Two former Serbian intelligence chiefs were to go back on trial before a UN court Tuesday, accused of running death squads that terrorised Bosnia and Croatia in the bloody 1990s Balkans wars.
More than nine years after their original trial opened, Jovica Stanisic, 66, and Franko Simatovic, 67, are being retried on four charges of crimes against humanity and a war crimes charge after being freed in 2013.
Their acquittal before the International Criminal Tribunal for the former Yugoslavia (ICTY) unleashed a storm of protest and was overturned two years later after prosecutors appealed.
The two men were ordered to return to the tribunal in The Hague to face a retrial on the same charges.
Stanisic, the former head of Serbia's old state security service and a key figure in the regime of Slobodan Milosevic, and his deputy Simatovic now stand accused once again of organising, financing and supplying paramilitary groups.
These groups cut a swathe of terror and destruction across Croatia and Bosnia during the conflicts that erupted amid the collapse of Yugoslavia.
They included an elite unit dubbed the "Red Berets" and the feared paramilitary outfit run by Zeljko "Arkan" Raznatovic, called "Arkan's Tigers".
The death squads attacked towns and murdered Croats, Muslims and other non-Serbs to force them out of large areas, seeking to establish a Serb-run state, prosecutors alleged, as they called for life sentences for both men in the original trial which opened in 2008.
UN prosecutors maintain that Stanisic and Simatovic were part of a joint criminal enterprise that included the late Serbian president Milosevic and Bosnian Serb leader Radovan Karadzic.
An estimated 100,000 people died in the Bosnian conflict, which saw some of the worst atrocities in Europe since World War II, and during which 2.2 million people were forced from their homes.
The indictment alleges the joint criminal enterprise between April 1991 and December 1995 aimed for the "forcible and permanent removal of the majority of non-Serbs from large areas in Croatia and Bosnia and Herzegovina".
But the ICTY's trial judges said in May 2013 that although the Serbian units carried out the killings, Stanisic and Simatovic could not be held criminally responsible as they did not give the units specific orders to commit the crimes.
The trial judges also said there was not enough evidence linking the men to a joint criminal enterprise.
In a rare turnabout however, that judgement was quashed on appeal by the prosecution in December 2015, when the appeals court found that the trial judges had "erred" on several points of law.
Stanisic and Simatovic are among the last top Balkans officials still being held in The Hague and are being retried by a different UN tribunal wrapping up outstanding cases.