The impact of climate change and sustainability initiatives on forensic practice.

The climate change crisis affects all aspects of our lives, and this includes national and global scientific endeavours. The forensic sciences are no different but are yet to engage meaningfully with this agenda or to consider what it means for future practice. This paper explores and discusses a range of impacts on forensic and crime scene practice derived from climate change and proposes the potential implications. The paper concludes by laying out a way forward and a programme of activity to support the forensic sciences to manage the implications of climate change and related sustainability initiatives on the criminal and medico-legal investigative community.

The effect of different imaging techniques for the visualisation of evidence in court on jury comprehension.

Evidence presented within a courtroom should be clear so that the members of the jury can understand it. The presentation of distressing images, such as human remains, can have a negative effect on the jury since photographic images may evoke emotional responses. Therefore, it is important to understand how other visual mediums may improve comprehension, bias, or distress individuals. For this study, 91 individuals were randomly assigned one of three visual evidence formats in a mock courtroom exercise. These included photographs, 3D visualisations, or a 3D-printed model. The results show that the use of 3D imaging improves the juror's understanding of technical language used within a courtroom, which in turn better informs the juror's in their decision-making.

A new method for the recovery and evidential comparison of footwear impressions using 3D structured light scanning.

Footwear impressions are one of the most common forms of evidence to be found at a crime scene, and can potentially offer the investigator a wealth of intelligence. Our aim is to highlight a new and improved technique for the recovery of footwear impressions, using three-dimensional structured light scanning. Results from this preliminary study demonstrate that this new approach is non-destructive, safe to use and is fast, reliable and accurate. Further, since this is a digital method, there is also the option of digital comparison between items of footwear and footwear impressions, and an increased ability to share recovered footwear impressions between forensic staff thus speeding up the investigation.

A case of semi-combusted pregnant female in the Phoenician-Punic necropolis of Monte Sirai (Carbonia, Sardinia, Italy).

We present a case of a pregnant woman with the fetus skeletal remains in situ, belonging to the Phoenician-Punic necropolis of Monte Sirai (Sardinia, Italy). The burial dates back to the late 6th to early 5th century BCE. Of the unborn fetal cases documented in the literature this is amongst the oldest four and it represents the first documented case of a pregnant woman in the Phoenician and Punic necropolis literature. A physico-chemical investigation of bones combining X-ray diffraction and Fourier transform-infrared spectroscopy suggests that the female skeleton and fetus were subjected to an incomplete heat treatment according to a funerary practice, perhaps limited to the period of early 5th century BCE, that appears to be peculiar to this site.

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.

An RNA-based analysis of changes in biodiversity indices in response to Sus scrofa domesticus decomposition.

Despite emergent research initiatives, significant knowledge gaps remain of soil microbiology-associated cadaver decomposition. Nevertheless, preliminary studies have shown that the vast diversity and complex interactions of soil microbial communities have great potential for forensic applications such as clandestine grave location and postmortem interval estimation. This study investigated changes in soil bacterial communities during pig (Sus scrofa domesticus) leg decomposition. 16S rRNA, instead of the usually applied 16S rDNA marker, was used to compare the metabolically active bacteria. Total bacterial RNA was extracted from soil samples of three different layers on day 3, 28 and 77 after the shallow burial of a pig leg. The V3 region of the 16S rRNA was amplified, analysed by RT-PCR DGGE, and compared with control soil bacterial community profiles. Statistically significant differences in soil bacterial biodiversity were observed. For the control, bacterial diversity (H') and species richness (S) of the three layers averaged 2.48±0.14 (H') and 18.8±2.5 (S), respectively, while for the test soil increases (p=0.027) were recorded between day 3 (H'=2.71±0.02; S=21.3±2.0) and 28 (H'=3.46±0.32; S=60.3±16.9), particularly in the middle (10-20 cm) and bottom (20-30 cm) soil layers. Between day 28 and 77 the diversity and richness then decreased on average for all three layers (H'=3.43±0.20; S=60.0±17.3) but remained higher than on day 3. Thus, responses in soil bacterial profiles and activity to carcass decomposition, detected and characterised by RNA-based DGGE, could be used together with RNA sequencing data, changes in physico-chemical variables (carbon, nitrogen, phosphorus, temperature, redox potential, water activity and pH) and conventional macroecology markers (e.g. insects and vegetation), to develop a suite of analytical protocols for different forensic scenarios.

Osteometric sex determination of burned human skeletal remains.

Sex determination of human burned skeletal remains is extremely hard to achieve because of heat-related fragmentation, warping and dimensional changes. In particular, the latter is impeditive of osteometric analyses that are based on references developed on unburned bones. New osteometric references were thus obtained which allow for more reliable sex determinations. The calcined remains of cremated Portuguese individuals were examined and specific standard measurements of the humerus, femur, talus and calcaneus were recorded. This allowed for the compilation of new sex discriminating osteometric references which were then tested on independent samples with good results. Both the use of simple section points and of logistic regression equations provided successful sex classification scores. These references may now be used for the sex determination of burned skeletons. Its reliability is highest for contemporary Portuguese remains but nonetheless these results have important repercussion for forensic research. More conservative use of these references may also prove valuable for other populations as well as for archaeological research.

A comparison of surface features on submerged and non-submerged bone using scanning electron microscopy.

