in this emotional and gripping movie rithy panh confronts former killer and the few survivor ( among the thousand of inmate ) of the slaughtering in the horrible s 21 prison in phnom penh during the red khmer regime in kampuchea . the guard show the place be people be club to death and not shot . the sound of gun shot would have create panic among the group of prisoner wait to be kill . the inmate confess blatantly that under untenable torture they tell their interrogator everything those want to hear and denounce a traitor even the most innocent of their compatriot . the movie create a nearly unbearable emotional climate by show the extreme excess of a marxist ideology go mad and kill even intentionally child and baby . a one party state be instal where the top force a terror regime on the entire population . this movie be a must see for all those interested in the history and the nature of mankind .