A complex verdict against Radovan Karadzic, found guilty of genocide at Srebrenica but acquitted of the same charge in other Bosnian towns, has again shown that the "most heinous" of crimes is the hardest to prove.
UN judges at the International Criminal Tribunal for the former Yugoslavia (ICTY) on Thursday found the former Bosnian Serb leader guilty on 10 charges of genocide, war crimes and crimes against humanity for his role in the 1990s Bosnian war.
With his conviction and 40-year jail sentence, some 15 people have now been found guilty of genocide at the ICTY for the 1995 Srebrenica massacre in which almost 8,000 Bosnian Muslim men and boys were killed.
But so far the charge of genocide in other municipalities has never succeeded at the ICTY.
"Genocide" was used for the first time within a legal framework at the Nuremberg military trials as the world vowed "never again" and prosecuted those behind the deaths of six million Jews in the Holocaust unleashed by Adolf Hitler's Nazi Germany.
Coined in 1944 by Raphael Lemkin, a Polish Jew, the term is derived from the Greek word "genos", for race or tribe, and the suffix "cide" from the Latin for "to kill".
Part of international law since 1948, genocide is now defined by the United Nations as an "act committed with intent to destroy in whole or in part, a national, ethnic, racial or religious group."
- 'Intent to kill ' -
In their complicated, technical ruling compiled into four volumes of more than 2,600 pages, the ICTY judges agreed Karadzic and his Bosnian Serb cohorts had "intended to kill all the able-bodied Bosnian Muslim males" in Srebrenica.
The judges also found that in other Bosnian towns and villages non-Serbs were subjected to persecution, murder, rape, forcible removal from their homes and detention in "terrible conditions."
But they were "not convinced" on the first count of genocide "that the evidence demonstrated that this amounted to conditions of life calculated to bring about the physical destruction of the Bosnian Muslims or Bosnian Croats in these municipalities."
ICTY chief prosecutor Serge Brammertz welcomed Thursday's judgement, saying "justice has been done" and told AFP his office may appeal the "not guilty" verdict once it has had time to read the massive ruling.
"It was one of the most important trials in the history of the tribunal," Brammertz told AFP.
While his office "would have preferred" a guilty verdict on both genocide charges, he stressed the judges had found that the "crimes in the different municipalities had qualified as war crimes and crimes against humanity" and Karadzic "has been convicted for murder, extermination and ethnic cleansing."
The ICTY, based in The Hague and set up in 1993 to prosecute war crimes arising out of the Balkans conflict, was the first international criminal tribunal to enter convictions for genocide in Europe.
A genocide verdict "has the potential of giving to the families the acknowledgement and recognition of this most heinous of crimes being committed against them and also recognising their suffering," American rights expert Eric Stover from the University of California, Berkeley, told AFP ahead of Thursday's ruling.
War studies expert Rachel Kerr, a senior lecturer at King's College London, agreed, saying "there's this perceived hierarchy of crimes. Genocide is the crime of crimes, and crimes against humanity are seen as somewhat lesser."
The fact that to date no-one has been found guilty of genocide in Bosnian municipalities "has been hugely problematic" for the tribunal.
- Never forgotten -
Genocide designations carry enormous moral implications and are often highly political, and even though the term is often bandied about, prosecutors and governments are more cautious about framing atrocities as such.
The United States only earlier this month declared that the Islamic State group's slaughter of Christians, Yazidis and Shiites in Iraq and Syria amounted to genocide.
And while the International Criminal Court in the Hague is the only permanent independent tribunal set up to try genocide, it is not yet established that it can act in Iraq or Syria since neither have signed the court's guiding Rome Statute recognising its authority.
Thus the ICC could only gain jurisdiction over crimes there via a UN resolution, which could be difficult to pass.
US ambassador to the United Nations Samantha Power issued an impassioned statement on Thursday's conviction.
Karadzic "believed he could do what he wanted, when he wanted, consequences to others be damned," she said, linking that violence to present-day brutality by Syrian President Bashar al-Assad, Boko Haram leader Abubakar Shekau and Islamic State group leader Abu Bakr al-Baghdadi.
"Today's verdict sends those leaders and others like them a message: your crimes will never be forgotten."