Police have arrested a 62-year-old man who allegedly killed six people in a gun rampage across Shanghai late Saturday, state media reported. The shooting spree left four workers at a chemical factory, a taxi driver and a sentry at a military barracks dead before the perpetrator was arrested, Xinhua news agency reported Sunday. The killings were triggered by an “economic dispute” with one of the man’s colleagues at the chemical factory at about 5 pm (0900 GMT) on Saturday, the Shanghai-based Xinmin Evening News website reported. The suspect, identified only by his last name Fan, allegedly beat his colleague to...