Debora Mazzarelli

The difficult task of assessing perimortem and postmortem fractures on the skeleton: a blind text on 210 fractures of known origin.

The distinction between perimortem and postmortem fractures is an important challenge for forensic anthropology. Such a crucial task is presently based on macro‐morphological criteria widely accepted in the scientific community. However, several limits affect these parameters which have not yet been investigated thoroughly. This study aims at highlighting the pitfalls and errors in evaluating perimortem or postmortem fractures. Two trained forensic anthropologists were asked to classify 210 fractures of known origin in four skeletons (three victims of blunt force trauma and one natural death) as perimortem, postmortem, or dubious, twice in 6 months in order to assess intraobserver error also. Results show large errors, ranging from 14.8 to 37% for perimortem fractures and from 5.5 to 14.8% for postmortem ones; more than 80% of errors concerned trabecular bone. This supports the need for more objective and reliable criteria for a correct assessment of peri‐ and postmortem bone fractures.

Detection of metal residues on bone using SEM-EDS—Part II: Sharp force injury

Scanning electron microscopy coupled with X-ray energy dispersive spectrometry (SEM-EDS) is extensively seen in the literature for the improvement of the macroscopic analysis of sharp lesions, but very few indications concerning its real potential in the forensic context, particularly in forensic anthropology, are at the moment available. This paper represents a pilot study for the analysis of the behaviour of metallic residues found on bone after sharp force injury. Fourteen lesions were made on human bone (radius), cleaned of all soft tissues, with seven different sharp tools (three metal instruments, three metal saws and a baked-clay knife). Tools and lesions underwent SEM-EDS. From 3 to 18 particles were detected on each lesion, whose diameter was included between 0.5 and 150 μm. In 58% of cases, particle composition was concordant with the instrument used. The results seem to suggest that sharp force injury frequently leaves relatively few residues on bone, particularly in the case of common types of metal. Saws showed slightly more contamination with other residues than knives, which may be explained by the capability of the saws teeth to retain the residues of previously encountered material. In addition, metal residues related to the tool used to cut the bone were located on the edges/walls of lesions in the case of saw marks, whereas they were more frequently found on the kerf floor in the case of knives/scissors, with the exception of the baked clay knife which when it leaves residues at all, seemed to leave them equally divided between the floor, the edges and the surrounding bone.

The comparative performance of PMI estimation in skeletal remains by three methods (C-14, luminol test and OHI): analysis of 20 cases

When estimating post-mortem interval (PMI) in forensic anthropology, the only method able to give an unambiguous result is the analysis of C-14, although the procedure is expensive. Other methods, such as luminol tests and histological analysis, can be performed as preliminary investigations and may allow the operators to gain a preliminary indication concerning PMI, but they lack scientific verification, although luminol testing has been somewhat more accredited in the past few years. Such methods in fact may provide some help as they are inexpensive and can give a fast response, especially in the phase of preliminary investigations. In this study, 20 court cases of human skeletonized remains were dated by the C-14 method. For two cases, results were chronologically set after the 1950s; for one case, the analysis was not possible technically. The remaining 17 cases showed an archaeological or historical collocation. The same bone samples were also screened with histological examination and with the luminol test. Results showed that only four cases gave a positivity to luminol and a high Oxford Histology Index (OHI) score at the same time: among these, two cases were dated as recent by the radiocarbon analysis. Thus, only two false-positive results were given by the combination of these methods and no false negatives. Thus, the combination of two qualitative methods (luminol test and microscopic analysis) may represent a promising solution to cases where many fragments need to be quickly tested.

Dismemberment and disarticulation: A forensic anthropological approach.

The dismemberment of a corpse is fairly rare in forensic medicine. It is usually performed with different types of sharp tools and used as a method of concealing the body and thus erasing proof of murder. In this context, the disarticulation of body parts is an even rarer event. The authors present the analysis of six dismemberment cases (well-preserved corpses or skeletonized remains with clear signs of dismemberment), arising from different contexts and in which different types of sharp tools were used. Two cases in particular showed peculiar features where separation of the forearms and limbs from the rest of the body was performed not by cutting through bones but through a meticulous disarticulation. The importance of a thorough anthropological investigation is thus highlighted, since it provides crucial information on the manner of dismemberment/disarticulation, the types of tools used and the general context in which the crime was perpetrated.

Assets and pitfalls of chemical and microscopic analyses on gunshot residues in skeletonized bodies: a report of five cases

In case of gunshot wounds, forensic anthropologists and pathologists have many tools at hand, and the assistance that chemical and microscopic investigations can provide in such scenarios is often valuable and crucial. However, the results of such analyses in the search of gunshot residues (GSR) ought not to be acritically considered. We report five cases where chemical (sodium rhodizonate) and microscopic (scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX)) analyses were performed for the search of GSR. Four cases concerned the forensic field and analyses on buried, charred, or submerged remains, whereas one case concerned the historical remains of a soldier of the First World War. In every case, the search for GSR with these techniques showed their persistence even after long periods and preservation in peculiar environments. However, chemical analyses provided their contribution, but in two cases, anthropological analyses provided crucial and solving results. The five cases show the indisputable usefulness of chemical and microscopic analyses in the search of GSR in gunshot wounds and especially how such residues may survive in time and in adverse environmental conditions. However, experts should always be dubious about some pitfalls (such as contamination) one can frequently find in these scenarios.

