MDCT analysis of projectile injury in forensic investigation

OBJECTIVE: This article illustrates the MDCT postmortem imaging features that have the potential to enhance forensic investigation and conventional autopsy. CONCLUSION: MDCT may guide, direct, or limit forensic autopsy in projectile injury cases, thereby eliminating the need for a complete invasive autopsy.     

Applied forensic epidemiology: The Bayesian evaluation of forensic evidence in vehicular homicide investigation

The comparative weighting of evidence in a criminal case can be a complicated task when the relevance or meaning of the evidence is disputed. An example of this complexity in seen in vehicular homicide investigations in which the identity of the driver (and thus the guilty party) is not clear. The discipline of Forensic Epidemiology, including the appropriate application of Bayes’ Theorem (Bayes’ Law) provides a systematic framework to bring clarity to the evaluation of such matters. Bayes’ is a useful tool for the conditioning and quantification of probabilities associated with evidence in a vehicular homicide investigation. The authors present a case study in the application of Bayes’ Theorem to the facts in a vehicular homicide investigation. An initial analysis of the crash dynamics in comparison with the injury pattern and ejection status of the surviving occupant versus that of the decedent suggested that the survivor was the driver. The results of the analysis were used as tests for guilt, with estimated true and false positive rates, which then formed the basis for a Bayesian calculation of the posterior probability of the survivor’s guilt given the evidence. As a result of the Bayesian analysis described herein, it was determined that the survivor was 19 times more likely to have been the driver, in comparison with the decedent. This ratio far exceeded the suggested threshold of 10:1 for establishing the guilt of the survivor beyond a reasonable doubt. When used properly, Bayes’ Theorem can offer definitive insight in the investigation and prosecution of vehicular homicide cases.     

Who is who? Identification of livestock predators using forensic genetic approaches

Molecular identifications of salivary DNA are increasingly applied in wildlife forensic investigations, and are successfully used to identify unknown livestock predators, or elucidate cases of large carnivore attacks to humans. In Europe most of livestock predations are attributed to wolves (Canis lupus), thought free-ranging dogs are sometime the responsible, and false predations are declared by breeders to obtain compensations. In this study we analyzed 33 salivary DNA samples collected from the carcasses of 13 sheep and a horse presumably predated by wolves in seven farms in central Italy. Reliable individual genotypes were determined in 18 samples (corresponding to samples from nine sheep and the horse) using 12 unlinked autosomal microsatellites, mtDNA control-region sequences, a male-specific ZFX/ZFY restriction-site and four Y-linked microsatellites. Results indicate that eight animals were killed by five wolves (a male and four different females), the ninth by a female dog while the horse was post-mortem consumed by a male dog. The genotype of one female wolf matched with the genetic profile of a female wolf that was non-invasively sampled 4 years before in the same area near livestock predation remains. Genetic identifications always supported the results of veterinary reports. These findings show that salivary DNA genotyping, together with detailed veterinary field and necropsy reports, provides evidence which helps to correctly identify species, gender and individual genetic profiles of livestock predators, thus contributing to clarify attack dynamics and to evaluate the impact of wolf predations on husbandry.     

Suitability of PCR methods for forensic investigation

Summary The PCR method has been applied to amplify a Variable Number Tandem Repeat (VNTR) sequence located at the 3 end of the apolipoprotein B (ApoB) gene. The study was conducted on an Italian population sample and in a 3-generation family of 13 members, whose relationships were previously established using conventional blood systems. The allele frequencies found were compared with those reported in the literature. The results also confirmed the Mendelian inheritance of the alleles and the suitability of the PCR method for forensic purposes.     

von Willebrand factor in cadaveric urine for forensic investigation

Preliminary experimental study of urinary von Willebrand factor (VWF) concentration was undertaken to evaluate the utility of this parameter in forensic investigations. ELISA was used to measure VWF concentration. Correlations of urinary VWF with cause of death and postmortem interval (PMI) were ascertained. As PMI advanced, urinary VWF increased but plasma VWF did not. Cause of death was not significantly correlated with VWF. This study indicated the possibility that urinalysis would be helpful to estimate PMI.     

