Who are they? A retrospective study of unidentified bodies in Institute of Medical-Legal Paris from 2018 to 2023.

"I still don't realize that he's dead.... I cried over it. It makes me sad to know that he was buried unaccompanied on his last trip. We were all shocked." This testimony corresponds to a family whose relative was buried in an anonymous grave 6 months after his disappearance was reported to the police. It is estimated that between 1 000 and 3 000 unidentified bodies are buried in anonymous graves in France each year. Most of these decedents have passed through the medico-legal system. However the identification of these bodies, outside the context of mass disasters, remains a complex problem. Several national and international publications have highlighted the prevalent problem of unidentified burials and the consequences for families who do not know the fate of their loved ones, specifically, whether they are alive or deceased. This 6-year retrospective study (2018-2023), covering a total of 2 324 unidentified decedents admitted to the Institute of Medical-Legal Paris (IMLP), aimed to assess the impact of the identification protocol implemented in 2017 on the number of bodies that remain unidentified (n = 164). In addition, this study aimed to establish profiles for individuals who remained unidentified with the objective of identifying the factors that hinder their identification and developing correlated methods to address these issues. The results of this study were compared with other published studies to highlight the global problem and the ongoing need for collaboration between forensic practitioners and relevant authorities.

Key points: Despite great advances in human identification, unidentified decedents remain a global problem.This 6-year overview study covering a total of 2 324 unidentified bodies admitted to the IMLP provided relevant information about the unidentified decedent population and assessed the impact of a protocol established in 2017 on the rate of deceased buried without identity in Paris.The need to establish a national database in France to properly document and disseminate information on missing persons and to centralize the biological profile of unidentified bodies is key, as without antemortem information or a biometric database there can be no matching.