Watch part two

When the Khmer Rouge marched into the Cambodian capital of Phnom Penh in 1975 many thought peace had come to a nation torn apart by five years of civil war.

Instead, what followed was genocide. Until Vietnam toppled the regime in 1979, the Khmer Rouge and its leader Pol Pot turned on their own people, murdering more than two million in Cambodia's infamous killing fields.

Justice for the victims has been elusive but 30 years on, the first of five UN-backed trials involving Khmer leaders is finally underway and recently prosecutors have recommended that yet more should follow.

But the suggestion is controversial. 

Political division 

Hun Sen, Cambodia’s prime minister and himself a former Khmer official has warned that such a move could lead to further violence and unrest.

His opponents accuse him of interfering with the judicial process and trying to protect former rebels, some of whom are now members of his government.

Much depends on the success of the first trial which is now being televised to huge audiences in Cambodia.

The first Khmer official in the dock is Kang Guyk Eyoo, also known as Doik. He was head of a notorious prison, S-21, where thousands were sent to be tortured before execution. 

Samah El Shahat is joined in the studio by Brad Adams of Human Rights Watch.