Freezing preparation for macroscopic forensic investigation in putrefied brain

PurposeTo evaluate the usefulness of the applied freezing technique in putrefied brain for macroscopic investigation.Materials and methodsFrom October 2015 to September 2016, first the brains of 10 cadavers (control group: male 6, female 4, age 20–80 (mean 61.5), postmortem intervals (PMI) 14–75 (mean 29.7) days) were inspected following the standard practice (without freezing preparation), and then with 10 cadavers (freezing group: male 7, female 3, age 41–88 (mean 60.4), PMI 7–75 (mean 29.2) days) the freezing technique was used before the autopsy. The cut brain was investigated, and the gray-white matter difference was evaluated macroscopically.ResultsIn the control group, the brain parenchyma leaked out like sludge in 5, and there was difficulty maintaining its structure in 7. The gray-white matter difference was well visible in 3, but hard to distinguish in 3, and the total scores ranged from 0 to 9 (mean 4.4) points. In the freezing group, the entire putrefied brain was extracted as a solid organ, the gray-white matter differences were well visible, and the total scores were 6.7–9 (8.3) points. The gray-white matter difference was preserved in the freezing group (p < 0.05).ConclusionThe freezing procedures to evaluate the putrefied brain have been successfully applied, and it could be statistically more useful in putrefied brain investigation than the ordinary procedure. Postmortem CT can be useful to evaluate not only the degree of brain putrefaction, but also the degree of brain parenchyma freezing.     

Immunohistochemical investigation of hypoxiclischemic brain damage in forensic autopsy cases

A neuropathological study of 41 forensic autopsy cases of hypoxic/ischemic brain damage has been undertaken, using immunohistochemical staining to detect the 70-kDa heat shock protein (hsp70) and the status of the glial cells. In cases surviving 2–5 h after hypoxic/ischemic injury, ischemic cell changes were seen whereas glial reactions were not apparent. In cases of longer survival, neuronal necrosis and a loss of neurons were seen, and these changes were accompanied by proliferation of glial fibrillary acidic protein (GFAP), vimentin-positive astrocytes and microglia which transformed into rod cells or lipid-laden macrophages. In cases with a history of hypoxic attacks, GFAP-positive and vimentin-negative astrocytes had proliferated in the CA3 and CA4 regions of hippocampus. The cases of severe hypoxic injury, such as an asthmatic attack and choking, showed no ischemic changes in the hippocampul neurons. On the other hand, the CA1 pyramidal cells showed neuronal necrosis in a patient suffering from tetralogy of Fallot (TOF), who survived for 2 h after a traffic accident. Therefore, it is suggested that even moderate hypoxic injury induces astrocytosis in the CA3 and CA4 regions and may affect the neuronal proteins and the metabolism, and that in cases with a history of hypoxic attacks neuronal damage may be severe even several hours after ischemic injury. The protein hsp70 expression was found in the CA2, CA3 and CA4 regions in cases of long-term survival after severe hypoxic/ischemic injury and in cases of alcoholic intake or toluene abuse just before acute death. Thus, it is suggested that the detection of hsp70 in the hippocampus indicates hypoxic/ischemic injury or other stress prior to death. In forensic practice, immunohistochemical investigation of the hsp70 and glial cell staining can be of great value for diagnosing not only hypoxic/ischemic brain damage during the process of death but also the victim's past history of hypoxic attacks.     

Developing a strategic forensic science risk management system as a component of the forensic science system of systems

ABSTRACT

Over the last decade, reviews of the forensic science industry have addressed critical system failures and made recommendations for improvements to the industry. These reviews identify systemic risks and issues but they do not explicitly address the need for strategic risk and issue management systems to deal with the identified issues and to mitigate risks. Risk and issue management, along with quality management systems, are critical components of the forensic science ‘system of systems’, which describes forensic science as a supporting system in the larger criminal justice, law enforcement, intelligence, and military systems. The update of ISO 17,025:2017 General requirements for the competence of testing and calibration laboratories now includes a chapter on risk-based thinking. Furthermore, ISO 31,000 principle and guidelines for risk management was updated in 2018 and it is important for the forensic science industry to consider the updated ISO 17,025:2017 and ISO 31,000. In this paper, we discuss risk and issues management in relation to the forensic science system of systems. The purpose is to review the strategic risks identified in reviews of the forensic science industry to identify risk treatments to help to mitigate against critical system failure, such as miscarriages of justice.     

