Rumor has it: A narrative review on the use of skeletal non-metric traits and variants for personal identification

The human skeleton displays an immense array of traits and variant features that are elements of inter-individual variability. The general assumption is that they may represent individualizing markers for the personal identification of unidentified decedents, but very few works consider them as such. This review provides an overview on the possible use of non-metric traits and skeletal variants for personal identification. The paper discusses the issues related to unquantified comparisons, then it presents a statistical approach based on frequencies of these features for identifying unknown remains. Narrowing down an initial number of 1000 papers, the core of the review is represented by 10 papers that considered non-metric traits and skeletal variants as individualizing features, according to both qualitative and quantitative assessments. Despite visual examination remains the gold-standard, more sound methods are requested to quantify the strength of a match or a mismatch. This especially applies in the wake of juridical demands, hence also satisfying the desire of prosecutors and judges to rely on a “quantified” risk. To this purpose, non-metric traits and skeletal variants seem to be a suitable tool to provide quantified evidence, when related frequencies are known.