The Conscience of Nhem En explores conscience and complicity in the story of a young soldier responsible for taking the ID photos of thousands of innocent people before they were tortured and killed by the Khmer Rouge.

Nhem En was 16 years old when he was the staff photographer at the notorious Tuol Sleng Prison, also know as Security-21 or S-21, where, from 1975 to 1979, 17,000 people were registered and photographed, then imprisoned and tortured, before they were killed.

The photographs of Tuol Sleng are an extraordinary document of madness and cruelty. In many cases, the prisoners were just opening their eyes, after a blindfold or hood was taken off, when the photographs were taken. Some appear oblivious to what is about to happen, reflexively smiling for the camera, but most seem very aware they are facing their death. Of the thousands of men, women, children, even infants, that Nhem En photographed, he did not aid or utter a single word of solace or kindness to any of them. He angrily defends himself when challenged about his part in the horror, saying everyone would do what he did to save their own lives. Only eight people are documented to have walked out of S-21 alive. Three of them tell their remarkable stories of survival. Bou Meng, 34 years old at the time, survived because the prison needed an artist to paint portraits of Khmer Rouge leader Pol Pot. Chum Mey, 42 at the time, survived because he could fix sewing machines. Chim Math, 20 years old, doesn't know why she survived, but she can't forget what happened to her.

Academy Award-winning filmmaker Steven Okazaki takes a moving and disturbing look at Cambodia, still recovering 30 years after the nightmare.