How taphonomic alteration affects the detection and imaging of striations in stab wounds

Stabbing with a kitchen knife is a common methodof homicide in Europe. Serrated knives may leave tool mark-ings (striations) in tissues. Documentation of striations is nec-essary for their use as forensic evidence. Traditional methods(physical casting and photography) have significant limita-tions, and micro-computed tomography (micro-CT) has beentrialled in cartilage toBvirtually cast^wounds. Previous re-search has shown the proportion of striations in cartilage fallsfollowing decomposition. This project has investigated theeffects of taphonomic alteration and documentation methodsof striations in porcine skin. Fresh, decomposed, mummified,burnt and waterlogged stab wounds in a porcine analoguewere excised and imaged using photography, stereo-opticalmicroscopy and micro-CT. The proportion of striations ineach taphonomic group was determined from the images byindependent analysts. Striations were observed more frequent-ly in serrated blade wounds, although they were also identifiedin non-serrated blade wounds. The proportion of woundsshowing striations declined following decomposition. An in-versely proportional linear correlation between advancing de-composition and proportion of striations existed. Dehydration(mummification and burning) rendered serrated and non-serrated blade wounds indistinguishable. Water compositionaffected the preservation of striations. Identification ofstriations gradually declined after decomposition in tap water,but persisted to a point when left in brackish water. All threetechniques imaged striations; however, the optimum tech-nique was stereo-optical microscopy due to practical advan-tages and specific limitations affecting photography and mi-cro-CT. This study demonstrates the effects of taphonomicalteration on striations and suggests stereo-optical microscopyis the optimum method for their documentation

A minimum data set approach to post-mortem computed tomography reporting for anthropological biological profiling

Anthropological examination of bones is routinely undertaken in medico-legal investigations to establish an individual’s biological profile, particularly their age. This often requires the removal of soft tissue from bone (de-fleshing), which, especially when dealing with the recently deceased, is a time consuming and invasive procedure. Recent advances in multi-detector computed tomography have made it practical to rapidly acquire high-resolution morphological skeletal information from images of “fleshed” remains. The aim of this study was to develop a short standard form, created from post-mortem computed tomography images, that contains the minimum image-set required to anthropologically assess an individual. The proposed standard forms were created for 31 juvenile forensic cases with known age-at-death, spanning the full age range of the developing human. Five observers independently used this form to estimate age-at-death. All observers estimated age in all cases, and all estimations were within the accepted ranges for traditional anthropological and odontological assessment. This study supports the implementation of this approach in forensic radiological practice