Text, photo/ Yangcheng Evening News all-media reporter Fu Yi
Intern reporter Huang Yajing
Correspondents Ou Jingwen, Zhang Yitao, Chen Yumin
"In 30 years of forensic work, I have only two principles, one is to obey the organizational arrangement, and the other is to serve the actual needs of the practice." Recently, Liu Chao, the second-level director of police technology of the Guangzhou Municipal Public Security Bureau, won the 2021 "Nanyue Innovation Award", in an interview with reporters, Liu Chao said that the forensic and research appraisal work he is engaged in has always served the investigation and cracking of cases, evidence trials, and the realization of fairness and justice, which is an inexhaustible source of his innovation motivation. Although many major innovation breakthroughs have been made, Liu Chao has not stopped moving forward, "the form and means of crime have been changing, as evidence appraisal workers, we still have many problems to overcome in the future." ”
Take the lead in establishing research results on DNA identification technology for corrupt specimens and popularize them in other provinces
In the early 1990s, forensic DNA technology was just getting started in China, and it was a blank in the field of forensic applications. By chance, Liu Chao, who was then a graduate student in chemical genetics at Sun Yat-sen Medical University, formed an indissoluble relationship with the public security criminal investigation work.
After graduation, Liu Chao also wanted to study abroad, but he quickly gave up this idea. "Without the party's policy support for poor mountainous areas, I would never have had the opportunity to go to college, let alone have access to these cutting-edge medical knowledge." In order to repay the party's training, Liu Chao joined the guangzhou municipal public security bureau criminal police detachment forensic DNA technology research.
"When I first came, I was alone, and then the talent slowly increased. From choosing a room to buying test tubes and buying equipment, I rode my bike around. Liu Chao recalled that although there were not enough manpower, he had strong support behind him - the first research fund was as high as 880,000 yuan.
In this way, Liu Chao plunged into forensic DNA research. In the past 10 years, in the humid and sweltering climate of South China, he has repeatedly experimented on more than 6,000 foul-smelling and unpleasant decay corpse materials, and finally established dna identification technology for corruption test materials, guiding 18 provinces and cities, including Guangdong, to establish DNA testing laboratories, filling the gaps in related fields in these areas.
For ordinary people, decaying corpses are uncomfortable and even frightening. At first, Liu Chao was the same, but he quickly overcame the psychological obstacles. Because, in the eyes of the forensic doctor, the corpse is evidence of materialization, the forensic doctor's responsibility is to speak for the deceased. "It reminds us to fear life."
Sometimes at the scene, the body was highly decomposed. Returning from this scene, Liu Chao's clothes and hair were full of the smell of decaying corpses. "I can't go away for three or four days." Due to years of exposure to radioactive isotopes, rotten gases and other harmful physical evidence, Liu Chao's hair fell off one by one, and his white blood cells seriously declined, and he fell ill in front of the workbench several times.
DNA technology is magical in the "reunion" operation and the murder attack
Through in-depth research, Liu Chao obtained key information on forensic science applications such as heterozygosity and individual recognition, which provided theoretical support for individual identification, parental identification and DNA database construction for DNA testing.
In 2000, the Physical Evidence Appraisal Center of the Ministry of Public Security, the Public Security Department of Liaoning Province, the Beijing Municipal Public Security Bureau, and the Guangzhou Municipal Public Security Bureau jointly established the world's first "anti-abduction" DNA database. It is the large-scale application of this key DNA technology that has helped reunite many separated families.
There was once a couple from Maoming whose children were abducted while working in Dongguan. In order to find their children, they traveled south and north to more than 20 provinces and cities across the country, traveling more than 80,000 kilometers. Liu Chao helped them find the child in Guizhou through DNA comparison. "On the day of the confession, before dawn, they got up and went to the ground to dig up peanuts and send them to us, and then sent us pennants." Liu Chao said, "This scene, I will never forget. ”
The tears of joy and tears when the relatives were reunited made Liu Chao feel that all the hard work was worth it. The use of DNA technology to solve difficult murders is the moment when Liu Chao's sense of achievement is the greatest.
Over the years, What impressed Liu Chao was the 2004 case of a major murder in Huangpu, Guangzhou. In the rental house late at night, the lady of the hair salon and two young women in their twenties were killed, and another woman was seriously injured, and the murderer had escaped. Focusing on the clues left at the scene, the police handling the case conducted a large number of visits and investigations. However, due to the technical conditions at the time, the police were unable to find the whereabouts of the murderer.
In 2020, in the backlog of homicide cases deployed by the Ministry of Public Security, the Guangzhou Municipal Public Security Bureau set up a special technical team to use the latest technology to attack the case again. This time, DNA technology highlights the "divine power."
The police handling the case re-sorted out the relevant information before and after the incident, and Xue Mou, a man in Hancheng City, Shaanxi Province, entered the police's sight.
After the police investigation, they learned that more than ten years ago, Xue had come to Huangpu, Guangzhou, and then returned to Hancheng for some reason and had not gone out again, and usually did not take planes, trains, buses, and rarely went out. "In fact, after committing the crime, this suspect fled back to Shaanxi on the same day, worked in the 'black coal kiln', and worked for more than half a year and really couldn't stand it, so he returned to the village." Liu Chao said that Xue Mou knew that he was carrying people's lives, and he had been very honest for more than ten years, and he did not dare to chase after others who borrowed money and did not pay them back.
Xue Mou is so low-key, how can the police lock him? Liu Chao said, "It depends on DNA technology." On October 23, 2020, the DNA information comparison test results were released, and Xue Mou was the real murderer of the murder.
At the moment when the real murderer was caught, Liu Chao thought to himself that the wish of generation after generation of Guangzhou criminal police had finally come true.
Despite the honors, he has never stopped innovating
Over the past 30 years, around DNA technology, Liu Chao has made breakthrough achievements in cause of death identification, DNA database technology, DNA testing of difficult specimens, research and development of domestic reagents and equipment, and made outstanding contributions to maintaining social stability.
After 10 years, Liu Chao led the team to make major breakthroughs in key technologies such as diatom enrichment extraction, qualitative quantification, DNA testing, etc., and the results reached the international leading level, which has been promoted and applied in 29 provinces and cities across the country, and the technology has been identified for more than 3100 cases.
Under the situation that DNA testing reagents and equipment are subject to foreign countries, Liu Chao's team has developed high-resolution reagents such as Y-DNA, and the efficiency and price are significantly better than similar foreign products. The price of reagents is less than 50% of similar foreign products. The reagent has been routinely used in more than 630 laboratories across the country, and more than 300 homicide cases have been detected in Guangdong alone in recent years.
These technological innovations have added liu chao's honor. He has won 4 second prizes of national scientific and technological progress, of which 3 ranked first; formulated 6 public security industry standards, and obtained 10 authorized invention patents; won 2 first-class personal merits, and won the honors of second-class heroic model of the national public security system, national May Day labor medal, national advanced worker, national outstanding scientific and technological worker, and outstanding communist party member of Guangdong Province.
Liu Chao said, "In the future, we will develop in the direction of more accurate, more trace and more complex DNA technology. (For more news, please pay attention to Yangcheng Pie pai.ycwb.com)
Source | Yangcheng Evening News Yangcheng Pie
Editor-in-charge | Chen Qian