Criminal Profiling: One Clue Can Identify the Murderer

At night, it was raining heavily, and Zhang Xun knocked on the door of a farmer's house: "Can I stay overnight?" The farmer asked: "How many people?" Zhang Xun took a sharp breath and replied: "Standing in front of you is a sprinter, a marathon runner, a high jumper, a prostitute, a master of sliding door locks, a schemer who planned a kidnapping case, the only designated undercover agent of the police, who has repeatedly solved serious and important cases, a top..." Before he finished speaking, the farmer lowered his hat and closed the door: "There are many people here, everyone." Zhang Xun looked at the small gap on the brim of the farmer's hat and completed the sentence, "The top profiler." Then he turned around and left in the heavy rain, lifted up his black windbreaker, took out his walkie-talkie and said in a low voice: "The serial murderer has been found."