For several years, Williams has also served as a member of international training delegations that have traveled to the International Criminal Tribunal for Rwanda (ICTR) in Arusha, Tanzania, and the International Criminal Tribunal for the former Yugoslavia (ICTY) at the Hague.
According to Marko Attila Hoare, a former employee at the ICTY, an investigative team worked on indictments of persons whom they labelled a ‘joint criminal enterprise’, including Slobodan Milošević, Veljko Kadijević, Blagoje Adžić, Borisav Jović, Branko Kostić, Momir Bulatović and others.
Three such courts are presently located at The Hague in the Netherlands: The International Criminal Tribunal for the former Yugoslavia (ICTY), the International Court of Justice (ICJ), and the International Criminal Court (ICC).
The ICTY accepted that the market place in Zenica was shelled by HVO on 19 April 1993 from the village of Putičevo, 15 kilometres from Zenica, killing 15 people and injuring another 50.
The Celebici Case: A Comment on the Main Legal Issues in the ICTY’s Trial Chamber Judgement, 13 Leiden Journal of International Law (2000) 105–138.
Ljajić was also the president of the National Council for Cooperation with the Hague Tribunal.
On July 29, 2005 chief ICTY prosecutor Carla Del Ponte filed motion for new trial, citing new evidence about Tihomir Blaškić's guilt.
The ICTY issued indictments against three senior Croatian commanders, Colonel General Ivan Čermak, Colonel General Mladen Markač and Brigadier (later General) Ante Gotovina.
Acting under Chapter VII of the United Nations Charter, the Council reaffirmed the necessity of the trial of those indicted by the ICTY and called for full co-operation from all states, particularly those in the former Yugoslavia, with regard to the arrests of Ratko Mladić and Goran Hadžić.
The resolution reiterated the importance of co-operation of all states with the ICTY and of the trial of all persons indicted, particularly calling for the arrest of Goran Hadžić.
United Nations Security Council Resolution 2007, unanimously adopted on September 14, 2011, after recalling resolution 1786 (2007) on the International Criminal Tribunal for the former Yugoslavia (ICTY), the Council reappointed Serge Brammertz as prosecutor of the Tribunal, countermanding the Tribunal's statute.