North Korea is facing the findings of a United Nations inquiry on human rights abuses in that country.
The commission of inquiry's report was formally presented at the UN Human Rights Council in Geneva.
A CNN reporter spoke with a former North Korean prison guard about what he witnessed.
Ahn Myeong-Chul's experiences would horrify you.
He was a guard in North Korean prison camps for eight years.
He talked about the day a pack of guard dogs broke free and attacked five children in the camp.
"We heard the screaming," he said. "By the time we got there three were already dead, bitten in the neck, one dog was eating the stomach of a child, the other two were bitten, but alive. They were all buried together. Two of the children were buried alive."
Ahn fled the country in 1994 after his father made a disparaging comment about the regime - his father committed suicide, the rest of his family was sent to a prison camp.
One former prisoner has drawn graphic pictures of life in the camps.
Ahn says the guards were given such intense ideological training by the regime, the prisoners were no longer human to them, they were like animals." He says that is how they were treated.
"Mass graves were common when there was an accident at one of the coal mines. In 1992 there was a measles outbreak, more than 400 people died including guards, they were all thrown in mass graves. Those executed are not even buried, their bodies are just left on the hillside."
Very few images of the prison camps have emerged - those that have escaped have barely done so with their lives let alone physical evidence.
Amnesty International has published satellite images which it says show the "vast infrastructure of repression."
The human rights groups believes hundreds of thousands of people are detained, but says it is unable to verify that.
Pyongyang denies the camps even exist.
The UN commission of inquiry is an unprecedented compilation of evidence on North Korea's human rights abuses which found ongoing crimes against humanity in the country and "unspeakable atrocities"
Even though Pyongyang refused to participate, Ahn believes this commission of inquiry could make a difference. He says contrary to popular belief, North Korea does in fact care about international criticism.