Forensic insights into mortality and challenges in post-mortem investigations of homeless individuals: a 10-year study (2014-2024) in Milan, Italy.

Forensic medicine represents a critical socio-health observatory for socially marginalized populations. This study provides the first systematic retrospective forensic analysis of mortality among people experiencing homelessness in Italy. We examined 104 decedents undergoing autopsy in Milan between 2014 and 2024. The annual number of autopsied homeless decedents increased over the study period, peaking in 2023-2024. The majority of deaths occurred in indoor public spaces (45/104, 43.3%), with the remainder in hospitals or green areas, reflecting extreme social marginalization and environmental exposure. Anamnestic data were available for 56/104 cases (53.8%), of whom 42 (75%) had chronic medical conditions, while psychiatric or psychosocial histories were known for 43/104 cases (41.3%). These figures likely underestimate the true burden due to fragmented healthcare access and incomplete documentation. Causes of death were classified as natural (25/104, 24.0%), non-natural (17/104, 16.4%), or undetermined (62/104, 59.6%). Natural deaths, predominantly in middle-aged adults, illustrate accelerated health deterioration associated with homelessness, while non-natural deaths reflect heightened exposure to hazardous urban environments. Undetermined deaths - mainly acute circulatory insufficiency without macroscopic findings - highlight substantial gaps in post-mortem evaluation. Toxicological and histological analyses were rarely performed, revealing procedural and structural constraints that impede accurate cause-of-death determination in socially vulnerable and clinically complex populations. These findings uncover preventable and identifiable patterns of mortality, emphasize the forensic and public health value of comprehensive post-mortem investigation, and call for integrated strategies combining proactive healthcare delivery, harm reduction, and standardized forensic protocols to improve diagnostic accuracy and strengthen mortality surveillance in homeless populations.