Use of qualitative and quantitative techniques in the resolution of a small-scale medicolegal case of commingled human remains

In 2015, a Florida forensic anthropology laboratory received a commingled assemblage of human remains (one female, one male) recovered from a freshwater context. We used qualitative and quantitative methods to sort the commingled skeletal elements into discrete individuals prior to conducting more in-depth anthropological analyses. Qualitative sorting methods included comparing morphological similarities between paired and/or associated skeletal elements, assessing the fit of anatomical articulations, and matching skeletal elements with consistent secondary sexual characteristics. Quantitative methods included osteometric sorting (which allowed the individual assignment of measured skeletal elements to be supported or rejected) and portable X-ray fluorescence (pXRF) spectrometry (which established chemical elemental profiles for the individuals, potentially enabling the assignment of unattributed remains to one individual or the other). In general, quantitative analyses supported the qualitative segregation. No quantitative analysis rejected an original qualitative assignment. However, there were instances when the quantitative analyses failed to segregate skeletal elements into discrete individuals, even when qualitative segregation was clearly indicated. Further, pXRF failed to differentiate between the individuals, likely due to diagenetic alteration of all remains. Ultimately, the quantitative analyses supplemented, but could not replace, qualitative analyses in the resolution of this small-scale case of commingling. Both approaches are warranted.