Criminal investigation is not only a technical subject, but also a social subject. When we focus too much on clues and try to find the truth from these intricate clues, we often overlook the simplicity of the case at the outset.

  Professor Li Yunqing is a superstar in the field of criminal investigation, just like Cruyff in football, he is not only an outstanding practitioner, but also a instructor of rigorous theory. Before the age of 65, he worked as the chief criminologist of the FBI for a long time in the United States. He founded the Forensic Science Laboratory and solved many strange cases. After the age of 65, he returned to Taiwan and devoted himself to writing books and making statements. He also served as the general counselor of criminal investigation, who was appointed by the Ministry of Justice.

  Today, this master investigator appeared in the case analysis class of the police academy and publicly suggested that he should meet a child first. With that, the classroom was in an uproar, and all eyes were focused in one direction.

  The child was listening to music, and his half-opened and half-closed eyes showed that he was very intoxicated at the moment. They didn't even notice the changes in the classroom.

  Song Qiang was very embarrassed, while Li Bowen , the grandson of the old gentleman, had a surprised expression. The long-legged sister stood up and turned around, pulling off the headset that was worn on Gu Tianyou's head. ,

  Gu Tianyou suddenly came to a realization and quickly fell into a daze. Why are you looking at me like that? What was the meaning of Director Song's direct gaze? And who was that old gentleman? Isn't he taking a case study class? What are you all staring at me for? Eh? Why does this old gentleman look so familiar?

  "Are you Gu Tianyou?"

  "Ah, yes, this is Gu Tianyou. Hello, may I ask who you are?"

  Song Qiang couldn't wait to rush up and wake up this punk who didn't know how to bless Gu Tianyou. If the old gentleman was paying so much attention to him, Song Qiang, it was hard to say if he would be overjoyed on the spot. Of course, he could only think about it. First, the old gentleman did not pay attention to him. Second, he did not have the courage to slap him.

  "I'm Li Yunqing ." The old gentleman did not mind introducing himself again.

  Gu Tianyou instantly understood why everyone was paying attention to him. This Taishan Beidou character from the criminal investigation world must have spoken to him just now. As for himself, he was immersed in Lu Ziqi 's matter and didn't respond at all.

  This was a very, very rude thing to do.

  The old gentleman did not mind, nor did Gu Tianyou feel any fear.

  Gu Tianyou stood up and said frankly, "Sorry, my ears were deserting just now."

  Li Yunqing pulled a chair and sat down, casually saying, "What are your ears thinking?"

  Gu Tianyou said, "I'm thinking of a case."

  "You don't have to participate in the next case discussion. Continue thinking about your case. If you don't mind, I want to hear what case you were thinking about after class." Li Yunqing smiled and said, "Let's continue to discuss the case."

  The old professor cleared his throat and said loudly, "Classmates, the reason why I allowed him not to participate in the discussion of this case analysis is because Gu Tianyou made a decisive opinion on the direction of the investigation." He turned around and asked Song Qiang , "Teacher Song, where did the discussion end?"

  "The students are analyzing the case and expressing their opinions," Song Qiang said.

  Li Yunqing nodded and said, "Alright, then I'll talk to you about the investigation of this case and my personal opinions."

  \r \r \r

  Everyone has heard about the case from your Teacher Song, so I won't go into it again. Let's talk about the location of the detection direction I just mentioned. Before we begin, let me tell you a story. After listening to it, you can see what kind of inspiration you can get.

  That was what happened last summer. In the section of the road where the poisoning and murder happened, a Volkswagen car had a flat tire. After breaking through the guardrail, it rolled into a drain on the side of the road. The accident happened early in the morning. There were three people in the car. They were all seriously injured and trapped in the car, unable to save themselves.

  The carriage was crushed and trapped in a family of three as it rolled. The male driver was stuck between the steering wheel and the seat. The six-year-old boy was squeezed in the back seat by the severely deformed carriage. His legs were stuck in the passenger seat, and his blood vessels were ruptured. However, as long as he was rescued and fashionable, it was not life-threatening. The female patient was trapped in the passenger seat below the waist with head injuries and cuts to the arteries of her arms.

  A few minutes later, Cao Xuewen, a road guard, passed by the scene of the accident. When he heard the male driver's cry for help, he squatted in front of the car and discussed the remuneration for the rescue. Then, he found Sun Youcai, a scavenger who was passing by. The two of them tried to flip the car over, but failed.

  About ten minutes later, nearby villagers Gao Zhengzhi and migrant worker Jin Xigui arrived one after another. Together, the four of them had a great chance of flipping the car over and rescuing the injured. In front of their lives, they were supposed to race against time, but they quarreled over a bottle of Sprite that fell out of the car. During the dispute, Gao Zhengzhi took away the Sprite Drink. Jin Xigui thought that Cao Xuewen was hiding something about the remuneration, so she refused to help.