Splitting hairs: differentiating between entomological activity, taphonomy, and sharp force trauma on hair.

PurposeThe analysis of hair can provide useful information for the correct evaluation of forensic cases, but studies of trauma on hair are extremely rare. Hair may present lesions caused by traumatic events or by animals: in fact, signs of sharp force weapons on hair may provide important information for the reconstruction of the manner of death, and, for example, may suggest fetishist practice. This study stemmed from a judicial case where it was fundamental to distinguish between sharp force lesions and insect activity on hair.MethodsIn order to highlight differences between sharp force lesions and insect feeding activity, different experiments were performed with high power microscopy: hair samples were subjected to several lesions by blunt and sharp force trauma; then samples were used as pabulum for two taxa of insects: the common clothes moth (Tineola bisselliella Lepidoptera, Tineidae) and the carpet beetle (Anthrenus sp., Coleoptera, Dermestidae). Hairs were examined from a macroscopic and microscopic point of view by stereomicroscopy and scanning electron microscopy (SEM): the morphological characteristics of the lesions obtained from the different experimental samples were compared.ResultsResults show that sharp force trauma produces lesions with regular edges, whereas insects leave concave lesions caused by their “gnawing” activity. These two types of lesions are easily distinguishable from breaking and tearing using SEM.ConclusionsThis study demonstrates that insect activity leaves very specific indications on hair and sheds some light on different hair lesions that may be found in forensic cases.

Thermal modifications of root transparency and implications for aging: a pilot study.

Root transparency has proven to be related to age and has been considered by different odontological methods for age estimation. Very little is known concerning possible variations of root transparency with heat, although the applicability of the method to burnt remains depends on the possible modifications of this specific variable. This pilot study presents the results of an experiment performed on 105 teeth obtained from dental patients and autopsy material, heated in an industrial oven at 50°C, 100°C, 150°C and 200°C. Root transparency was measured before and after the charring experiment. The heating process proved to radically modify root transparency, which decreased in 20% of samples at 50°C, in 34.6% at 100°C, in 50% at 150°C, in 77% at 200°C. The overall correlation index (CI) between decrease in root transparency and increase in temperature amounted to 0.96. These results show that heat may modify root transparency and suggest caution in using methods based on root transparency for age estimation.

A modern documented Italian identified skeletal collection of 2127 skeletons: the CAL Milano Cemetery Skeletal Collection

The CAL Milano Cemetery Skeletal Collection is a modern and continuously growing identified osteological collection of 2127 skeletons under study in the Laboratorio di Antropologia e Odontologia Forense (LABANOF) in the Department of Biomedical Sciences for Health of the University of Milan (Italy), and part of the Collezione Antropologica LABANOF (CAL). The collection presents individuals of both sexes and of all age groups with a high representation of the elderly and an interesting sample of infants. Each individual is associated with a documentation that includes sex, age-at-death, dates of birth and death, and a death certificate that specifies the exact cause of death and the chain of events that led to it (related pathological conditions or traumatic events). It was also possible to recover for several individuals the autopsy reports and antemortem photographs. This documented osteological collection is of crucial interest in physical and forensic anthropology: it provides unique teaching opportunities and more importantly considerable research possibilities to test and develop sex and age estimation methods, investigate key subjects of forensic relevance and discuss pathological markers, among others. The aim of this paper is to introduce the CAL Milano Cemetery Skeletal Collection as a new identified skeletal collection and present its research and teaching potential.

Study on the criteria for assessing skull-face correspondence in craniofacial superimposition

Craniofacial superimposition has the potential to be used as an identification method when other traditional biological techniques are not applicable due to insufficient quality or absence of ante-mortem and post-mortem data. Despite having been used in many countries as a method of inclusion and exclusion for over a century it lacks standards. Thus, the purpose of this research is to provide forensic practitioners with standard criteria for analysing skull-face relationships. Thirty-seven experts from 16 different institutions participated in this study, which consisted of evaluating 65 criteria for assessing skull-face anatomical consistency on a sample of 24 different skull-face superimpositions. An unbiased statistical analysis established the most objective and discriminative criteria. Results did not show strong associations, however, important insights to address lack of standards were provided. In addition, a novel methodology for understanding and standardizing identification methods based on the observation of morphological patterns has been proposed.

Sex Assessment from the Volume of the First Metatarsal Bone: A Comparison of Linear and Volume Measurements

Sexual dimorphism is a crucial characteristic of skeleton. In the last years, volumetric and surface 3D acquisition systems have enabled anthropologists to assess surfaces and volumes, whose potential still needs to be verified. This article aimed at assessing volume and linear parameters of the first metatarsal bone through 3D acquisition by laser scanning. Sixty‐eight skeletons underwent 3D scan through laser scanner: Seven linear measurements and volume from each bone were assessed. A cutoff value of 13,370 mm3 was found, with an accuracy of 80.8%. Linear measurements outperformed volume: metatarsal length and mediolateral width of base showed higher cross‐validated accuracies (respectively, 82.1% and 79.1%, raising at 83.6% when both of them were included). Further studies are needed to verify the real advantage for sex assessment provided by volume measurements.