设下圈套 — “To set a trap or a snare to trick or deceive someone”

Once upon a time, in Shouchun County, there lived a magistrate named Li Chong, who was renowned for his extraordinary ability to solve cases. He often set up traps for the parties involved to fall into, thereby revealing the truth of the cases. For instance, he would have someone inform the parties that their child had died and observe their reactions, thus reuniting lost children with their parents. Disguising himself to identify fugitives was another excellent example of his methods.