I saw this film as part of the Rotterdam Film Festival 2012, an impressive documentary about the Red Khmer (Khmer Rouge) in the years between 1975 and 1979. It gives us heavy food for thought, especially about shifting off responsibilities and the willing-less following of orders from above.
Rather early in the monologue held by our main character, called Duch for short, he confronts us with a few loaded sentences. For example: "It is better to kill one innocent man than to let a guilty one go", contradicting any judicial process as we know it. He also reads several quotes from Marx and Mao about (freely translated) sanitizing the population to eventually get a clean working class. He brought these book theories into practice to its full extent. Take for example that he recalls having not interfered after his grammar school teacher was captured and interrogated; otherwise he might have been accused of "individualism", that being nearly the worst you could say about someone.
He denies to have tortured or killed anyone, albeit he admits a few exceptions in the line of duty (he taught "interrogation techniques" as an officer). Another core statement is that everyone in the camps under his command is going to die but never too soon, in other words not until they got what they want.
His monologue is mixed with witness reports, partly contradicting Duch's statements, and partly underlining the horrible things that Duch talks about in very abstract terms. The latter is visualized by documents that Duch shows, with annotations in his handwriting, explicitly demonstrating that he ordered execution or "further interrogation". He also states to have never witnessed torture, but left that in the hands of subordinates. He only saw the reports, passed those on to central government when appropriate, or returned them to subordinates for further "processing", the latter augmented with instructions written in the margins. On the outside it looks not different from what we see in any bureaucratic organization, like a bank, where paper replaces things in the real world that the bureau worker never sees.
All in all, a memorable witness statement from both sides. It surpasses any Amnesty International report, in demonstrating how such cold killing machines can exist and how they operate. This topic is not tied to Cambodia, but applies world wide, and it already existed many centuries ago. It shows the underlying mechanisms, and how torturers and executioners are able to cope with this reality. Apparently, what they merely do it putting it on a higher level of abstraction. Or they categorize their victims as "bad" people (reasons for marking them bad depends on political context), who deserve this harsh treatment and eventually elimination.