South Korean police on Monday are investigating a man in his 50s on suspicion of killing his upstairs neighbor for making what he claimed was excessive noise, marking the latest incident in which inter-floor noise has led to a violent crime. The suspect is accused of attacking the woman in her 30s at around 4:40 p.m. Sunday in the staircase of their residential building in Sacheon, South Gyeongsang Province, after an...