Liu Chao, the second-level police technology director and forensic expert of the Criminal Police Detachment of Guangzhou Public Security Bureau, used DNA to decipher a large number of secret codes of difficult and murder cases over the past 30 years – Text/Yangcheng Evening News All-Media Reporter Dong Liu
Photo/Addressed by the interviewee
“I just started doing this job, dealing with various corrupt corpses, and I couldn’t eat, I felt uncomfortable and had nightmares. Later, when I got used to it, I saw the corpse, and I felt that it was the ‘soul messenger’ talking to us…” Liu Chao, who participated in the fight against the new round of local epidemic in Guangzhou and was in a quarantine hotel, revealed his thoughts for 30 years as a police officer in an interview with a reporter from Yangcheng Evening News.
As the second-level police technical director of the Criminal Police Detachment of Guangzhou Public Security Bureau, 58-year-old Liu Chaogang was awarded the title of “Outstanding Communist Party Member of Guangdong Province”. In addition, he has many identity cards: professors and doctoral supervisors, deputy head of the Forensic Genetics Group of China Criminal Technology Standardization, deputy director of the Physical Evidence Professional Committee of the Chinese Forensic Society, deputy head of the expert group, and director of the Academic Committee of the Key Laboratory of the Ministry of Public Security of Forensic Pathology.
After retiring from his leadership position last year, Liu Chao focused on solving the accumulated murder cases. In the past year, he has solved seven unsolved difficult cases that have not been solved for many years, and DNA is still his powerful weapon for “attack”.
After resigning from leadership position, Babaylan is mainly devoted to solving murder cases
Yangcheng Evening News: After resigning from leadership position last year, can you breathe a sigh of relief?
Liu Chao: Although he no longer served as the captain of the Criminal Police Detachment of the Guangzhou Public Security Bureau last year, some murders that have been “accumulated” in Guangzhou in the past 20 or 30 years have not been solved, and it has always been a big stone that has been weighing on my heart.
My previous detachment captains always told me before retirement: Which case has not been solved? I hope you will solve it before retirement, and I hope you will transfer the unsolved murder case to the next one.
The criminal investigator has a special feeling – solving the case. The most important thing in solving a case is to solve a murder case. The most difficult thing in a murder case is the accumulated case, which most tests the feelings and abilities of the criminal investigator. So, after I stepped down from my leadership position last year, I spent more than a year spending my main energy on solving murder cases.
Yangcheng Evening News: What are the characteristics of these murder cases? Liu Chao: Some cases were encountered when I was in my twenties and thirties when I first joined the public security work. The case site – the blood flowed like a river on the ground and the corpse was high and the body was defeated. There was no technical condition to solve the case at that time. Although so many years have passed, theseThe scene of the case is still vivid in my mind.
Yangcheng Evening News: Why are these cases difficult to solve? Is it because there is little physical evidence?
Liu Chao: The difficulties we are talking about in criminal cases are not only reflected in the fact that there is not much evidence on the scene. The causal relationship of the case is unknown, the motive for the crime is unknown, and the nature of the case is unknown – such cases are difficult to solve.
For example, if a person who is usually very good and honest suddenly goes to another place to kill someone he doesn’t know, and there is very little evidence on the scene, it is difficult to solve such a case.
Like the case of “2004·7·13” in Huangpu, Guangzhou, BabaylanThe suspect sold apples with his father in Huangpu when he was a child. Before committing the crime, he wanted to do business, but he didn’t have enough money. He came to Guangzhou and went around and went to a hair salon shop. The hair salon shop asked him if he wanted to stay—twenty or thirty yuan. His motive at the beginning did not want to kill people, but during the prostitution process, he used local materials to commit murder due to problems such as prostitution. He killed one person first, but this process alarmed the other person… The man killed someone the night he came to Guangzhou and left Guangzhou the next day after the murder. After returning to Shaanxi, he hid in the coal mine for more than six months. Later, he felt that the wind was calm and returned to the village and never left the village again. He endures others bully him; he dare not ask for money or chase after others owe him money. Everyone in the village said that he was an honest and good person, and he lived like this for more than ten years after the crime.
Yangcheng Evening News: How did that break through?
Liu Chao: Rely on DNA. There was a small episode before we arrested people. The household registration information showed that he was only 1.5 meters tall, but we analyzed based on the crime scene that the suspect should be 1.7 meters tall. In this case, do you dare to arrest someone? I made the decision and it is absolutely fine to catch it, because we have the strong technical support of DNA. Later I found out that the “gap” of about 20 cm is that the height data on the household registration materials in the early years was self-reported Babaylan, which is inaccurate. Thanks to technological innovation and progress, such a backlog can be broken.
Yangcheng Evening News: BabaylanWhat did he react when you arrest him?
Liu Chao: When we found him, he cried, and the first thing he said was “Finally freed.”Cinema.
