The Differential Diagnosis Between Natural Death ...

CASE REPORT

The Differential Diagnosis Between Natural Death and Homicide, an Everlasting Challenge for the Forensic Pathologist An Exemplar Case Report Alessandro di Luca, MD, Valentino de Matteis, MD, Antonio Marcelli, MD, Matteo Polacco, MD, Vincenzo L. Pascali, MD, PhD, and Antonio Oliva, MD, PhD Abstract: Most of the work performed by the forensic expert is to find proof for different plausible hypotheses that may be used in a trial to serve justice purposes when the “identity” of a case is already unveiled. Yet the previous phase of the investigation is also of great importance, and sometimes (like in the presented case), it represents the core element of the entire investigation. The appropriate determination of the differential diagnosis between a natural death and a death of forensic interest (ie, homicide) is the first and crucial step in the classification of a case. This article analyzes the case of the body of a man found lying on the border of a country road with his wrists tied up with rope and the resulting investigation performed by the medicolegal forensic expert. In the end, as more specific examinations where performed aimed to find the truth, the final conclusions excluded a violent death and confirmed that the cause of the death was an acute myocardial infarction. Key Words: CT scan, differential diagnosis, forensic, histology, myocardial infarction, PCR amplification (Am J Forensic Med Pathol 2016;00: 00–00)

CASE REPORT In late autumn, in the typical countryside of the suburban north part of Rome, Italy, the dead body of an Egyptian immigrant was found: face down, with his wrists tied behind the back,1 on the side of a secondary dirt road, not far from an inhabited area (Fig. 1). The police alerted immediately the prosecutor’s office and opened a murder case. The forensic expert arrived shortly after the police and performed an external body inspection together with a first investigation of the crime scene. No solid data were recovered by the ambient analysis. In order to allow the mobilization, and thus the first examination of the body, the rope tying the wrists was cut off and collected as proof for further laboratory analysis. The presence of hypostasis in the regions typical of the prone position was recorded, as the rigidity of all the muscular districts. A vast area of ecchymosis was found on the whole face and on the neck.

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he burden of performing a differential diagnosis between natural deaths and homicides has always been one of the core activities of the forensic expert. As in the majority of cases such difference appears to be quite clear or at least deduced by normal means of expertise that are part of the core competencies of the forensic expert, some cases require some more in-depth investigation and the use of the most renewed knowledge and technologies available. Although the last decade has been characterized by a rigorous policy of cost-efficiency action, especially in the administration of the justice, it is necessary to keep in mind that every case in forensic practice is unique, and no routine may be put into effect in this “line of work.” This means that during a forensic investigation it is mandatory to be aware about the fact that preliminary data may be deceiving and nothing may be assumed without hard proof. The following case was preliminarily considered a homicide. The expertise and professionalism of the forensic expert did not allow him to simply confirm the police findings and let them proceed with the investigation; instead, he treated the case without any external influence, hence arriving to a different conclusion.

Manuscript received March 16, 2016; accepted October 10, 2016. From the Section of Legal Medicine, Institute of Public Health, Catholic University School of Medicine, Rome, Italy. The authors report no conflict of interest. Reprints: Alessandro di Luca, MD, Section of Legal Medicine, Institute of Public Health, Catholic University School of Medicine, Largo F. Vito 1, 00168, Rome, Italy. E-mail: [email protected]. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0195-7910/16/0000–0000 DOI: 10.1097/PAF.0000000000000282

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FIGURE 1. The body, as found by the police. www.amjforensicmedicine.com

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The rectal temperature was also collected, revealing a temperature of 31.4°C and an ambient temperature of 17°C; the examination was repeated 15 minutes later, resulting in 31.1°C of internal temperature and 16.8°C of ambient temperature. The Henssge nomogram method was performed in order to establish the time of death: the death occurred 10 ± 2.8 hours prior to the measurement (Fig. 2).2–5 Circumstantial information recovered by the police revealed that the man was known to the authorities because he had denounced an attempt of extortion performed by some of his acquaintances for a matter of debts. This kind of information gave further value to the homicide hypothesis. The body was then moved to the Institute of Legal Medicine of the Catholic University of Rome for further postmortem examinations. As a first step, prior to the more in-depth external examination and autopsy, a total body computed tomography (CT) scan was performed in the radiology section of the university. The CT scan gave negative results for the presence of bone fractures or signs of lesions. However, signs of sclerosis of the great blood vessels were reported, as well as augmentation of the heart volume (left ventricle) and severe sclerosis of all the coronary vessels (Fig. 3).6 The body was then moved back to the Legal Medicine Section of the university, and a complete postmortem investigation

was performed. The clothes were removed and preserved as evidence for further investigations. The presence of a small lesion on the nasal pyramid and on the right side of the face was recorded, as well as an ovoid lesion on the left knee measuring 2 ! 1 cm; the partial avulsion of a dental prosthesis was also noticed. These findings were reasonably connected to the man’s fall on the ground, because no other sign of violence or struggle was observed during the body examination.7,8 Subungual material was collected in order to find biological traces not belonging to the deceased, as well as a blood samples for comparative purposes. Finally, the autopsy was performed: no internal signs of lesions or trauma were detected. Single organ examination did not reveal any useful information with the exception of the heart. The sclerosis of all coronary vessels, with the decrease n the vessel width (Fig. 4), was clearly visible. The myocardium showed some dichromic areas referable to a possible myocardial infarction.9–11 During the autopsy, samples for histology and genetic investigation from all organs together with bodily fluids for toxicology purposes were collected and processed later on. Wrist skin was also collected, in order to perform histological examinations in order to verify the vitality of the rope marks (Fig. 5).12 As suspected, the histology of the coronary vessels revealed atherosclerotic evidence with signs of calcification, and the

FIGURE 2. Henssge’s normogram.

