Commingled skeletal remains found in a bulk bag: a case report on forensic and archaeological differentiation.

The discovery of human skeletal remains in non-burial settings often triggers immediate criminal investigations. When forensic pathologists lack sufficient anthropological training, differentiating between forensic and archaeological remains becomes challenging, potentially leading to unnecessary judicial costs. This case report highlights the critical role of forensic anthropology in determining post-mortem intervals and guiding judicial decisions. CASE DESCRIPTION: Four industrial bulk bags were illegally dumped at a suburban car dealership. Three contained construction waste, and one contained numerous human bones mixed with soil. Forensic pathologists and anthropologists conducted collaborative examinations. Visual inspection revealed advanced bone deterioration, uniform dark brownish soil staining, and absence of modern medical treatment for healed femoral fractures. In one of the skulls, numerous plant fibers were attached to the palatal vault and nasal cavity, consistent with Edo period (17th-19th centuries) burial customs. Furthermore, dental radiographic examinations confirmed the lack of modern treatments. Thus, the black metallic staining of the teeth and endocranium was considered to be a taphonomic change caused by the deposition of metals from the environment, particularly Mn and Fe, over an extended period. Finally, radiocarbon dating definitively calibrated the chronological range of the remains from the mid-17th to mid-20th centuries. CONCLUSION: The findings confirmed that the remains were archaeological rather than forensic, likely excavated from an old burial site during construction and illegally discarded. This case underscores the importance of basic anthropological knowledge regarding taphonomic changes for forensic experts to rapidly differentiate historical remains from active criminal cases.