Agostino Rizzi

Gunshot residues on dry bone after decomposition--a pilot study.

Abstract:  Very little literature exists concerning radiochemical and microscopic analyses of gunshot wounds in decomposed material, and even less concerning skeletonized samples; the most advanced technologies may provide useful indications for the diagnosis of suspect lesions, especially if gunshot wounds are no longer recognizable. However, we know very little of the survival of gunshot residues (GSR) in skeletonized samples. This study examined nine gunshot wounds produced on pig heads which then underwent skeletonization for 4 years, and four gunshot entries on human heads from judicial cases which were then macerated to the bone in water; the samples underwent scanning electron microscopy coupled with energy dispersive X‐ray (SEM‐EDX) analysis. Positive results for GSR were observed only in four of the nine animal samples and in all four human samples. Among the human samples, two lesions showed Pb and Sb, one lesion only Pb, and one Pb, Sb, and Ba. This pilot study showed the survival of GSR in skeletal material and therefore the crucial importance of SEM‐EDX analyses on skeletonized material. Further studies are needed in order to ascertain the role of environmental modifications of GSR.

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.

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.

Blood or spores? A cautionary note on interpreting cellular debris on human skeletal remains

The identification of red blood cells on both skeletal human remains and decomposed corpses is of remarkable importance in forensic sciences, irrespective of its diagnostic value; their presence is often perplexing and difficult to interpret especially when in the context of decomposition and taphonomical variables. Some clinical research has focused on the morphological changes of red blood cells over time by scanning electron microscopy (SEM), but no research has investigated whether botanical structures can be confused for red blood cells. Since some literature has recently presumed the detection of erythrocyte-like cells on skeletal remains (even ancient) as surely erythrocytes, and most have never taken into consideration the chance of an origin different from blood, such as botanical, the present study aims at verifying the possibility of confusion between erythrocytes and botanical cells by applying SEM analysis and at highlighting the pitfalls in this particular issue through a test submitted to pathologists and natural scientists asked to discriminate between red blood cells and different vegetal structures (60 images obtained by SEM analysis). The results showed that although there are diagnostic features useful in identifying red blood cells from botanical structures, some spores resulted very similar to decaying red blood cells, which calls for attention and great caution when studying decomposed human remains.

“Aged” autopsy gallstones simulating dry bone context: A morphological, histological and SEM-EDS analysis

OBJECTIVE The aim of this paper is to provide information on the morphology and composition of gallstones based on clinical samples in order to assist paleopathologists and bioarchaeologists in recognizing their presence in archaeological contexts. MATERIALS AND METHODS 270 gallstones were extracted and macerated from autopsies conducted at the Istituto di Medicina Legale in Milan (Italy) in order to simulate a dry bone recovered from archaeological contexts. Morphological, histological, and elemental variation was documented. RESULTS Gallstones vary in size, shape, color and texture. The cross-sectional surface correlates with chemical composition and is a valuable tool for classification into subcategories of stones. Histological analysis can confirm the classification. Elemental analysis yielded a higher frequency of carbon, calcium and phosphorus. CONCLUSIONS Although identification of gallstones in archaeological contexts can be challenging, familiarity with morphological, histological, and elemental variation can assist researchers in the field and laboratory. SIGNIFICANCE Identifying gallstones in archaeological populations will assist researchers in estimating their frequency in the past and the environmental, cultural, and biological conditions leading to their presence. LIMITATIONS Small sample size derived from a modern and limited autopsy population may minimize the types and degree of variation present in the past. Effects of climate, soil, and taphonomy were not evaluated. SUGGESTIONS FOR FURTHER RESEARCH Examination of larger samples derived from diverse populations may reveal greater variation or more diagnostic aspects of stones.

Erratum to: Blood or spores? A cautionary note on interpreting cellular debris on human skeletal remains

Erratum to: Int J Legal Med (2015) 129:919–926