So back to what I said just now, this case is difficult to solve. The difficulty lies in the fact that he came to Guangzhou by chance, left after committing the case, and never committed the crime again after returning. He has been an honest man for more than ten years, got married, and has a son and a daughter. But even so, he Komiks could not escape the judgment of his conscience, saying that he often had nightmares at night. After being arrested, he told us that he wanted to see his wife and said, “Wife, sometimes I lose my temper because my heart is not calm (pure), I hope you forgive me.” Later, I accompanied him to Guangzhou by train. He cooperated very well along the way, telling us the whole case and the journey of his thoughts over the years.
Liu Chao investigated carefully at the scene of the case and did not let go of clues.
The criminal investigator was more excited than anything else when he found clues of major cases
Yangcheng laterBabaylan Report: After retreating, how many such murder cases have you solved?
Liu Chao: Our criminal police detachment and I solved the murder case brigade, and last year we solved a total of 92 murder cases. I used to be the “top leader” of the criminal police detachment and didn’t solve so many cases. Why? It’s because I’m now calming down and being able to concentrate on solving these accumulated cases. There are 7 cases where I led the team to find clues and arrest people. These seven cases were unsolved cases that have been unsolved by previous task forces over the years. In addition to correct ideas and scientific methods to solve these cases, it also requires hard work. For example, the case I just mentioned about going to Shaanxi to arrest people, we found clues through reanalysis of the case materials for more than half a year. We went on a business trip for a week and used DNA technology to survey clues. I took the lead in forming a DNA expert group from Shaanxi, Shanxi and Guangdong provinces to analyze it. Every night, I had to get up before 5 a.m. to start my new day’s work.
Although it is hard, others cannot understand the excitement after solving the case. Why do I keep talking about these cases? Because it’s very excited.
Yangcheng Evening News: What is the key to solving these old murders?
Liu Chao: DNA! I’m a DNA person.
For example, in March this year, I led a team to Tiantang Town, Yunfu City to arrest the suspect in a murder case. This case was a double murder case in March 2007 in Panyu, Guangzhou. I remember when I was at the scene of the crime, the entire ground was covered with blood, and my feet could not stop trampling on blood. This case has not been solved for many years.
Last year we sent police forces to investigate and judged that it was an acquaintance who committed the crime, but the suspect was not found. I led the team to stay in Yunfu Paradise Town for more than a week, and finally identified two suspects. They had to be good since childhood. After coming to Guangzhou, they heard that the couple had money at home, so they knocked on the door and robbed and killed people, and each person killed one. After the killing, they formed an offensive and defensive alliance – no matter who said it, the other person could not escape. At that time, among the many blood stains at the crime scene, we only found trace blood marks of the suspect. But we have not given up for so many years, and finally we have to find the perpetrator by searching the DNA genealogy.
At nine o’clock the night before the arrest, I drove to Yangchun. It was already eleven half past the evening, and the on-site meeting was about to be held. One of the suspects was caught at about 2:30 in the morning the next day, and Komiks was a preliminary trial overnight. At around six o’clock the next morning, we went to the construction site to arrest the second suspect, but we didn’t close our eyes all night.
Yangcheng Evening News: I often work like this. Do I don’t want to do it because I feel tired?
Liu Chao: When we criminal investigators discover clues to major cases, they are more excited than anything else and absolutely have no feeling of being tired, so I often say that we will never say we are tired. When we solve the difficult murder case, we feel the greatest sense of accomplishment. This is to give the deceased an explanation, and it can also create a deterrent to the criminal: as long as the case is done, justice will come sooner or later.
The most difficult case: There are only one case in the Panyu family annihilation case, including the suspect DNA
Yangcheng Evening News: In your career, which case is the most difficult case for you?
Liu Chao: The 2014 Guangzhou Panyu Family Impact Case – Three Generations of Six Life. I remember it very clearly. It was April 29, and I arrived at the scene and stayed there for six days. This case was the most difficult case I have ever experienced. When I mentioned this case, I replayed the scene at that time like a movie –
How was this case discovered? At that time, the neighbor downstairs found that water was always dripping on the roof, so he went up and knocked on the door.No one responded for a long time. After the community security guard came, he found that the family had not reported for decoration and the owner’s phone number could not be reached. Finally, he called the owner’s relative to open the door. As soon as the door opened, the body was found, so the case was reported.
When I arrived at the scene, there was still water in the house. The criminal stayed in the house for more than 20 hours. The criminal first Babaylan checked the site in the community, then bought ropes, searched online for how to avoid surveillance and not be noticed, and bought a new set of clothes before committing the crime. Then he went up to the roof, tied the rope to the roof, and slipped through the window to the resident’s house downstairs to commit the robbery. After the first person in the house discovered him, he killed the other party. This process alarmed the others in the house, and he was so angry that he was so angry… The criminal was very cruel. A female victim had already run out of the door, but was dragged into the house and killed by him.
After the murderer, the criminal cleaned the scene in the house and wiped the evidence, mopped it with a mop, rinsed it with water, and burned it with fire. He also washed away all the blood from the body and left.
