Assessing violent mechanical asphyxia in forensic pathology: State-of-the-art and unanswered questions

Mechanical asphyxiation has been a common method used to commit homicide, including femicide, throughout history. A recent report by the United Nations has shed light on the issue of misidentification and concealment of gender-related killings, which makes it difficult to effectively fight against it. Forensic pathologists are frequently asked to examine cases involving suspected asphyxia to determine whether other persons have been involved. Therefore, medicolegal experts must look for signs of occlusion of the oral/nasal orifices, compression of the neck, or specific signs such as the "facie sympathique". There are situations where the physical signs are not distinctive enough to diagnose asphyxia, especially in cases where the individual has limited ability to resist external compression. In such cases, judicial autopsies should include an anatomical dissection of the neck structures through a layer-by-layer progression. It is important to search for the Amussat's sign, e.g., as part of a Forensic Clinical Anatomy approach. Additionally, individual anatomical variations, age or artefactual modifications, must be considered for the correct interpretation of findings. Microscopic examinations could aid in the diagnosis by providing additional findings, and several attempts have been made to identify unique markers of asphyxia through various laboratory techniques such as biochemistry, radiology and miRNA studies. However, no single finding or method has been identified as definitive. In the future, biomedical-legal sciences will have to rely on scientific research and the retrospective case series to provide a scientific framework on which to base their hypothesis, giving weight to evidence in the trial.