My wife and I recently returned from our belated honeymoon in Cambodia. It’s a fascinating place, filled with beautiful landscapes and wonderful people, but it’s still laboring to escape one of the greatest calamities of the 20th Century.

In April 1975, the Khmer Rouge – a radical faction of a one pan-SE Asian communist movement – stormed into Phnom Pehn. Over the next three-plus years (until the Vietnamese rolled in), the Khmer Rouge regime embarked on a brutal plan of forced ruralization to complete their revolution. Anyone seen as a dissident or potential traitor was killed. Starvation swept the countryside. Millions died, although the exact number will never be known.

Enemies of the People is a film by Thet Sambath, whose mother, father, and brother were all killed by the Khmer Rouge. Earlier this century he spent years gaining the trust of a small group of Khmer Rouge functionaries and getting them to talk about what they had done. A few were the lowest level foot soldiers, the ones who did the actual killing. But the big target was Nuon Chea, also known as Brother Number Two, the Khmer Rouge’s second in command. After years of rapport building talks, he finally confesses to ordering the killing (along with Pol Pot, aka Brother Number One).

The film is thus both about how a victim of the Khmer Rouge has come to terms with this history, but also how the killers themselves have done so. Unlike the subjects in the similar film from last year, The Art of Killing, the responsible parties here all express regret for what they did. Perhaps understandably, the ones who did the actual work – which they relate in horrifying detail – are the most contrite. Nuon Chea himself is sympathetic (particularly after Sambath reveals his family’s history), but still clings to some ideology that suggests it was something he had to do for the sake of the nation.

A formal apparatus for dealing with the Khmer Rouge’s crimes didn’t arrive until the Extraordinary Chambers in the Courts of Cambodia were formed in 1997 (the post-Khmer Rouge unrest in the country didn’t end until 1998). Progress at the court has been slow and both of our guides questioned whether it would ultimately bring any kind of justice to Cambodia. Nuon Chea, at least, has had his day in court – he was convicted of crimes against humanity in 2014 and sentenced to life in prison. It’s clear that the country as a whole is still struggling with this bloody legacy.

Enemies of the People is a small film. Sambath begins by wanting to answer the question of why the killings happened, but he never really gets there. The best he can do is get answers from the men with (literally) blood on their hands (they would have been killed had they not followed orders) and the higher up who equivocates enough that you can see the monster behind his eyes. That it doesn’t find the answer to the big question doesn’t make it any less powerful.