Skeletal remains are excellent sources of information regarding the deceased individual and the taphonomic history of their body. However, the accuracy of this information is governed by our ability to interpret features on the surface of a bone. Little research in this respect has been carried out on remains found in aquatic environments. This study compares damage features created on the surface of modern and archaeological bone found in a seawater environment, to surface features present on unmodified bone, archaeological bone, pathological bone and burned bone. Results show that no similarities with regard to surface pores were identified between submerged modern bone and archaeological, pathological and burned bone. Similarities were seen between submerged and dry archaeological bones. Thus it is argued that the misinterpretation of the taphonomic history of isolated bones recovered from bodies of water should be avoidable in the forensic context.

Metric dimensions of the proximal phalanges of the human hand and their relationship to side, position, and asymmetry.

The anatomy of the proximal phalanges of the human hand has been widely described. Nevertheless, when consulting osteology and anatomy publications, the general opinion of researchers is that siding and allocating the proximal phalanges with regard to finger position is difficult, if not impossible. We provide morphological criteria for determining the side of the proximal phalanges and a metric means of allocating a phalanx to a specific finger. This paper also quantifies the absolute and directional asymmetry found in phalanges within this sample. The sample studied consists of three groups, one modern and two archaeological. To investigate these, three measurements were taken-maximum length, maximum width at the base and maximum width at the head. It was found that phalanges could be assigned correctly to the side and finger of origin in 100% of the cases when the five phalanges of a given hand were present, and that this result dropped to 92% when allocating isolated phalanges. The means of the measurements taken were larger in the modern group and a constant relationship between the greater basal width of the second and the fourth proximal phalanges was found.

Differentiation of serrated and non-serrated blades from stab marks in bone.

Although evidence of sharp-force trauma on the human body, particularly the skeleton, can be extremely useful in providing information regarding the manner and context of death, there is still a lack of necessary detail available to the investigator. Using ribs, radii, scapulae, vertebrae and carpal bones, this study demonstrated that distinctions could be made between the stab marks left by serrated blades and those of non-serrated blades. Low power and scanning electron microscopy were used to record distinctive 'T'-shaped stab marks from non-serrated blades and 'Y'-shaped stab marks from serrated blades. In addition, elemental evidence of the presence of the blade in the stab-mark kerf was recoverable even when no metal fragment was visible.

A novel approach to the visualisation of heat-induced structural change in bone.

A new approach to visualising heat-induced change in bone was attempted. This was an attempt to counter the serious limitations of existing analytical methods yet still allow for the examination of subtle changes that occur due to burning. A new form of Magnetic Resonance Imaging was deemed to fulfil this remit. Preliminary tests were performed and proved successful in creating clear, well-defined images of progressive heat-induced structural changes in bone. The implications for improving our understanding of heat-induced change, and therefore our methods of human identification, are significant.

Heat-induced dimensional changes in bone and their consequences for forensic anthropology.

An understanding of heat-induced transformation of hard tissue is vital before a full interpretation of burned human remains can be successfully achieved. Samples of modem sheep (n = 60) were analyzed resulting in 5440 data points. An experimental approach was undertaken that explored the bi-variable impact of heating temperature and duration of burning. Subsequent heat-induced bone changes included the progression of color from natural through to blue-white, the significant loss of weight, the reduction in mechanical strength, the development of distinct fracture patterns, alterations in the microscopic porosity, substantial alterations in crystalline structure and reduction and expansion in size. Collation and integration of this information demanded a revision of the four stages of heat-induced degradation of bone previously presented by Mayne Correia (1) and Thompson (2). The results demonstrate that heat-induced shrinkage is also accompanied by expansion and that both can be statistically significant. This suggests that anthropological techniques applied to burned bone will likely be detrimentally affected and accuracy will be reduced.

Recent advances in the study of burned bone and their implications for forensic anthropology.

Human identification from burned remains is a common requirement of forensic anthropology, yet the techniques used are devised for use on unmodified bone dimensions. Bone experiences extensive and significant heat-induced alteration which decreases the accuracy and precision of identification methods. An holistic approach to the study of burned bone is adopted and demonstrates the interconnectivity and hierarchy of these changes. It is demonstrated that these changes affect all forms of anthropological technique.

Bone mineral change during experimental heating: an X-ray scattering investigation.

The effects of heating and burning on bone mineral have previously been studied using techniques such as X-ray diffraction (XRD) with the aim of discerning a characteristic signature of crystal change. This would enable a better understanding of alteration to bone mineral during heating, which would in turn impact on the preparation and use of natural bone hydroxyapatite as a biomaterial resource. In addition, this knowledge could prove invaluable in the investigation of burned human remains from forensic and archaeological contexts in cremation and funerary practice. Here we describe a complementary method, small-angle X-ray scattering (SAXS), to determine more accurately the changes to bone crystallite size and shape during an experimental heating regimen. Samples were subjected to controlled heating at 500 degrees C, 700 degrees C, or 900 degrees C for 15 or 45 min. Our results show bone crystallites begin to alter in the first 15 min of heating to 500 degrees C or above. They then appear to stabilise to a temperature-specific thickness and shape with prolonged heating. While the samples heated to lower temperatures or for shorter periods produce XRD traces showing little alteration to the apatite, corresponding information obtained from SAXS shows an early, subtle change in crystal parameters.