build up credible evidence to indict the leaders who masterminded the criminal campaigns. As a result, many of the early indictments were issued against relatively low and intermediate level alleged perpetrators whom eyewitness survivors and victims had identified as committing crimes in camps and similar locations. However, this so-called ‘pyramid’ approach, where low-ranking military and other officials are held to account for their actions, would over time enable investigators to build up cases against their superiors and ultimately the main architects of the crimes.

The Nikolić case highlights a major problem that would handicap the Tribunal for many years, but was especially acute in the early years: the Tribunal’s inability to arrest suspects and the deliberate obstacles placed in its path by some parties. Nikolić, indicted in 1994, did not come into the Tribunal’s custody until 2000. With the indictment of the Bosnian Serb military and political leaders Ratko Mladić and Radovan Karadžić in 1995, a consistent pattern of obstruction towards the Tribunal was established by Bosnian Serb authorities. They were not alone in their refusal to arrest and transfer suspects or meet their obligations towards the Tribunal. Both Croatia and Serbia obstructed the Tribunal’s work, with the authorities in Belgrade demonstrating the most consistent open hostility towards the ICTY.

The Tribunal’s indictment of Mladić and Karadžić less than two and half years after its establishment demonstrated how far the Tribunal had developed in investigating and building credible charges against military and political leaders. 

The conflicts in Bosnia and Herzegovina, as well as Croatia, concluded before the end of 1995. The following year, 1996, with peace in Bosnia and Herzegovina, was a significant year in the Tribunal’s history. The organisation was, for the first time in many cases, able to send investigators to alleged crime scenes. The most significant single development concerned the massive investigation into the events that took place in Srebrenica during and after the fall of the former UN ‘safe haven’ in July 1995.

Despite the denial of Serb and other authorities that any crimes had taken place, Tribunal investigators used the testimony of survivors, satellite photography, archaeologists, anthropologists, dog teams and a variety of other specialised teams and experts to search for evidence of mass executions and mass graves. The OTP’s investigations discovered dozens of mass graves, containing the remains of thousands of civilians, many with their hands tied behind their backs with wire, blindfolded with a rag and a bullet hole in the back of their head. The findings of the Tribunal’s exhumation programme that began in the summer of 1996 formed a critical component in the prosecution’s case against persons who were later tried and found guilty for their role in the genocide committed by Serb forces there. More than a decade later, national authorities are continuing the exhumation work with harrowing findings, while Mladić and Karadžić, indicted in 1995 by the Tribunal for their role in masterminding and overseeing the Srebrenica genocide, remained at liberty until Karadžić was arrested in July 2008.

Soon after the cessation of hostilities in the Bosnian conflict the international community requested in February 1996 that the Tribunal’s prosecution further assist peace-building efforts by performing an enhanced role in war crimes cases being processed before courts in Bosnia and Herzegovina. Under a system that became known as the Rules of the Road, an arrest warrant for a war crimes suspect before any national court in Bosnia and Herzegovina could only be issued after the case file had been reviewed and approved by the Tribunal’s prosecution. Case files were reviewed to determine whether they contained credible allegations and evidence or whether they were frivolous and unsubstantiated. The process played a major role in halting arbitrary and illegal arrests and promoting freedom of movement throughout the country. This ‘temporary’ arrangement was performed by the prosecution for more than eight years, concluding in 2004, when the process was transferred to competent bodies in Sarajevo.

By the end of 1996 the Tribunal had made impressive headway in issuing indictments against dozens of alleged perpetrators, but only a very few were held in the Tribunal’s custody. A NATO-led multi-national implementation force (IFOR) replaced the UN in Bosnia and Herzegovina, but they made it plain throughout their term that they would not seek out and detain suspects wanted by the Tribunal. It was not until the summer of 1997 with the establishment of the follow-on multi-national Stabilisation Force (SFOR) that the political climate changed and arrests were authorised. Contrary to the earlier fears of some military planners, the arrests did not trigger instability or turn local populations against international forces stationed in Bosnia and Herzegovina.

The change of strategy among the international community’s military force occurred roughly at the time when the prosecution adopted a tactic to enhance the likelihood of suspects coming into the Tribunal’s custody and limit their chances of going into hiding. Instead of publicly announcing each and every new indictment, the then Prosecutor Louise Arbour adopted a practice closer to that used in most national systems whereby the names of indicted suspects are not revealed to the media or other public agencies but are instead released only to select law enforcement agencies in order that they can detain the person for trial. The prosecution was able to engage the new-found willingness of SFOR and other international agencies to detain and transfer indictees by providing them with the names in so-called ‘sealed’ indictments. Numerous arrests followed. They were complemented by the so-called ‘voluntary surrender’ of many other accused fearful of arrest.

