C14 vs everything else: the disturbing comparison in dating skeletal remains

In forensic anthropology the estimation of PMI (Post Mortem Interval) is a crucial issue, which brings about relevant logistic issues. The only method able to give a numerical result on bones is the radiochemical test based on the analysis of C14, although it is more expensive and can be performed by few laboratories. On the other hand, other methods, such as Luminol, UV tests and histological analysis, can be performed as preliminary investigations, and allow the operators to gain a fast result concerning the PMI of the recovered bones, but they lack scinetific accreditation. Nonetheless they may provide some help as they are inexpensive and can give a fast result, especially in the preliminary investigations where the correct estimation of time since death has a crucial importance in orienting further steps of analysis. This presentation aims at showing the validity of macroscopic, microscopic, Luminol and UV tests on 19 real cases (and several modern and ancient populations) concerning recovered bones in comparison with radiochemical tests. In all samples the radiocarbon analysis was first performed in order to reach a quantitative result; then macroscopic, microscopic, luminol and UV tests were applied. Their results were then compared with those provided by the radiochemical method. The radiocarbon analysis gave a successfull and reliable result in all case but one, as expected. All other methods showed enormous limitations and both false positive and negative results. The results thus suggest caution in using qualitative methods as a screening test in order to distinguish between archaeological and forensic cases; in addition, whereas a negative result is more often concordant with an archaeological origin, a positive outcome by qualitative methods must be confirmed by radiochemical tests in order to reach a precise estimation of PMI.