He was buried, but returned alive: how case of serviceman Nazar Daletskyi will affect DNA testing system
Ukraine will review the results of DNA tests of servicemen carried out using a single testing method. The Interior Ministry made the decision after the case of serviceman Nazar Daletskyi, who was declared dead and buried in the Lviv region in 2023, but returned alive from Russian captivity on February 5 this year as part of another prisoner exchange.
The story sparked public outrage, as this testing method is used to identify the bodies of fallen servicemen. It now raises the question of whether it can be trusted. To answer it, a Censor.NET journalist tried to find out how the serviceman was mistakenly declared dead, whether Ukraine has seen similar cases where another person was buried, and what needs to be done to prevent this from happening again.
ONE IN A MILLION, BUT IT HAPPENED
"The day after it became known that citizen Nazar Daletskyi was alive and had returned from captivity, on the minister’s instructions, I and Yevhenii Kolesnyk, Director of the Interior Ministry’s State Research Forensic Science Centre, travelled to Kharkiv, because it was our colleagues in Kharkiv who conducted the testing to generate a DNA profile from the remains that had been found back in 2022, and where a match was recorded with the DNA profile of citizen Daletskyi’s mother," Deputy Interior Minister Leonid Tymchenko told Censor.NET in a comment.
According to Tymchenko, biological materials for extracting the woman's DNA profile were collected in May 2022 after it became known that Nazar could have been captured. However, since this information had not been officially confirmed at that time, he was considered missing under special circumstances. "In such cases, in accordance with the National Police's algorithm of actions, biological material is collected from relatives in order to derive a DNA profile and enter it into the Electronic Register of Human Genome Information, based on the assumption that in such situations, unfortunately, it is possible that bodies will be returned as a result of repatriation or may be delivered directly from the front line. DNA testing of the bodies is also carried out, and then a comparison is made with the data in this register," he said.
According to the deputy minister, Nazar Daletskyi went missing while carrying out a combat mission in eastern Ukraine in May 2022. When the AFU launched the Slobozhanshchyna counteroffensive in the autumn, investigators from various law enforcement agencies had to look into a number of war crimes committed by Russian troops in the liberated areas, including mass killings of civilians. One such case involved the shooting of a convoy of civilian vehicles. The Kharkiv Regional Prosecutor’s Office told Censor.NET that the Investigative Department of the Security Service of Ukraine (SBU) in the Kharkiv region is conducting a pre-trial investigation in criminal proceedings on suspicion of criminal offences under Part 1 of Article 437, Parts 1 and 2 of Article 438, and Part 3 of Article 110 of Ukraine’s Criminal Code. "It was established in the course of the investigation that on 30 September 2022, on the road between the settlement of Kupiansk-Vuzlovyi and the village of Kurylivka in Kupiansk district, in the direction of travel toward the city of Svatove in Luhansk region, a convoy of civilian vehicles shot up by Russian troops was discovered, and there were fatalities as a result of the shelling," the prosecutor’s office said in its response to the outlet. It also said that the remains of unidentified bodies were collected during an inspection of the scene.
According to Leonid Tymchenko, the investigation was conducted within a consolidated criminal case documenting war crimes committed in various districts of the Kharkiv region. He recalled that numerous mass burial sites and torture chambers were discovered in the Kharkiv region at the time. He also explained that the National Police were not directly involved in documenting the shooting of that convoy, but officers were recording and investigating other war crimes, so many of them that law enforcement personnel from different regions of the country had to be brought in. However, forensic examinations of bodies or remains found at the site of the convoy attack were assigned to the Interior Ministry’s Kharkiv Research Forensic Science Centre.
In January 2023, the deputy minister said, one biological sample taken from a shot-up vehicle showed a high statistical probability of kinship with the DNA profile of Nazar Daletskyi’s mother. The Interior Ministry says the match was generated automatically. "There is a specific algorithm that sets out how biological material is handled and how the formula is derived. In this case, the match was 99.99987%," Leonid Tymchenko said. "It is a mathematical formula that produced exactly that percentage of relatedness. This is not a process that depends on an expert’s discretion."
After that, on 13 April 2023, an expert of the Kharkiv Research Forensic Science Centre issued an opinion stating that Ms Daletska could be the mother of the person whose skeletal remains had been examined under an expert report by this centre. At the same time, the expert recommended that an additional examination be ordered, but this recommendation was not followed.
