here was never any doubt that Xia Junfeng was a killer: Four years ago, in a flash of panic and fear, he stabbed to death two urban enforcement officials who had sought to punish him for operating an unlicensed shish kebab stall. On Wednesday morning, Mr. Xia, a laid-off factory worker and father of a 13-year-old boy, was put to death in the northeastern Chinese province of Liaoning