Maturity: 1997-2004

By the end of 1997, the Tribunal had reached a level of maturity that surprised many observers. It had demonstrated that international humanitarian law was not merely theory but could be effectively applied. The organisation continued to face many significant obstacles, such as the continued concealment of fugitives and evidence by certain states, entities and other agencies, but the prosecution continued to build upon and refine its investigation and indictment processes along with its expanding trial work.

The Tribunal's growing maturity coupled with its increased credibility opened up more opportunities for the prosecution in obtaining information and evidentiary materials. It also enabled the OTP to fix its sights on accused in the highest leadership positions rather than the immediate perpetrators and lower level accused that made up the majority of the early indictments. Investigators and prosecutors were assembling a huge collection of evidence of crimes. OTP analysts were developing a sophisticated understanding of the conflict, the chains of command, and the policies and objectives of the key players. International witnesses were prepared to give overview evidence of their experiences in dealing with people in power when crimes were committed. Many more so-called ‘insider’ witnesses stepped forward and were prepared to speak the truth, and hundreds of thousands of pieces of documentary, video and photographic evidence were collected.

The period from 1997 saw many precedents, both within and outside the Tribunal’s courtrooms. There were the first cluster of convictions at both the first instance and appeals stage, and there were convictions of perpetrators from all parties to the conflict in Bosnia and Herzegovina: Serbs, Croats and Muslims. The prosecution also witnessed its first failure to secure a conviction in the courtroom with judges acquitting an accused (Delalić, November 1998). Also, outside of the Tribunal’s control, the first death occurred of an indicted person resisting arrest by SFOR (Drljača, 1997). Another blow for the prosecution and the Tribunal as a whole was the suicide in the Tribunal’s Detention Unit of Slavko Dokmanović in June 1997. Dokmanović hung himself after the completion of the trial and on the eve of the verdict being handed down by judges.

A further negative matter impacting on the Tribunal’s work was the consistent refusal of Serb authorities in the Serb-dominated entity of Bosnia and Herzegovina, as well as the regime in Belgrade, to cooperate with the Tribunal. Not only did they conceal and withhold information but they refused to provide materials or any relevant information to Tribunal investigators endeavouring to investigate crimes allegedly committed against Serbs. Croatia’s cooperation was somewhat better but it, too, denied access to many crucial documents and refused to recognise the OTP’s mandate in relation to crimes allegedly committed by the Croatian Army against Serb victims in 1995 in the operations “Flash” and “Storm”.

In 1998 the prosecution faced a new challenge with the growth of violence in Kosovo. The armed conflicts in Croatia and Bosnia and Herzegovina had ended in 1995, and now, three years later, reports emerged that new crimes falling under the Tribunal’s jurisdiction were being committed. Hoping to contribute to a peaceful solution of the situation in Kosovo, the Prosecutor Louise Arbour made a public statement in March 1998 confirming that the Tribunal’s jurisdiction covered any serious violations of international humanitarian law taking place in Kosovo and that she was empowered to investigate such crimes.

The authorities in Belgrade, however, plainly refused any attempts by the OTP to investigate allegations of atrocities in Kosovo, arguing that it was an internal dispute with “terrorists”. Following a reported massacre of Kosovo Albanian civilians in Račak/Reçek in January 1999, Louise Arbour tried to enter Kosovo from the Former Yugoslav Republic of Macedonia (FYROM) but the Serbian authorities denied her entry at the border. Arbour was frustrated, but the event and her confrontation with the Belgrade authorities received significant publicity and assisted the Tribunal in its mission. Back in The Hague, Arbour stated unequivocally that she would investigate the Račak/Reçek massacre "with or without access to the territory".

The events in Kosovo would prove historic for the OTP in several respects. While the NATO bombing of the Federal Republic of Yugoslavia (FRY) as well as the violence on the ground in Kosovo were still ongoing, the OTP issued an indictment against the President of FRY, Slobodan Milošević. For the first time ever, an international criminal court had raised charges against a sitting head of state.

