The question needs to be asked, "Why has it taken so long for charges to be levied against these criminals?". Cambodians have been waiting for over 35 years for some kind of justice, and now in 2010 it appears that they may finally get some.
As reported by CNN, http://edition.cnn.com/2010/WORLD/asiapcf/09/16/cambodia.khmer.rouge.top.cadre.case/?hpt=T2, the U.N. backed war crimes tribunal has finally filed charges against 4 surviving Khmer Rouge cadre.
The hope is that justice will be served for the survivors of this atrocity. We will have to watch.