The International Criminal Court in The Hague, despite a high-minded ideal of attempting to bring dictators and those responsible for crimes against humanity on a grand scale, doesn't have the greatest reputation. It's not often that they're ever able to actually score a conviction. Not every nation buys into it, and those that don't are just as outside the court's jurisdiction as Boss Hogg is the second the General Lee crosses the county line... which allows the superpowers and those from many of the world's most brutal regimes convenient cover. The cases they've officially investigated, never mind any convictions, are exclusively African, leading to resentment from Africa that they're being picked on. (If you're thinking of Slobodan Milosevic dying prior to a verdict during his tribunal, that was not the ICC. That was a separate tribunal set up specifically for crimes committed in the former Yugoslavia, something done in the same general vein as the Nuremburg Trials. That tribunal is still open.)
And they've only scored two actual convictions... one of which just came down, on Germain Katanga, a warlord out of DR Congo, regarding an attack on the village of Bogoro in February 2003, where Katanga was found to have played a significant role in acquiring guns for a coalition of the Lendu and Ngiti tribes so as to more easily massacre the 200-some Hema residents; Bogoro is in a diamond-heavy region. Katanga was, however, acquitted of direct participation, as well as sexual charges that were also brought against him, to the chagrin of several Bogoro residents who distinctly remember having been raped and in at least one case made a sex slave by someone back in 2003.
Even the conviction they did get wasn't unanimous; the court uses a three-judge system and the conviction was a 2-1 decision, with Bruno Cotte (France) and Fatoumata Dembele Diarra (Mali) voting to convict, and
Christine Van den Wyngaert (Belgium) dissenting on the basis that the charges against Katanga were changed mid-trial (the trial began with him being tried as main perpetrator, and later downgraded to him being tried as a co-conspirator) and that he wasn't given sufficient opportunity to defend himself from the new charges.
Katanga, after he's sentenced next month, would not necessarily be actually serving his sentence in The Hague. The detention facility there is only meant for those whose trial process is still ongoing. The actual facility they do their time in is subject to an agreement between the court and the country in question, which doesn't necessarily mean they get shipped home. The other person convicted, Thomas Lubanga Dyilo, also of DR Congo, is in fact in The Hague. One of those convicted in a tribunal, though, Charles Taylor of Liberia, is serving his 50-year sentence (in his case, effectively life) in the United Kingdom; the identity of the exact prison he's in has not been made public. This is over Taylor's request to serve the sentence in Rwanda.
We'll soon see who's willing to take Katanga.