Estimation of the pre-burning condition of human remains in forensic contexts

The determination of the original condition of human remains prior to burning is critical since it may facilitate the reconstruction of circumstances surrounding death in forensic cases. Although the use of heat-induced bone changes is not a completely reliable proxy for determining pre-burning conditions, it is not completely devoid of potential, as we can observe a clear difference in the occurrence of such features between the fleshed and dry bones. In order to quantify this difference and determine its true value for forensic research, the frequencies of heat-induced warping and thumbnail fractures were documented on modern cremations of cadavers from recently deceased individuals and from the cremations of skeletons previously inhumed. The effect of age, sex, time span from death to cremation, duration and temperature of combustion on those frequencies was statistically investigated. Results demonstrated that the heat-induced features were significantly more frequent in the sample of cadavers. In addition, warping was determined to be the most useful indicator of the pre-burning condition of human remains. Temperature of combustion was the only variable having a significant effect on the frequency of both features, suggesting that fluctuation of temperature, along with collagen preservation and recrystallization of the inorganic phase, is paramount for their occurrence. Both warping and thumbnail fractures may eventually be used for the estimation of the pre-burning condition of human remains in lack of other indicators, but their reliability is far from absolute. Ideally, such inference must be supported by other data such as skeletal representation, objects or defleshing marks on the bones.