Utility of the caput succedaneum in the forensic investigation of neonaticide: a case report

Suspicion of neonaticide often leads to a request for a forensic autopsy. In that setting, it is important to correlate autopsy findings with the history given by the mother. So far, caput succedaneum has not raised interest in forensic pathology. A caput succedaneum is a haemorrhagic oedema involving the skin and superficial fascia of the head that results from circulatory stasis caused by compression exerted by the uterus or cervix on the presenting part. It is usually seen with prolonged labour. We report a case of caput succedaneum in a forensic autopsy that overturned the mother's history of giving birth suddenly, consequently increasing the evidence of neonaticide.     

The detection of residual gasoline for forensic soil investigation in arson

The cause of an arson fire is difficult to investigate. Detection of gasoline residue can provide important information to link evidence with an arson scene. Soil can be taken as physical evidence from an arson scene and also used to indicate the presence of gasoline residue. Since each soil has different characterisation details, this study was undertaken to present an effective method for soil sampling. Gasoline permeability in soil is affected by soil type. This study investigates the permeation of gasoline into four different soil types and determines the optimum soil depth for gasoline detection. The effect of burning duration and the time between extinguishing the fire and taking the sample were also investigated. The studied soils were collected from various soil series in Thai Northern region. The results indicate that soil structure, burning duration and sampling period are important factors that have a significant effect on residual gasoline detection in each of the soil series studied. The key finding of this study was that the optimum depth for all studied soil series was 5 cm below the surface. These findings have implications for crime scene investigators carrying out soil evidence investigation at an arson scene.     

Applying forensic anthropological data in homicide investigation to the depravity standard

Forensic anthropology can provide detailed information regarding the perpetrator's treatment of a homicide victim. This data may inform The Depravity Standard (DS), a forensic science inventory used to assess the severity of a homicide's intent, actions, victimology, and attitudes. Skeletal data enabled the reconstruction of a homicide case involving mutilation and possible torture. Using The Depravity Standard (DS) the skeletal data underwent evaluation in order to provide evidence of depravity. The osteological data alone offered sufficient evidence for a number of criteria of depravity, demonstrating the importance and application of osteology in resolving specific questions about the depravity of a homicide.     

Relatives' attitudes towards medico-legal investigation and forensic autopsy: a study from South Delhi

Relatives of deceased persons on whose bodies a medico-legal autopsy had been performed at the All India Institute of Medical Sciences, New Delhi, India were personally asked to complete a questionnaire. The aim of study was to determine surviving family members' attitudes towards medico-legal investigation and forensic autopsy. The majority of the relatives showed a positive attitude towards forensic autopsy but were not aware of the detailed procedure of the autopsy. They wanted sufficient information to be provided before the autopsy. They showed a great interest in autopsy results i.e. the cause of death. It was concluded that sufficient relevant explanations given before the autopsy improves the relatives' acceptance and helps alleviate the suffering of the bereaved. The experience and opinions of relatives may help an autopsy surgeon in more effective management of medico-legal cases.     

Principal forensic physicians as educational supervisors

This research project was performed to assist the Faculty of Forensic and Legal Medicine (FFLM) with the development of a training programme for Principal Forensic Physicians (PFPs) (Since this research was performed the Metropolitan Police Service have dispensed with the services of the Principal Forensic Physicians so currently (as of January 2009) there is no supervision of newly appointed FMEs or the development training of doctors working in London nor any audit or appraisal reviews.) to fulfil their role as educational supervisors.PFPs working in London were surveyed by questionnaire to identify the extent of their knowledge with regard to their role in the development training of all forensic physicians (FPs) in their group, the induction of assistant FPs and their perceptions of their own training needs with regard to their educational role. A focus group was held at the FFLM annual conference to discuss areas of interest that arose from the preliminary results of the questionnaire.There is a clear need for the FFLM to set up a training programme for educational supervisors in clinical forensic medicine, especially with regard to appraisal.     

Introduction of concurrent processes into the digital forensic investigation process

Performing a digital forensic investigation requires a formalised process to be followed. It also requires that certain principles are applied, such as preserving of digital evidence and documenting actions. The need for a harmonised and standardised digital forensic investigation process has been recognised in the digital forensics community and much scientific work has been undertaken to produce digital forensic investigation process models, albeit with many disparities within the different models. The problem is that these existing models do not include any processes dealing explicitly with concurrent digital forensic principles. This leaves room for human error and omissions, as there is a lack of clear guidelines on the implementation of digital forensic principles. This paper proposes the introduction of concurrent processes into the digital forensic investigation process model. The authors define concurrent processes as the actions that should be conducted in parallel with other processes within the digital forensic investigation process, with the aim to fulfil digital forensic investigation principles. The concept of concurrent processes is a novel contribution that aims to enable more efficient and effective digital forensic investigations, while reducing the risk of human error and omissions that result in digital evidence being contaminated.     

