Limbs found in water: investigation using anthropological analysis and the diatom test

We report the investigation, using a multi-disciplinary approach, of five cases of dismembered limbs which were recovered from Lake Ontario, Lake Erie and the Niagara River, and examined at the Office of the Chief Coroner for Ontario. In all cases, postmortem examination revealed that the limbs had been disarticulated in the postmortem period, by non-human taphonomic processes. In addition to routine gross examination, the femur and/or tibia were assessed using anthropological methods to give estimates of the sex, age, race and stature of the individual. The anthropologic data facilitated the identification of one of the cases. In all cases, nitric acid extracts of the femoral bone marrow were prepared and examined for the presence of diatoms. In all instances, diatom frustules were recovered from marrow extracts, indicating that drowning was the cause of death or at least a significant contributing factor in the cause of death. The use of the diatom test was helpful in excluding the possibility that the limbs were dismembered from individuals who had died by means other than drowning, and had been subsequently 'dumped' into water. The application of anthropological methods and the diatom test for drowning may significantly enhance the medico-legal investigation of body parts recovered from water, and we present an overview of useful techniques here. Anthropological data may facilitate identification, and the diatom test may establish a cause of death.