Davide Porta

Unidentified bodies and human remains: An Italian glimpse through a European problem

The identification of cadavers (the main activity of forensic odontologists and anthropologists) is a crucial issue in forensic pathology, but the official entity of this problem is still poorly known in most countries, apart from a few American reports. In this article the authors present a descriptive study of unidentified decedents over a 14-year period (1995-2008) in Milan. The number of cadavers or human remains arriving at the morgue with no identity amounts to 454 - 3.1% of all autopsies at the Institute of Legal Medicine, with a mean of 32 unidentified subjects every year; 62% reached a positive identification in a period of time ranging from a few days to 10 years. 17% on an average remain unidentified. Most identification processes involved forensic odontology and anthropology. This study aims at revealing the problem and hopefully may provide some food for thought for forensic pathologists, anthropologists and odontologists so that they may focus on this issue and on possible solutions in their countries.

Detection of blunt, sharp force and gunshot lesions on burnt remains : a cautionary note

The study of skin and bone lesions may give information concerning type and manner of production, but in burnt material modification of tissues by the high temperatures may considerably change the morphological characteristics of the lesions. This study aims at pointing out the effects of burning head of pigs with several types of lesions (blunt trauma, sharp force, and gunshot lesions) on soft tissues and bones, both from a morphological and chemical point of view. Results show that the charring process does not completely destroy signs of lesions on bones, which can often be recovered by cleaning bone surface from charred soft-tissue residues. Furthermore, neutron activation analysis test proved that antimony may be detectable also on gunshot entry wounds at the final stages of charring process.

Macroscopic, microscopic, and chemical assessment of gunshot lesions on decomposed pig skin.

Abstract:  Very little literature exists on gunshot wounds on decomposed material. In this study, seven pig heads underwent a shooting test. Entrance wounds from the first head underwent neutron activation analysis (NAA) and histological testing immediately after the firing test; the other six heads were exposed to two different environments (open air and soil) and analyzed by radiochemical and histological tests every 15 days. Gunshot wounds in air maintained their morphological characteristics, and those in soil showed severe alteration after 5 weeks. Microscopic testing verified positive results for lead in all gunshot wounds in open air, whereas in most of those in soil lead could not be detected. Radiochemical analysis performed by NAA yielded for all gunshot wounds but one antimony quantities in the range of 0.07–13.89 μg. In conclusion, it may be possible to detect residues of antimony even in degraded tissues.

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.

Personal Identification of Cadavers and Human Remains

Personal identification is a field where pathology, anthropology, odontology, and even genetics must merge. Specific features and descriptors (such as scars, moles, gross anomalies) may be sufficient for identification. However, in more complex cases, four main disciplines are involved in the identification of human remains: DNA, fingerprint analysis, odontology, and anthropology (or better yet, osteology). Genetic and fingerprinting methods give a quantitative result, or at least statistics have been performed on the specific traits studied, which allow one to answer in a quantitative manner on the probability of two individuals having similar characteristics in the first case, for the distribution of different alleles within a population, and in the second, for the frequency of minutiae on the finger. Forensic anthropology and odontology methods, which compare the status and shape of teeth and bones, are valid alternative methods. Methods include comparison of dental work, bone, and tooth morphology, in particular frontal sinus patterns, and craniofacial superimposition. They are advantageous methods because faster and less costly; however, they may suffer, in the view of some judges, from the qualitative and nonquantitative responses they give.

The importance of an anthropological scene of crime investigation in the case of burnt remains in vehicles: 3 case studies

Inspection of a crime scene is a crucial step in forensic medicine, and even the methods taught by forensic anthropology are essential. Whereas a thorough inspection can provide crucial information, an approximate inspection can be useless or even harmful. This study reports 3 cases of burnt bodies found inside vehicles between 2006 and 2009 in the outskirts of Milan (Italy). In all 3 cases, the victim was killed by gunshot, and the body was burnt in the vehicle to destroy signs of skeletal injury and prevent identification. In every case, the assistance of forensic anthropologists was requested, but only after the inspection of the body at autopsy showed that the remains were incomplete, thus making it more difficult to determine the identity, cause, and manner of death. A second scene of crime inspection was therefore performed with strict anthropological and adapted archeological methods by forensic anthropologists to perform a more complete recovery, proving how much material had been left behind. These cases clearly show the importance of a proper recovery and of the application of forensic anthropology methods on badly charred bodies and the importance of recovering every fragment of bone: even the smallest fragment can provide essential information. Thus, a precise coordination, a correct and thorough recovery of bone fragments, and an anthropological approach are crucial for many issues: analysis of the scene of crime, reconstruction of the corpse, and reconstruction of the perimortem events.

Metrical assessment of cutmarks on bone: Is size important?

Extrapolating type of blade from a bone lesion has always been a challenge for forensic anthropologists: literature has mainly focused on the morphological characteristics of sharp force lesions, whereas scarce indications are available concerning the metrical assessment of cut marks and their correlation with the size of blade. The present study aims at verifying whether it is possible to reconstruct the metrical characteristics of the blade from the measurements taken from the lesion. Eleven blades with different thickness, height and shape were used for this study. A metallic structure was built, in order to simulate incised wounds and reiterate hits with the same energy. Perpendicular and angled tests were performed on fragments of pig femurs, in order to produce 110 lesions (10 for each blade). Depth, height and angle were measured and compared with metrical characteristics of each blade. Results showed a wide superimposition of metrical characteristics of width and angle of lesions regardless the type and the orientation of blade: for symmetric blades a high correlation index was observed between the depth of the lesion and the angle of the blade in perpendicular tests (0.89) and between the angle of lesion and the height of the blade in angled tests (-0.76); for asymmetric blades in both the tests a high correlation was observed between the angle of the blade and angle and width of the lesion (respectively 0.90 and 0.76 for perpendicular tests, and 0.80 and 0.90 for angled ones). This study provides interesting data concerning the interpretation of cutmarks on bone and suggests caution in assessing the size of weapons from the metrical measurements of lesions.

Distinguishing between perimortem and postmortem fractures: are osteons of any help?

The distinction between perimortem and postmortem fractures in forensic anthropology is still a frequently unsolved issue. In the present study, we try to verify if there are differences in the pattern of osteon fracturing between fresh and dry bone which could be used for such a diagnosis. Fresh and dry long bones were fractured by a hammer at the mid-shaft perpendicularly to the long axis of the bone and the fracture margins examined under a light microscope as undecalcified sections. Examination of 982 osteons (505 fresh, 477 dry) showed that twice as often the fracture line crosses the osteons as opposed to travelling around them, independently of whether the bone is fresh or dry. Statistical analysis confirmed that there was no significant difference between fresh and dry bone. This seems to imply that osteon fracture pattern cannot help in the diagnosis of perimortem versus postmortem bone fractures. Further research however must be performed concerning fast and slow energy dispersal which may have an influence on the type of fracture inflicted.

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.

Scene-of-crime analysis by a 3-dimensional optical digitizer: a useful perspective for forensic science.

Analysis and detailed registration of the crime scene are of the utmost importance during investigations. However, this phase of activity is often affected by the risk of loss of evidence due to the limits of traditional scene of crime registration methods (ie, photos and videos). This technical note shows the utility of the application of a 3-dimensional optical digitizer on different crime scenes. This study aims in fact at verifying the importance and feasibility of contactless 3-dimensional reconstruction and modeling by optical digitization to achieve an optimal registration of the crime scene.