Rainbow Eyes

Rainbow Eyes Hangul RRGamyeon is a 2007 South Korean crime thriller film directed by Yang Yunho. The story follows a police inspector who discovers that his friend is now a serial killer.

Shortly after the first grisly murder a second murder occurs. The victims seem to be unrelated but the modus operandi seems the same. When the police delve deeper into the victims background they discover that the two victims were stationed at the same military base many years ago. A month prior to their discharge they were transferred to another base along with a third man by the name Jong Ha. The police now believe Jong Ha could be the next victim or the killer. But their investigation has only led them to Kyungyoons old friend, Yoonsuh, which makes the case more confusing.

Source: Wikipedia