  Twenty minutes later, when Highway 120 arrived, it took another ten minutes to rescue the injured. By this time, the boy had stopped breathing due to hemorrhagic shock. The woman was taken to the hospital and turned into a vegetable. The male driver was not seriously injured and was soon discharged from the hospital.

  Everyone knows what happened next. Gu Tianyou suggested to the task force to change the direction of detection to the highway. The task force gathered information on all accidents reported on highways in half a year and found the names of four victims in the accident narrative records. Thus, it locked onto Liu Zhichao, the suspect and brother-in-law of the silver mine technician. The suspect pleaded guilty to poisoning and murder, and the case was solved.

  The classroom was completely silent.

  A section of the death highway, a traffic accident, a bottle of Sprite drinks, four unrelated people.

  Together, these words constitute the cause and effect of the serial poisoning and murder.

  The students were not only impressed by Gu Tianyou's key tip in this case, but also by the greed and foolishness of the four people and the madness and cruelty of the murderer.

  "When you leave one day, Walking into the crime scene, Remember what I told you today, Criminology can never be summarized by data or experiments. Recognition of human nature is as important as cognitive technology. Technological traces can be forged, but we both have human nature. I've been in this industry for 48 years, and now I only believe in one thing. All evil deeds have roots. The deeper your understanding of human nature, the better it will be for you to judge your motives for returning to crime. "

  "But I remember that you once said in a book that there are traces of all crimes, and that the discovery of traces is fundamental to the punishment of crimes." Gu Tianyou raised his hand and said.

  "That's the United States. All accusations need to be supported by evidence. It's been three and a half years since I returned to China at the age of 65. The situation has changed, and the style of the judiciary is changing. I want to keep pace with the times." Professor Li Yunqing smiled mischievously at Gu Tianyou like an old naughty boy. After saying this, he turned to Song Qiang and said, "Little Song, please lend me your height for a day. I want to talk to this child."

  Song Qiang naturally wouldn't refuse. Before he could say anything, one of the students quit. Li Bowen shouted, "Grandpa, didn't you say you came to visit your relatives? Bring me along too." Li Yunqing glanced at Song Qiang. The latter immediately nodded and said, "Of course, aren't you here to visit your relatives?"

  … … … …

  Ancient Building District Sub-Bureau, Reception Room.

  In front of Li Yunqing and behind Gu Tianyou and Li Bowen , the two young men were stunned the moment they entered the door.

  Ding Baofeng was there, Bai Fenglin was there, and Ma Fuchun, director of the Municipal Bureau, was there. Meng Qingchun, director of the Gulou Branch, didn't even have a seat. Ding Baofeng's lower seat was empty. Li Yunqing walked over and sat down. "He's already here, can we start?" He said. Ding Baofeng said, "It's still Old Dai."

  Dai Xiaolou lowered his head to look at the file. Upon hearing this, he raised his head and glanced at Gu Tianyou and Li Bowen . He nodded and said, "Please introduce the case to everyone first, Comrade Zhao Wanchen of the Ancient Building Branch."

  Zhao Wanchen stood behind Meng Qingchun, dressed in military uniform and full of energy. He took a step forward and saluted the leaders present. Then, he said, "Hello, Commanders, teachers, Commander Dai. Let me introduce the case to you."

  At the beginning of last month, there was a vicious wounding incident on Linhu Street in our district. The police under the jurisdiction of the district quickly attacked after receiving the police report. They captured the suspect Zeng Wenqiang who was preparing to flee on the spot and found 40 kilograms of methamphetamine in the process of searching the murder weapon. After a night-long interrogation by the criminal police, Zeng Wenqiang confessed to the crime of entering the city with the poison of fate. At the same time, he told Yang He that the person he handed over was the head of the Zizui Golden Fan Leisure Zone.

  Forty kilograms of new drugs. This city has never seen such a big drug-related case in its history. No wonder so many big shots from top to bottom pay so much attention to it. Gu Tianyou's heart trembled as he listened to Zhao Wanchen continue to explain the case.

  Subsequently, the criminal police force carried out the orders of Comrade Meng Qingchun, the sub-director, to secretly monitor the Violet Drunken Golden Fans. At the same time, the case was reported to the municipal bureau and the main brigade.

  On the 28th of last month, Comrade Guo Maoxiang, First Grade Police Officer of the Criminal Police Unit of the Municipal Bureau, took the place of Tsang Wen-qiang and went to Violet Drunken Golden Fans to contact Yang He. Afterwards, Comrade Guo Maoxiang disappeared.

  Currently, 72 hours have passed since Guo Maoxiang disappeared. The Violet Drunken Golden Addict is doing as usual. Yang He disappeared from Xingong Street the afternoon before yesterday after asking for leave on the grounds of going home to pick up his clothes. He was walking on the road when he suddenly got into an unlicensed Toyota Hanlanda off-road vehicle that was slowing down, according to Old Fu, who was in charge of monitoring the scene.

