He is a DNA testing technology expert, leading the team to break through technical problems; he is a forensic doctor who runs to the front line of criminal investigation and overcomes one difficult and unsolved case after another; he also participates in the establishment of a "kidnapping" DNA database, helping countless family reunions. He is Liu Chao, director of the Guangzhou Institute of Forensic Science and Technology.
A few days ago, Nandu and N video reporters interviewed Liu Chao. Talking about the feelings of focusing on police technology innovation over the years, he said: "The most important points are three points, obey the arrangement, target the industry problems; be willing to be lonely, persevere; and finally have team spirit. ”
Established the Guangzhou Public Security DNA Laboratory
"After graduating from college, I stayed on to teach and worked as a teaching assistant for three years. The graduate student was admitted to Sun Yat-sen Medical University, and the purpose of studying medicine was originally to become a doctor. Unexpectedly, during his graduate studies, Liu Chao accidentally became acquainted with public security criminal investigation work because he helped solve a murder case.
In the early 1990s, forensic DNA technology was just getting started in China, and there were still many gaps in the field of forensic applications. In the investigation of a case, public security investigators were difficult to identify the gender of a fragment of a corpse. In the end, Liu Chao, who participated in dna technology research during his graduate studies, used his professional knowledge to determine the gender of the victim and break through the bottleneck of case investigation.
On the occasion of graduation, Liu Chao was assigned to the Guangzhou Municipal Public Security Bureau to plan to carry out DNA testing, "When I first came, I was the only one, and then two people were added, and we went from riding a bicycle to buying test tubes, selecting experimental consumables, to decorating the laboratory, and doing everything by ourselves." ”
In 1991, in an 8-square-meter room, Liu Chao and his colleagues began construction of a DNA laboratory. He recalled that although he started from scratch, the Guangzhou Municipal Public Security Bureau gave sufficient protection, and the first research fund was 880,000 yuan, "which was a very large amount at that time." ”
In the first 10 years, Liu Chao and his colleagues overcame the technical problems of DNA testing of old and corrupt specimens, established a DNA gender and STR testing technology system for obsolete corruption specimens, and guided 18 provinces and cities, including Guangdong, to establish DNA testing laboratories.
Nandu reporter learned that Liu Chao's technical team took the lead in establishing digital STR typing technology, laying the foundation for the localization of DNA reagents; the sensitivity of the technical system has been greatly improved, and the inspection time has been shortened from 1 month to 1 day, making a breakthrough in the DNA testing of obsolete, corrupt and trace samples. The main research achievements of the project won the second prize of the National Science and Technology Progress Award in 2002.
Participated in the establishment of a database of "anti-abduction" DNA
In 2000, the first "anti-abduction" DNA database in the world was jointly established by 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.
"At that time, it was called building, using, and summarizing, and I wanted to use DNA technology to make scientific determinations." Liu Chao told Nandu reporters that the establishment of the DNA database of "anti-abduction" was also from scratch, and the 4 laboratories exchanged while doing it. In the 2000 "anti-abduction" special struggle, the DNA testing laboratory of the Guangzhou Municipal Public Security Bureau completed 13,038 sample tests and recovered 119 children, and the family reunions in many "abduction" cases have made him unforgettable.
He recalled that in that year, the children of a Maoming couple were abducted, and the two went south and north, looking for many provinces and cities across the country, but there was no news. Eventually, guangzhou police used DNA technology to help him retrieve the child. After hearing the news, the couple immediately set off from Maoming to Guangzhou, carrying a pennant given to the police. Looking back on the scene of that year, Liu Chao still said: "This is unforgettable for me. ”
In the process of continuous development and upgrading of DNA testing technology, the story of reunion has also been staged. In May 2021, on Mother's Day, Humen Town, Dongguan City, held a recognition ceremony. Ms. Liu, who had been abducted for 32 years, finally met her biological parents with the help of the police. At the scene, Liu Chao read the conclusion of the mother's and daughter's DNA identification and witnessed the scene of the reunion. The whole village set off firecrackers to celebrate and set up a feast to bless.
Liu Chao told Nandu reporters that since 2000, the effectiveness of "cracking down on abduction" has been continuously enhanced, and one of the keys is the continuous progress of DNA testing technology. At the same time, he called on the public to dare to report or ask for help from local public security organs for children of unknown origin. Relatives of abducted and missing persons should also know that the police have provided them with free access to DNA collection and testing.
Build a talent team for sustainable development
"In the case of humidity and high temperature, some corpses are beyond recognition in two or three days, and the problem of cause of death is solved, and other problems are solved." Liu Chao introduced to the Nandu reporter that in view of the development of the southern water system, the identification of the cause of death of corpses in the water is also another major problem.
In this regard, over the years, Liu Chao led the team to establish an artificial intelligence-based automatic search and comparison technology for diatoms, the efficiency has been significantly improved; the establishment of a drowning algae DNA detection technology system, significantly improving the accuracy and evidentiary power of drowning diagnosis, the results have been listed by the Ministry of Public Security as a key promotion project, has been promoted and applied in 29 provinces and cities across the country, the application of this technology to identify more than 3100 major difficult cases, for the characterization and disposal of case events played a key role, the main achievement won the second prize of the 2017 National Science and Technology Progress Award.
In addition, the high-resolution reagents such as Y-DNA developed by Liu Chao's technical team are significantly better than similar foreign products. The price of reagents is less than 50% of similar foreign products. Listed as a national key criminal technology promotion project, it has been routinely applied in more than 630 laboratories across the country and has played a key role in solving the long-unsolved backlog of murder cases. The achievement won the first prize of Guangdong Provincial Science and Technology Progress Award in 2020.
On November 1, 2021, the Guangdong Provincial Party Committee Talent Work Conference commended the winners of the 2021 "Nanyue Outstanding Contribution and Innovation Award", and Liu Chao won the 2021 "Nanyue Innovation Award".
"I'm a forensic scientist. From 1991 to the present, from the police for more than 30 years, I feel very honored to receive this honor, and even after hearing the news, I feel a little surprised. Liu Chao sighed.
In the past 30 years, Liu Chao has been engaged in forensic science research and identification, and has made breakthrough achievements in cause-of-death identification, DNA database technology, DNA testing of difficult specimens, and research and development of domestic reagents and equipment. He has won 4 second prizes of the National Science and Technology Progress Award, of which 3 ranked first; more than 6,000 major and difficult cases were inspected and inspected without a single error.
Today, more than 100 people in the Guangzhou public security team are engaged in forensic DNA technology research and identification. Liu Chao sighed: "From 'post-75' to 'post-85' to the current 'post-95', we have established a sustainable talent team and strive to make new breakthroughs in some common technologies and key technologies. ”
Producer: Nandu Instant
Written by: Nandu reporter Ao Yinxue