For their part, the centre’s experts say they had not previously encountered such a match between the DNA profiles of unrelated individuals. However, they do not rule out that such a scenario is theoretically possible. "As senior specialists told us, such a match occurs once in a million cases," explained Viktoriia Ionova, head of the Biological Research and Records Department at the Interior Ministry’s Kharkiv Research Forensic Science Centre. "In general, to fully identify a body, at least two DNA methods are currently used. In other words, it is important to establish several relatives or one relative using two methods. At that time, we did not have such an opportunity. We worked with what the investigator provided. But we understood that the investigator was aware of the letter issued by the Electronic Register of Human Genomic Information with its recommendation, so we relied on his discretion."
In addition, another examination was ordered in this case, this time by a prosecutor. We also conducted that examination, established the DNA profile of Nazar’s daughter, and submitted it to the register. However, this time there was no match. The findings were forwarded to the initiator of the examination at his discretion."
At the same time, the Interior Ministry notes that conducting a repeat examination is not a mandatory requirement under current legislation.
The Kharkiv Regional Prosecutor’s Office told Censor.NET that on 12 May 2023, "based on a letter from an investigator of the SBU Investigative Department in Kharkiv region, the skeletal remains were released by Branch No. 2 of the Kharkiv Regional Bureau of Forensic Medical Examination for burial." They were buried with honors at a local cemetery in the village of Velykyi Doroshiv in the Lviv region.
The prosecutor’s office also said that during the pre-trial investigation in October last year, two servicemen of Ukraine’s Armed Forces were questioned as witnesses. They stated that from 2022 to 2024 they had been held in captivity in the temporarily occupied city of Sukhodonsk in Luhansk region together with Daletskyi and, according to them, he had no bodily injuries or wounds.
"In this regard, on 6 December 2025, the prosecutor in the criminal proceedings issued a ruling to conduct an exhumation of the body, the execution of which was entrusted to investigators of the SBU Investigative Department in Kharkiv region."
The prosecutor also asked the expert who had conducted the molecular genetic examination how such a match could have occurred. The expert said that despite a match probability of 99.99987%, a malfunction of reagents could occur and produce a false result," the prosecutor’s office said, adding that after Daletskyi’s return from captivity, he was questioned by an investigator about the circumstances, place, and time of his capture and detention. In addition, with the involvement of a specialist from the Vinnytsia Research Forensic Science Centre, buccal epithelial samples were taken from him, and a forensic examination was conducted.
Furthermore, a letter was sent to the Interior Ministry’s State Research Forensic Science Centre to verify his DNA profile against the Electronic Register of Human Genomic Information in order to establish any kinship matches with relatives. As of now, the prosecutor’s office says no response has been received.
Last week, in execution of the prosecutor’s ruling, the remains buried under the name of Nazar Daletskyi in the Lviv region were exhumed, and steps are being taken to order a repeat forensic molecular genetic examination.
At the same time, the Interior Ministry’s Kharkiv Research Forensic Science Centre denies the possibility of a reagent malfunction, noting that during the examination, a "control DNA" sample is tested in parallel to verify the proper functioning of the equipment and reagents. This, they say, rules out a malfunction.
"We faced a large number of identifications at the start of the war, and the situation remains difficult now. The number of DNA examinations we received in 2023 was twice as high as in 2022. In 2024, it was four times higher," Ihor Davydenko, Director of the Interior Ministry’s Kharkiv Research Forensic Science Centre, told our outlet. "At the same time, the number of experts remained unchanged. Our staff treated and continue to treat their work responsibly. From an organizational standpoint, everything was done properly. All methodological guidelines were followed; we did everything that needed to be done. However, molecular genetic examination does not provide a one-hundred-percent match. What does this mean? It means that such an examination, like any other, is subject to evaluation."
"Moreover, I do not know of any country in the world that in recent years has examined such a number of deceased persons for identification purposes. In any line of work, when you face a heavy workload and large volumes, experience is gained that will later be taken into account in further work."
"In addition, this field itself, molecular genetic identification, is relatively young. It has its own evolution, continues to develop, and corrective measures are introduced."
If we speak about this particular case, on the one hand, it is good news that the person returned from captivity alive. On the other hand, some may question what had been done before. Yet the match was indeed high and was based on an automated mathematical calculation.
Asked a follow-up question about whether there could be a software malfunction, he replied: "When experts receive biological material, they prepare it and load it into the equipment. The equipment produces results, which are then analyzed by experts."