After we checked the scene, the question arises: six people were killed at the same time, was it one person or how many people committed the crime? Difficulty in identification! Is the family extermination due to revenge, robbery or other reasons? Qualitative difficulty! I conducted continuous inspections of the site from April 29 to May 5. During this period, the Ministry of Public Security was preparing to send a team of experts to Guangzhou to guide the case solving on May 3. We reported that we were confident that we would handle the case, so the Ministry of Public Security decided to give us two more days. The task force is under great pressure day and night.
On May 6, among thousands of samples, the DNA of the suspect was finally found in one! After obtaining this major breakthrough, our deputy director in charge of criminal investigation led a team to arrest people, and the suspect was arrested in more than ten minutes.
How cunning is this suspect? He grabbed the U-shield and bank card from Cinema, got the password Komiks and did not withdraw money for the time being, but planned to wait until the police put the case down and relaxed their vigilance before withdrawing the money. He took off his computer host, hid the card in the computer, and installed the host case.
Yangcheng Evening News: Did the suspect who committed the crime think that you could find him?
Liu Chao: He didn’t expect it, he never dreamed it, let alone so quickly. He felt that his plan was a “hundred secret” – new clothes, new ropes, and new shoes, new hair styles, changing postures when walking to avoid monitoring. In order to avoid investigation, he carefully designed all of this.
Seeing the corpse now is like seeing the “soul messenger”
Yangcheng Evening News: Forensic ThisThe profession is quite special, and he often deals with corpses or even highly corrupt corpses. Many people dare not even look at such evidence photos in court. Do you feel discomfort or fear in your heart in this profession?
Liu Chao: I just started doing this job and dealing with various corrupt corpses. I can’t eat, I feel uncomfortable and have nightmares. Later, when I get used to it, when I see the corpse, I feel that it is the “soul messenger” who is talking to us, and the soul of the deceased is giving you the task of finding the truth. We ate the boxed lunch on site and continued to do it after dinner.
Many people feel uncomfortable when they see the corpse. Our forensic doctor objects the corpse. Seeing the corpse is like a car lover seeing the best car. Over time, when we look at the corpse, we will no longer feel uncomfortable and other things. On the contrary, finding the truth is our job. You have this kind of responsibility. The more difficult the case is, the more you test your ability, technology and resilience.
Sometimes, when I go to a scene, I step on it and stumble on the maggots. After I come back, there are maggots in the soles of my shoes, and my clothes smell like corpses for two or three days. Therefore, if we have been to such a site, we usually go back to our unit to wash and replace our clothes, and sleep for two days before going home.
Yangcheng Evening News: How long does it usually take for a person who works for forensics to go from discomfort to adapting?
Liu Chao: A forensic doctor who loves this profession can overcome the various discomforts caused by seeing the corpse within about three years, but some people who study forensics cannot do it in the end, and some even faint and cannot do this job.
Yangcheng Evening News: I have been doing this job for 30 years. Your understanding of justice and life should be different from that of ordinary people, right?
Liu Chao: Let me tell you, sometimes, we go to search for the corpses. When the corpses are dug out and see the light of day again, it suddenly rains heavily on the scene. I have encountered such a situation four or five times, and from this I feel that the way of heaven is bright and the net of law is vast. This also seems to be a reminder of the world: everyone must have a sense of awe for life.
People introduction
Liu Chao: Focus on DNA solving cases and fills the gaps with multiple achievements
Liu Chao is the main founder of forensic genetics in my country. In the early 1990s, forensic DNA technology was blank in many ways. He conducted repeated experiments on more than 6,000 foul-smelling corrupt body examination materials. After 10 years, he established DNA identification technology for corrupt body examination materials, guided the establishment of 18 provincial and municipal DNA laboratories, filling the gaps in these regions; built my country’s “ministerial-provincial-city” DNA database to realize data sharing and large-scale application, and Guangdong Province alone directly compared more than 300,000 cases. Komiks
Cause of death of rotten corpses in the waterKomiks is a major problem recognized by international forensic science for a century. After 10 years, he led his team to make major breakthroughs in key technologies such as diatom enrichment extraction, qualitative quantification, and DNA testing. The results reached the international leading level and made identifications for more than 3,100 cases. In response to the issue of the reliance on import of key reagents for DNA testing, he took the lead in developing 12 series of reagents such as high-throughput Y-STR, which forced similar foreign products to reduce the price by more than 50%. This result has been promoted nationwide, and Guangdong alone has solved more than 300 murder cases in recent years.
He formulated 6 national industry standards and was authorized 10 invention patents; 12 research results reached the international advanced level, and won 4 second prizes of national scientific and technological progress (three of which ranked first); he won 2 first-class individual merits, and won the National Advanced Worker, National May 1st Labor Medal, National Outstanding Science and Technology Worker, National Outstanding People’s Police and other honors.