Gap Dong (2014)

Ha Mu Yeon's father killed himself after becoming a suspect in the case of the Iltan killer, also known as Gap Dong. After the statue of limitations is up on the case, the original detective returns to continue his investigation. However, Moo-Yeom is now a detective and works to capture Gap Dong as well, refusing to believe that Gap Dong is dead. New evidence for Gap Dong appears in front of Moo-Yeom and he sets out to catch him once and for all.