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Natural Death and Homicide

FIGURE 5. Sampling of the skin fragments where the rope was tied.

myocardium showed the typical signs both of previous heart attacks and evidence of a late acute infarction consisting in signs of a vast area of coagulation necrosis (Fig. 6). Sections of the other organs revealed only congestion and a small amount of edema. Small portions of the lungs showed evidence of emphysema. Furthermore, no specific signs of smothering were found during all the phases of the investigation, as confirmed by the data collected during the CT scan (for instance, no sign of trauma of the organs of the neck). Most interestingly, the skin samples collected from the wrists— where the rope signs were evident—game completely negative results on the account of the vitality of the lesions; no red blood cell extravasation was detected, and there was no traumatic degeneration of the collagen (Fig. 7). This unexpected data were the strong evidence that proved that the body’s wrists were oddly tied up only after death. The genetic investigation was performed on the biologic traces found on the clothes of the deceased—after observation with mini

Crimescope 400 (Mini-Crimescope, SPEX Forensics, Edison, NJ)— on the rope and on the collected subungual material. Preliminary analysis with the RSID–Blood Galantos Genetics kit (Galantos Genetics GmbH, Mainz, Germany) was also performed, confirming that all the traces found were of hematic origin. The DNA extraction was performed by the use of a PrepFiler kit (Fisher Scientific Italia, Rodano, Italy) following a standard protocol. All the aforementioned procedures were performed in a sterile facility in order to avoid any kind of possible contamination of the samples by external agents. Quantification of the extracted material was performed by real-time polymerase chain reaction applied to the Applied Biosystems 7500 Real Time PCR (Fisher Scientific Italia, Rodano, Italy) using the Investigator ESSplex SE Plus kit (QIAGEN S.r.l., Milan, Italy). The analysis was performed with the Quantifiler Human DNA Quantification Kit (Fisher Scientific Italia, Rodano, Italy). Except for a very small quantity of material that did not allow the extraction of a genetic profile, all the remaining DNA recovered from all the examined samples was attributable to the deceased man. Chemical-toxicological analysis of the body fluids (blood, bile, vitreous liquid, and urine), in order to identify drugs or alcohol, gave negative results as well. After receiving the whole report given by the forensic pathologist, the prosecutor closed the case as a natural death. This decision was justified by the fact that there was a complete absence of

FIGURE 4. Autopsy finding of the sclerosis of a coronary vessel.

FIGURE 6. Histology of the myocardial infarction.

FIGURE 3. Computed tomography scan showing the calcification of the coronary vessels.




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essential in many cases. In terms of justice expenses, the forensic expert must also keep in mind that all his/her work will have a cost for the entire community. The present article is not a plea to conduct every expensive and useless examination at disposal, but it is intended as a reminder for the independence of thought of the forensic professional. Examinations must be conducted if necessary, regardless of costs, because on such investigation lays partially the security of the society and the correct functioning of the legal system. Yet, there are no fixed rules or precise guidelines on borderline cases. In the end, it all comes to personal skill, intuition, and expertise in order to determine the correct approach to a case. This remains the difficulty and the beauty of the challenge provided by the forensic profession.

REFERENCES FIGURE 7. Histology of the skin samples of the wrists.

evidence leading to violence and the autopsy finding of a natural cause of death. The cardiac infarction was confirmed by the CT scan, the macroscopically visible findings, and the histological examination of the myocardium and heart vessels. The reason behind the fact that a dead man had been tied up was beyond the aims of the forensic expert’s investigation and was left to the police force. It is yet plausible that the hands were tied, after the death (as proven by histological investigations), in order to allow a simpler translation of the body in an attempt to hide it. It may certainly be not excluded that the cardiac infarction might have been caused by an event immediately before the death (as a menacing behavior by the “aggressors”), but there was no proof that corroborates such thesis. Reality is often more complex than fiction, yet scientific evidence is the only proof necessary, and it may not be ignored in order to justify the inexplicable.

DISCUSSION This case illustrates how the correct methodology and the scrupulous scientific approach are a fundamental tool for the forensic pathologist, especially in cases that appear, at a first glance, as clear homicides. The research of the truth is at the basis of the forensic investigation; hence, an open mind together with the knowledge of the possible examinations that may be performed for a correct differential diagnosis is essential on behalf of the forensic expert in order to avoid useless police investigations and, in the worst cases, the incrimination of an innocent. As previously stated nothing can be assumed as correct until it is not proven right by hard scientific evidence, it is the role of the forensic to “see with his own eyes”; that—not by a mere case—is also the meaning of the word “autopsy.” During the last years, the autopsy has become only the preliminary phase of a much wider array of examinations that are

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