On 12 June 1999, Tribunal investigators entered Kosovo with NATO Kosovo Force (KFOR) troops. A few days later, forensic teams seconded to the Tribunal by member states began arriving in Kosovo to carry out exhumations of human remains from mass graves and scenes of crime investigations throughout Kosovo. The scale and pace of work was unprecedented. In 1999 alone, 2108 bodies were recovered from 195 locations. Temporary bases of operation were established in Albania, Kosovo and FYROM and thousands of witnesses were interviewed in a short period of time.

The Kosovo conflict presented the OTP with a new kind of scenario as NATO member states were a party to the armed conflict and therefore their actions potentially came under the Tribunal’s mandate. The OTP started receiving from various sources complaints and supporting materials concerning allegations that NATO personnel and leaders indeed might have committed crimes falling within the jurisdiction of the Tribunal during the NATO air campaign against FRY.

The Prosecutor considered it her obligation to review such complaints and allegations, and following a full consideration of her team’s assessment, she concluded that there was no basis for opening an investigation. Carla Del Ponte said that although some mistakes were made by NATO, she was satisfied that there was no deliberate targeting of civilians or unlawful military targets by NATO during the air campaign. The Prosecutor also considered that in this situation, quite unforeseen when the Tribunal came into existence, she should take the unusual step of making her reasoning public, and the OTP’s written assessment was therefore made publicly available.

> Read the Prosecutor's report on the NATO Bombing Campaign > Read Press Release from 13 June 2000

During the first years the focus of ICTY’s work had been on institution-building, but around the turn of the millennium, the Prosecutor had to start thinking of how to wrap up work one day, as the Tribunal had always been intended as an ad hoc body. The OTP couldn’t simply go on opening new investigations against countless suspects without considering when those cases could realistically be finished.

Soon after Carla del Ponte had assumed the post of ICTY Prosecutor in September 1999, she presented the first assessment of the completion of the OTP’s investigative mandate. In December that year she told the media that approximately 36 investigations, involving around 150 suspects, remained to be completed by the end of 2004. Later that indeed became the end date for investigations under the completion strategy endorsed by the UN Security Council, but some of the 36 investigations were discontinued along the way as the Prosecutor had to prioritise some cases over others in order to meet the deadline.

Furthermore, it turned out that crimes under the ICTY’s mandate had not ceased with the end of the Kosovo conflict. Following the outbreak of an armed conflict between government forces and organised Albanian rebel groups in FYROM in 2001, the ICTY Prosecutor decided to exercise her mandate to investigate allegations that war crimes had been committed by both sides in that conflict. The Tribunal’s exercise of primacy over those cases was contested by the FYROM courts and therefore a deferral hearing was held before a Tribunal Trial Chamber on 25 September 2003 to resolve the issue of primacy. As a result, five war crimes investigations before the national courts were deferred to the jurisdiction of the ICTY. One of them later resulted in an indictment before the Tribunal, the others are to be returned to the jurisdiction of the FYROM authorities.

A major landmark in the Tribunal’s history was the transfer of former Serbian and FRY President Slobodan Milošević to the ICTY’s custody on 29 June 2001, which Carla Del Ponte called “an important milestone for international criminal justice”.

The summer of 2001 saw also another historical development – the first genocide conviction before the ICTY. Radislav Krstić was found guilty of the genocide committed in Srebrenica, Bosnia and Herzegovina, in July 1995. This was a significant achievement for the OTP, as the crime of genocide is notoriously difficult to prove before a court of law. Attempts to prove genocide in relation to other parts of Bosnia and Herzegovina, such as Brčko or Prijedor, had failed in other trials.

In 2001, Carla del Ponte reorganised the focus of the work of OTP’s prosecution and investigation divisions by subordinating investigative resources to the needs of the senior trial attorneys with the goal of speeding up the preparation of indictments against high-level suspects and to better support the prosecution’s pre-trial, trial and appeal work.

Up until the year 2000, almost all of OTP’s indictments dealt with predominantly Bosniak victims. Among more than 40 indictments, the only exceptions were the early charges concerning Zagreb and Vukovar (Croat victims) and the Čelebići camp in Konjic, Bosnia and Herzegovina (Bosnian Serb victims) as well as the 1999 indictment against the Belgrade leadership for the crimes committed against Kosovo Albanians. The overwhelming majority of accused persons were of Serb ethnicity, plus a dozen of Bosnian Croats in a cluster of early indictments.

