The journey of zoning the grave trench from documentary photos
The clue originated from documents about the Chi Hoa - Cho Quan cemetery, now Le Thi Rieng Park, provided by architect Nguyen Xuan Thang. Through comparison of historical photos, satellite photos, military maps and archival documents, functional agencies initially determined that on February 12, 1968, the old Saigon government collectively buried many liberation soldiers and patriotic compatriots in at least 3 large grave ditches. After nearly 6 decades, the terrain completely changed, making it difficult to determine the location.
To verify, architect Nguyen Xuan Thang's team analyzed satellite photos, air photos of the French army taken in 1951, maps of Saigon through many periods, military reports and dossiers on clearing Do Thanh cemetery.
Using the method of converting the reference system, stacking non-images and satellite images, the group cordoned off 3 areas suspected of having mass graves, about 500-1,200m2 wide, near the fishing pond behind the Traditional House Park. This location coincided when compared with the water tower in the Sanctuary and Nguyen Gian Thanh street campus.
The research results were transferred to the National Steering Committee for Searching, Repatriating and Identifying Martyrs' Remains (National Steering Committee 515). On that basis, the Ministry of National Defense, Military Region 7 and Steering Committee 515 of Ho Chi Minh City directed forces to review documents, meet witnesses and conduct field surveys. On May 31, 2026, the first survey delegation of the Ho Chi Minh City Command was present at the park. Officers and soldiers persistently met with each witness, recorded audio, made diagrams and compared them on digital maps.
By June 15, 2026, the Ho Chi Minh City Command coordinated with the Design Institute under the General Department of Logistics and Technology, Hanoi University of Science and Technology, University of Science and Ben Thanh Water Supply Joint Stock Company to use ground-penetrating radar to survey in three areas. After four days of independent work, all four units identified two areas with unusual signals underground. On June 23, 2026, the first hoes were performed at point A. After two days of peeling off the soil layer, the search force discovered the structure of the collective burial trench, hammock slabs and the first sets of remains.
Immediately after that, the Ho Chi Minh City Command advised the Steering Committee 515 of Ho Chi Minh City and Military Region 7 to fully prepare conditions for the gathering phase, establish a temporary command headquarters, DNA sampling area, gift house, and at the same time mobilize Teams K70, K71, K72, K73 and specialized teams to ensure that the gathering process takes place in accordance with procedures, solemnly and safely.
The journey of decoding DNA to find identity
Along with the remains, the search force has collected many artifacts such as magazines, bullets, combs, mobilization decisions, rings, pens and medicated oil bottles. Among them, an artifact carrying information about martyr Huynh Van Quen has opened up an important clue to verify relatives. All remains and artifacts are recorded, data digitized and biological samples taken to serve DNA comparison work.
Doctor Vuong Gia Bao - examiner at the Ho Chi Minh City Forensic Center - said that DNA extraction from teeth and bones is very complicated. The calcium layer protects DNA but also causes difficulties in processing; long-term bone samples are easily contaminated with impurities, which can disrupt the analysis process if not cleaned thoroughly.
After nearly 60 years, most of the nuclear DNA has broken down and decomposed. Therefore, experts have switched to decoding mitochondrial DNA, a type of DNA with a larger number and higher durability, helping to increase the ability to create identity profiles from long-standing remains.
The mitochondrial DNA is only inherited from the mother line, so the comparison sample must be taken from relatives on the martyr's maternal side such as mother, grandmother, siblings of the same mother or children of sisters. The biological sample is processed, extracted, replicated DNA and analyzed to create a genetic profile. If the sample is severely damaged, the examiner must perform it many times until the sample is gone.
In recent days, the working pace of the sample taking team has always been maintained in a hurry from early morning to late afternoon. For each member, this is not simply a dry forensic procedure, but an order from the heart, a deep gratitude from the young generation to those who fell for national independence. All share a high determination: Devoting all their strength and meticulousness in every smallest operation to keep every opportunity to identify identities, with the greatest desire to soon bring them back to their homeland and family.
