The genocide trial of two senior Khmer Rouge leaders concluded its hearings on Friday with an angry scolding by the lawyer for one defendant and a humble bow to the victims by the other.

The half-day hearing could be the last in a decade of proceedings against leading figures in the four-year rule of the Khmer Rouge, the radical Communist movement that killed an estimated 1.7 million people in Cambodia from 1975 to 1979.

The defendants were Nuon Chea, 90, the ideologue sometimes known as Brother No. 2 who was second-in-command to the Khmer Rouge’s leader, Pol Pot; and Khieu Samphan, 85, the urbane, Paris-educated intellectual who served as the nominal head of state.

A verdict is expected to take months.