  Due to the uncertainty of Guo Maoxiang's life and death, the leaders of the municipal bureau decided not to take compulsory measures against the Zi Zui Golden Addict for the time being, but to conduct an investigation by means of secret investigation. It turned out that there were many problems, but none of them were enough for a criminal case. No trace of Guo Maoxiang was found during the secret investigation. Considering that the meeting place that Comrade Guo Maoxiang and Yang He had agreed to was not the Violet Drunken Golden Addict, there was no direct evidence to prove that the Violet Drunken Golden Addict was related to Guo Maoxiang's disappearance.

  Decoupling means losing control of the suspect, which is considered a low-level mistake in the police world.

  Gu Tianyou realized that it was the same tune again. He exchanged glances with Li Bowen and discovered that this kid's eyes were brighter than when he was on drugs.

  "Is that Team Zhao? I have a question that I want to ask." Hearing this, Gu Tianyou probably understood the reason why he was called here. This case was handled in such a mess that both the manager and the commander had problems. Considering that he might cooperate with these people in handling the case, it was better to say some ugly things first.

  Zhao Wanchen raised his head and looked at Gu Tianyou. He said angrily, "If you have any questions, wait until it's your turn. Right now, your mission is to listen in."

  This son of a bitch treats me like an intern. In front of this daddy, even if the Dai squad is not at the top, how could it be your turn? Gu Tianyou smiled and shrugged. "Actually, I think my mission should be to attend a lecture at the academy." After saying that, he turned around and left with a flick of the door.

  In the corridor, Gu Tianyou hadn't even taken a few steps when Dai Xiaolou 's voice came from behind him telling him to stop. He turned around and saw that even Li Yunqing had chased him out.

  Gu Tianyou thought to himself. He pointed to the office beside him and took the lead in pushing open the door. A First Grade Superintendent was in the middle of his office. Seeing that Gu Tianyou was about to interrogate him when he entered uninvited, he saw Commander Dai, who was carrying the First Grade Inspector Token, follow him. He waved his hand at him and the brother immediately got up and walked out.

  "Old Dai, I won't beat around the bush with you. I probably know what this case requires me to do. Originally, since I chose to do this job, I can't be afraid of taking risks. You know I'm not a coward who fears death, but I can't do this stupid business." As soon as Gu Tianyou entered, he sat down on the table and swayed his legs. He said, "Listen to this case. Cooperating with this level of goods, three heads are not enough for him to sell."

  Dai Xiaolou looked sideways at Professor Li Yunqing and smiled awkwardly. Li Yunqing waved his hand and said, "It doesn't matter. This child is right. Zhao Wanchen is indeed my student, but he is still young and has studied in the United States for a long time. He lacks sufficient knowledge of all aspects of domestic police work."

  Gu Tianyou continued impolitely, "Elder Li is right. I saw that this guy was just a man of words. However, it wasn't all because of him that I caused this ruckus. It was also because of me. The kidnapper gang case just ended a while ago, and I had just rested for three months and was about to put on another set of clothes. I can't accept it anymore in my heart."

  Dai Xiaolou was furious and said with a straight face, "If you have any conditions, just say it directly. Don't beat around the bush with me."

  Gu Tianyou jumped down with a slap and said, "If you know me, then let me be frank. It just so happens that the two parties are here."

  Li Yunqing was slightly surprised, "What's wrong? What else am I doing here?"

  Gu Tianyou nodded and said solemnly, "You must do this." After saying that, he turned to Dai Xiaolou and said, "I request that Elder Li lead the formation of a special task force to restart the investigation into the murder of Lu Zonglin and his wife at home 19 years ago, Secretary-General of the Qinzhou Municipal Party Committee."

  Dai Xiaolou 's face darkened when he heard this. He looked at Li Yunqing and the latter said, "Young man, is this the case that you were thinking about in class just now?"

  Gu Tianyou said, "Elder Li is Elder Li, this is the case. How about it? Are you willing to take over?"

  Dai Xiaolou was afraid that Li Yunqing would agree. He hurriedly said, "Nineteen years have passed since the case was resolved. At that time, Teacher Xu, who was in charge of the case, had already sacrificed more than ten years. Even the scene of the crime has long since changed. Is it meaningful for you to reopen the investigation of this case?"

  Li Yunqing frowned and asked, "Did Xu Tao handle the case?"

  Dai Xiaolou said, "Yes, Director Ding and I were both members of the task force back then. The investigation of that case went on for a long time, and two main suspects were excluded one after another. In the absence of a third suspect, we had no choice but to report the case to the police and hang it up."

  Actually, Gu Tianyou also knew that what he said was reasonable, and he also felt that it was meaningless to reopen the investigation. Moreover, considering the suspect's current identity, the reopening of the case was destined to encounter great resistance. However, he still had to deal with this matter because he called Lu Ziqi 'elder sister '.