Pre-grouping of commingled human skeletal remains by elemental analysis

When multiple sets of human remains exist in the same context, they can become mixed up, or commingled. Commingling happens because of broad, multifactorial circumstances that affect the postmortem environment ranging from animal scattering to mass burial, or errors during recovery and curation. Sorting commingled remains back into their individual skeletons is challenging and often achieved through using various indicators such as age, sex, post-depositional modification, morphology, and size. Certainty in sorting can only be achieved through DNA testing, which is destructive as well as cost and time prohibitive. An easy to use, accessible technology is needed to support sorting of commingled remains and would be most relevant for professionals in medico-legal, forensic, and archaeological contexts. The purpose of this study is to evaluate Laser-Induced Breakdown Spectroscopy (LIBS) as a useful tool for sorting commingled remains. LIBS technology provides an elemental profile of the material being analyzed, in this case, human bones and teeth. LIBS can determine that unique elemental profile to help sort commingled remains.

The goal of this proposal is to develop a protocol to use the elemental profile obtain by a portable LIBS instrument to sort commingled remains. This project will be led by Dr. Baudelet, sponsor a graduate student (1) at the National Center for Forensic Science (UCF), Dr. Bethard (Anthropology, USF) and Dr. Zejdlik-Passalacqua (FOREST, WCU). This goal will be fulfilled in 3 parts:

Instrumental optimization for a reliable comparison of skeletal remains
Design of a classification to optimize sorting of commingled remains obtained at the FOREST facility
Comparison of the elemental approach with traditional methods of sorting remains

This project will provide the forensic community with its first large scale evaluation of portable LIBS analysis for the sorting of commingled remains. A protocol will be developed and integrated in the instrument that can be used by practitioners. The outcomes of this study will be a preliminary database of elemental profiles of human remains, the protocol to obtain this profile in the field with a portable instrument, and its use for the sorting of commingled human remains, tested against traditional methods for sorting commingled remains by commingling the same sample and asking experienced anthropologists to sort the remains.