A U.N.-backed tribunal in Cambodia trying former Khmer Rouge leaders over the 1970s genocide in the country upheld Thursday a lower-court sentence of life imprisonment against Khieu Samphan, the radical communist regime's former head of state.Thursday's decision was the final judgment of the Extraordinary Chambers in the Courts of Cambodia, which has adopted a two-tier trial system. With no one else being tried, it marks the end of the judicial process launched in 2006 to bring to justice perpetrators of the 1975-1979 reign of terror that is believed to have claimed nearly 2 million lives.K…READ FULL ARTICLE