It is a story of how the Seoul, South Korean police were utterly incompetent and let a serial killer go on killing. As for what the officers interviews it sounds like their still in denial that it was their fault. (I can only speak from the English translation). They came off as blaming the system rather then themselves. Even when two officers didn't communicate and the killer walked right out of the interrogation room they spoke as if he planned it all. One redeeming factor was they didn't show his face or give him any type of "fame". Though there was no real focus on the victims either. Overall sloppy as a documentary.