The Serbian and Croatian authorities repeatedly accused the OTP of ethnic bias and failure to recognise the suffering on all sides in the conflict. The prosecution had always asked that observers wait until all indictments are issued before levelling such allegations. Starting in 2001, the OTP’s investigations against senior leaders suspected of crimes committed against Croats and Serbs started to yield results and several indictments were confirmed for the Croatian operations Medak Pocket and Operation Storm, the atrocities committed by mujahedins in central Bosnia, the killings of Bosnian Croat civilians in Grabovica and Uzdol (BiH), and the crimes against Kosovo Albanian and Serb civilians committed by the Kosovo Liberation Army.

The years 2002-2004 were extremely busy for the OTP. Trial, pre-trial and appellate work increased dramatically, largely due to the introduction of ad litem judges which almost doubled the Tribunal’s capacity to hold concurrent trials. At the same time, the OTP was working under great pressure towards the deadline of end of 2004 to complete all investigations and to issue the last indictments. On a diplomatic front, the OTP worked hard to persuade states to comply with their international legal obligation to cooperate with the Tribunal.

The same period was also marked by a stream of guilty pleas, which helped ease the growing caseload. The OTP managed to strike plea agreements with as many as 14 accused between September 2001 and January 2004, reflecting the convincing evidence that had been collected against the individual accused. Biljana Plavšić became the first senior leader to confess publicly to her crimes. Some perpetrators, such as Milan Babić or Dragan Obrenović, provided invaluable information to the Prosecution and agreed to testify against other accused.

Completion: 2004 to date

The ICTY is a temporary ad hoc institution and for several years now it has been working towards a coordinated completion of its mandate, which also entails the transfer of evidence and cases back to national jurisdictions.

In December 2004, the ICTY Prosecutor signed the final indictments, the last of which were confirmed and unsealed in the spring of 2005. This was the first cut-off point of the Tribunal’s completion strategy. OTP’s focus could now turn more fully towards pre-trial, trial and appeal work. The aim is to complete trials as soon as possible after the end of 2010, and appeals within two years of that.

The confirmation of the final indictments finally ended speculation as to who is under investigation, who may be indicted and whether there are outstanding “secret indictments”. The crucial matter of outstanding fugitives nevertheless remained high on the agenda. The political support and pressure of the international community had always been important for the Tribunal, but the realistic prospects of integration with the European Union (EU) provided the strongest instrument so far for compelling the states of the former Yugoslavia to cooperate with the ICTY.

The EU’s decision to make ICTY compliance a condition for integration negotiations was instrumental for achieving unprecedented results in terms of arrests and surrenders. Within six months at the turn of 2004/2005, more than 20 accused were transferred to the Tribunal’s custody. Mid-2009, only two fugitives remained: Ratko Mladić and Goran Hadžić.

As the completion strategy target dates draw nearer, a number of measures are being taken to speed up the proceedings. Prosecution teams review and streamline their cases to try to reduce their length while focusing on the key charges against the accused. Sometimes the judges order the prosecutors to do so despite the OTP’s opposition. Prosecutors are making use of written evidence wherever they can instead of calling large numbers of witnesses to give live testimony. Cases are joined together wherever possible, and three trials were held with six or more accused on the dock. In July 2007, for the first time ever, as many as 26 accused were on trial simultaneously.

In the meantime, the OTP continues to conduct investigations in support of on-going trials and appeals. Even now, new witnesses are coming forward and new archives are opening up providing fresh evidence. Much of the Tribunal's evidence is now being shared with local courts, and a number of cases have been transferred for prosecution in the countries of the former Yugoslavia, especially to the War Crimes Chamber in Sarajevo, which was created largely thanks to the ICTY’s completion strategy. OTP staff helped in the process of setting up a dedicated war crimes section within the BiH Prosecutor’s Office and assisted in the difficult task of taking a case from one jurisdiction and adapting it for prosecution in another. Evidence and experience is continuously being passed on to national prosecutors in the region.

Eventually, however, the ICTY will shut down its operations. It is very unusual to be closing down an entire criminal justice system, but that is the exercise that the OTP and the other organs of the Tribunal will have to undertake in the coming years. For that reason, it is vital to obtain the immediate arrest of the last few outstanding fugitives. Only then will the prosecution of the top leaders be properly completed.

It is also important that political support for the successful completion of the Tribunal’s work remains strong. Over the years, the Prosecutor has made constant efforts to secure arrests, obtain evidence and generally maintain the level of cooperation and support among states and non-governmental organisations needed to bring cases to trial successfully. That kind of diplomatic work will continue throughout the final phase of the OTP's operations.

International criminal prosecution is now a reality. A tremendous amount of good work has already been done and the momentum must not be lost in the final years.