Mother Hangul RRMadeo is a 2009 South Korean drama film directed by Bong Joonho, starring Kim Hyeja and Won Bin.
A high school girl is discovered dead on a rooftop in town, shocking the residents and pressuring the incompetent police to find the killer. With only circumstantial evidence placing Dojoon near the scene of the crime, the police are happy with their cursory investigation and arrest the boy. His defense attorney is unreliable, and the police trick Dojoon into signing a confession, leaving him facing a long jail sentence. The police could not figure out why and who would display the girls dead body on the rooftop where the entire town is in plain view.The mother, horrified and unconvinced that Dojoon is even capable of murder, gets involved in unraveling the details of the murder and the background of the victim to try to prove her sons innocence. She scours the town, uncovering salacious details of the girls life, allying with Jintae, who is surprisingly sympathetic towards her plight, and unsettling everyone around her in her determined quest for justice. The mothers investigation and search for the real murderer takes her to an old man at his junkyard. ........
Source: Wikipedia