The list of alleged crimes includes murder, extermination, enslavement, imprisonment, torture, and willful killing, among others.
The welcomed proceedings marked the first substantial hearing for the three leaders, which has taken four years to bring them to trial.
Seng Theary said Wednesday the court had damaged the confidence of Cambodians in its ability provide justice.
The chamber judges were split on whether she should be released from detention or moved to a hospital under detention.
Three Khmer Rouge survivors will stay in Cambodia for one week to witness the first substantial hearing of the trial to date.
The Trial Chamber of the Khmer Rouge Tribunal said Wednesday that Nuon Chea is fit to stand trial, in proceedings set to begin Nov. 21.
Seng Theary had been a civil party complainant in both case 003 and 004.
Long Panhavuth, a monitor for the Cambodia Justice Initiative, suggested the UN side see itself as a “partner,” not as an “adviser.”
Another defense lawyer in Case 002, who requested anonymity, said the evidence does not form a link between the facts and the crimes.
Andrew Cayley, in an interview with VOA Khmer, addresses concerns in Case 003 and 004, following his lecture at Rutgers University.
Filmmaker Thet Sambath said his work has contributed a small part to the Khmer Rouge history.
Thet Sambath and co-producer Rob Lemkin answered questions from nearly 50 people in the audience after the film.