For her part, Viktoriia Ionova added that an expert does not rely solely on mathematical calculations. Before performing them, the expert compares both DNA profiles to assess relatedness at that stage.
"In this case, the expert saw that there were grounds for conducting the mathematical calculations," she said.
– How does the human factor influence the process when an expert evaluates the indicators produced by the system?
– I cannot speak for all experts; I will explain how the work is organized in our department. When we receive DNA profiles from samples taken from relatives of servicemen and from remains, there are several stages in the process of interpreting the results. First, the expert receives the profiles and analyzes them independently; then a senior specialist with greater experience reviews that expert’s work. At the stage of drafting the report, an additional review is conducted.
– So it is ruled out that a single individual could have made a mistake, since all stages are reviewed by other people?
– Yes, multiple times.
AT LEAST TWO METHODS OR TWO RELATIVES
To find out whether similar matches had occurred in the practice of other experts and how such situations could be avoided in the future, we asked Ruslan Abbasov, Deputy Director of the State Research Forensic Science Centre. "A person who returned from captivity alive has, I think, further strengthened the hope of others to see their loved ones alive, even if they may have already lost hope. And that is good. What is bad is that people may lose trust in scientifically grounded methods, one of which is DNA," he said. "And when you ask about a match, it should be treated as a methodological calculation. Probability theory tells us that no event in the world occurs with absolute certainty; there is always a statistical calculation. What is the probability of a match in terms of presumed relatedness? There is relatedness, and there is a direct match.
A calculation is then made based on that 50%, and the resulting probability turned out to be very high. However, when we speak about forensic genetic experts, the public should understand that attention should not be focused solely on percentages. The situation must be assessed comprehensively, how many close relatives were tested and by which methods. The overall picture should be evaluated based on the combination of these factors, especially if other identifiers were absent. In this case, the body was burned and unrecognizable, and it was impossible to identify it by any method other than DNA analysis.
If we speak about forensic support, expert capabilities, technologies, methodologies, and protocols that became available at the beginning of the full-scale invasion, some units had the capacity to conduct testing using several methods, while others did not. However, the number of DNA methods that could be applied when only one relative was available steadily increased. Today, a sample from a close relative can be examined in virtually any laboratory using at least four methods. What does this provide? When we assess a DNA profile comprehensively and visually compare a relative’s sample with an unidentified profile, we can determine whether relatedness exists or not. We then perform mathematical calculations expressed in percentages. The next step should be confirmation or refutation. At that stage, we apply additional methods. It is precisely the combined application and calculation of additional methods using the same sample or another sample from a close relative that makes it possible to avoid such situations today.
To prevent such situations from recurring, we monitor this type of information. Is it possible to safeguard against such cases? There is a solution, and the capabilities exist. Each year, the number of experts increases, methodological approaches improve, and technical capacity is strengthened."
Responding to a question about whether other individuals could have been mistakenly buried, Deputy Interior Minister Leonid Tymchenko said this was the first such case in the Interior Ministry’s forensic institutions. "I can state this with certainty, because we reviewed all information across all our forensic institutions within the system," he explained. "In 2022, we had nine full-profile laboratories. As of today, we have 21 full-profile laboratories and 24 laboratories in total across the territory of Ukraine. And this year, three more laboratories will be added to the Interior Ministry system."
Following what happened in the case of Nazar Daletskyi, conclusions issued by all forensic institutions in cases where testing was conducted using only one method or based on only one relative are being reviewed. We are also considering how to ensure that what was previously a recommendation to conduct an additional examination of a close relative and take its results into account becomes mandatory. This will require amendments to the current regulatory legal acts. Why am I saying this? Because, from a legal standpoint, none of the experts made an error in the case of Nazarii Daletskyi. Likewise, investigators, when they had the examination and conclusion indicating a 99.99987% match, had the right to rely on it and make a decision. From a legal perspective, they were entitled not to act on the experts’ recommendation. Because, as I have already said, it is not mandatory.
It has also been decided that, going forward, examinations in the Interior Ministry’s forensic institutions will be conducted using at least two methods or based on the DNA profiles of two relatives.
In addition, together with colleagues from the Security Service of Ukraine, we will take certain steps to identify to whom the body buried in the Lviv region actually belongs. In this regard, we will also reach out to our international partners."
Tetiana Bodnia, Censor.NET