The paradigm of interdisciplinarity in forensic investigation. A case in Southeastern Spain

The paper presents the procedure followed to fully solve a forensic case which occurred in Southeastern Spain through the collaboration of specialists from different scientific areas belonging to two different government institutions, a public University and the Guardia Civil. Entomological evidence was required to estimate the PMI in order to settle the perimortem circumstances. Piophila megastigmata (Diptera: Piophilidae) is reported for the first time from a forensic case in Spain, enhancing the interest of its presence in corpses to estimate the PMI. The procedure followed for each scientific specialist is detailed and the possibilities and requirements of each discipline are discussed in detail. Taking into account that institutional interdisciplinary collaboration is not a rule in solving cases of forensic investigation in Spain, the relevance and need of such interdisciplinary collaboration in solving cases of forensic investigation is emphasized.     

Ultrasonographic densitometry of the lungs at autopsy: a preliminary investigation for possible application in forensic pathology

The aim of the present study was to examine the possible application of ultrasonographic (US) densitometry of the lungs to quantitative evaluation of pulmonary edema at autopsy (n=85). A diagnostic ultrasound device LOGIQ alpha200 (GE Yokogawa Medical Systems) equipped with an LH probe (linear, 7.5 MHz) was used and each lobe of the lungs was scanned on the anterior and posterior surfaces after resection. The US density showed a correlation between the left and right lobes, and also between the anterior and posterior surface scans of each lobe. Although there was a correlation between the US density and combined lung weight in total cases, the density ranged very widely when lung weight was below about 1300 g, depending on the cause of death. The density was high in drowning, asphyxia, poisoning and delayed traumatic death, whereas it was usually low in fire death mainly due to burns, hemorrhagic shock and head injury. In the other causes of death, a considerable case-to-case difference was observed independent of the lung weight. These findings suggested a possible contribution of pulmonary edema to high US density, possibly depending on the survival time and irrespective of the blood contents (congestion or postmortem hypostasis).     

Mass spectrometry-based proteomics as a tool to identify biological matrices in forensic science

In forensic casework analysis, identification of the biological matrix and the species of a forensic trace, preferably without loss of DNA, is of major importance. The biological matrices that can be encountered in a forensic context are blood (human or non-human), saliva, semen, vaginal fluid, and to a lesser extent nasal secretions, feces, and urine. All these matrices were applied on swabs and digested with trypsin in order to obtain peptides. These peptides were injected on a mass spectrometer (ESI Q-TOF) resulting in the detection of several biomarkers that were used to build a decision tree for matrix identification. Saliva and blood were characterized by the presence of alpha-amylase 1 and hemoglobin, respectively. In vaginal fluid, cornulin, cornifin, and/or involucrin were found as biomarkers while semenogelin, prostate-specific antigen, and/or acid phosphatase were characteristic proteins for semen. Uromodulin or AMBP protein imply the presence of urine, while plunc protein is present in nasal secretions. Feces could be determined by the presence of immunoglobulins without hemoglobin. The biomarkers for the most frequently encountered biological matrices (saliva, blood, vaginal fluid, and semen) were validated in blind experiments and on real forensic samples. Additionally, by means of this proteomic approach, species identification was possible. This approach has the advantage that the analysis is performed on the first “washing” step of the chelex DNA extraction, a solution which is normally discarded, and that one single test is sufficient to determine the identity and the species of the biological matrix, while the conventional methods require cascade testing. This technique can be considered as a useful additional tool for biological matrix identification in forensic science and holds the promise of further automation.     

Methodical approach to brain hypoxia/ischemia as a fundamental problem in forensic neuropathology

A review is given summarizing different methods that have been applied to the specific forensic neuropathological question of brain hypoxia/ischemia. On the microscopic level the authors applied routine stains and immunohistochemistry (MAP2, ALZ 50, GFAP, CD68, beta-APP) for characterization of the functional activity of neurons as well as of different cell types in various brain areas. Moreover, using molecular techniques for evaluation of the mitochondrial 4977-bp deletion in correlation to hypoxia and to age brain tissue and single cell analyses are described. The demonstrated scope of methods and results give evidence of the wide spectrum of possibilities to visualize hypoxic brain injuries for determining the cause (and matter) of death and for reconstructing the time-dependent process.