Tool In Forensic Medicine Research Articles

Identification of gunshot entry wounds using hyperdense rim sign on post-mortem computed tomography.

Post-mortem computed tomography (PMCT) is an increasingly utilized tool in forensic medicine for evaluating head gunshot injuries. Vault bevelling sign, when present, provides information regarding entry and exit wounds; when absent, identifying wound type on PMCT remains challenging. A cutaneous hyperdense ring, described in an animal study by Junno et al. (2022), may be indicative of contact shots. We hypothesized that it could also be observed in human gunshot injuries. Our study evaluates the reliability of the cutaneous hyperdense rim sign for identifying entry gunshot wounds in PMCT. After excluding complex and mucosal wounds, two operators retrospectively evaluated 64 gunshot wounds (30 entry and 34 exit wounds) in 34 head PMCT cases (2018-2022). Gold standard for wound type determination was the autopsy report. The hyperdense rim sign was defined as at least two-thirds of a continuous cutaneous hyperdense circle on a multiplanar reconstruction of cutaneous tissue tangent to the wound. The hyperdense rim sign demonstrated a specificity of 97% (95% CI: 85-100%) and a sensitivity of 63% (95% CI: 44-80%) for identifying entry wounds. Moreover, in 16 external examination reports where the presence of powder residues or bullet wipe at entry wound was explicitly mentioned, a positive association was observed between hyperdense rim sign and the presence of these elements (p = 0.018). These findings suggest that the hyperdense rim sign, when present, may be a valuable tool for entry wound determination in gunshot injuries, interpreted in conjunction with other CT and autopsy features.

Anthropometric Study of Nasal Indices among the Akan People in the Assin Districts of Central Region, Ghana

Introduction: Nasal index (NI) may establish racial and ethnic identity and serves as a useful tool in forensic medicine and reconstructive surgery. Previous studies on nasal indices in many races and ethnicities serve as baseline and reference points for forensic and surgical purposes in those populations. However, there is scanty or no data on NI in Ghana including the Akan ethnicity. The study was conducted to provide baseline data on NI among the Akan people in the Assin Districts of the central region of Ghana. Materials and Methods: Four hundred adults between the ages of 20 and 58 years were used. Nasal height (NH) and nasal width (NW) were measured using Vernier caliper. NI computation and statistical analyses such as z-test and Pearson correlation were performed. Results: Mean NI of 91.32 ± 8.66 and 89.39 ± 10.16 were recorded in males and females, respectively, indicating that the predominant nose type in the study population is platyrrhine. There was a strong positive correlation between NH and NW, but there was no sexual dimorphism in NI among the Akan population. Discussion and Conclusion: This study provides a baseline data on NI anthropometry of the Akan people of the Assin Districts and will be a reference point for nasal anthropometry for clinical practice, rhinoplasty, and forensic science.

Blood as an Important Tool in Forensic Medicine in Sub-Saharan Africa: Nigeria as a Perception

Blood is one of the most important biological tools in forensic medicine used to resolve and investigate crime-related cases because it contains useful details. It entails an analysis of various aspects of bloodstains that contribute to the clarification of some violent criminal cases. The knowledge of forensic medicine is essential to provide answers about a series of events and mechanisms of the creation of specific groups of bloodstains on the crime scene. This includes investigation towards the analysis of bloodstains. This knowledge enables the interpretation of results and makes it possible to get closer to the truth, solve particular crimes and ensure accuracy in the legal determination of criminal offences which helps in a proper penalty when making a judgment for the offender

Postmortem injury evaluation using the Forensic Injury Severity Score Template (FISST): a preliminary study.

The Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS) are important evaluation tools used in clinical practice to determine the degree of injury in patients with trauma. However, they are not suitable for forensic practice and their use in forensic applications is limited. This study aimed to present a system that can objectively and quantitatively determine the severity of postmortem injuries and that can be applied to forensic medicine. Subsequently, we applied this system to individual postmortem cases and analyzed the injuries identified during autopsy. We performed a retrospective study of 119 autopsies performed between 2018 and 2021. Data were categorized and analyzed using the Forensic Injury Severity Score Template (FISST), a scoring system developed based on the AIS and ISS. The mean FISST scores were as follows: men, 53.6; women, 46.8; 20-65years old, 55.6; older than 65years, 41.4; natural death, 13.8; unnatural death, 66.3; and all deaths, 51.8. Statistically significant differences in the FISST scores were found between natural and unnatural deaths, suicidal and accidental deaths, and trauma-related death subtypes. Injuries identified during autopsy can be objectively and quantitatively evaluated using FISST. We suggest that FISST is a useful tool in forensic medicine because it is tailor-made for injury evaluation from a postmortem perspective.

Comparative Evaluation of Nasal Index and its Role in Sexual Dimorphism in Central Indian Population: A Cross-sectional Study

Introduction: Nasal Index (NI) is a sensitive anthropometric index. It exhibits sexual difference and has become useful tool in forensic medicine and reconstructive surgery. It is an important anthropometric parameter for classification of gender of a person whose identity is not known. Aim: To determine the values of the nasal parameters such as Nasal Height (NH), Nasal Breadth (NB) and NI, clinically and radiographically for male and female and also to compare the NI and its role in sexual dimorphism. Materials and Methods: This cross-sectional study was conducted in the Department of Anatomy of a premium Medical College in Bhopal, Madhya Pradesh, India, between July 2017 and July 2019, study included total 392 subjects (196 males and 196 females), aged between 18 to 60 years. Posteroanterior (PA), Cephalogram (Ceph) was taken for all the study subjects. NH and NB were measured both clinically and radiographically. NI was then calculated as NB/NH×100. The data was analysed statistically using unpaired Student’s t-test. Results: As males and females were equally divided, major subjects belonged to the age group of 41-50 years (31.63%), followed by 51-60 years (27.04%). Radiographic findings of NH were found to be statistically higher in males (47.46±2.26 mm) while clinical findings of NH were found to be statistically higher in females (55.66±3.21 mm). Radiographic findings and clinical findings of NB were found to be statistically higher in males (33.95±2.41 mm, 37.19±2.44 mm) as compared to females (30.55±1.50 mm, 32.41±1.58 mm). Radiographic findings and clinical findings of the NI were found to be statistically higher in males (71.70±6.21, 69.94±5.87) as compared to females (67.02±5.21, 58.44±4.70). Conclusion: Nasal parameters showed significant differences between males and females in Central Indian population, suggesting sexual dimorphism and also serve as important clinical and radiographical tools useful in nasal surgeries, anthropometry and forensic medicine

Denture Labelling as an Identification Tool in Forensic Medicine: A Case Report

Denture labelling is gaining popularity in geriatric patients particularly for those staying alone or in old age home, especially the ones suffering from dementia or physical vulnerability. Various methods of denture labelling have been proposed by prosthodontists over the years. Prosthodontists are playing an important role in forensic odontology nowadays. This article highlights a method of denture identification marking wherein a patient’s photograph along with his name and emergency contact number is incorporated within the complete denture.

Estimation of Time Since Death from Rigor Mortis - An Autopsy Study in Tertiary Care Hospital of Malwa Region of Punjab state of India

Background: Postmortem interval estimation is an important tool in forensic medicine. Estimating time since death is extremely important in cases where there is doubt about the period of death. After death, many changes occur in a regular sequence and can be used to arrive at an approximate time since death. When a post-mortem is conducted, doctor conducting the post-mortem examination has to give his opinion about post-mortem interval i.e. the probable time that elapsed between death and post-mortem examination even in cases of decomposed dead bodies. While giving this opinion, we always think we should have some other dependable methods to be more accurate in answering this question. Algor mortis, Rigor mortis, and Livor mortis have been the basis for ascertaining the post-mortem interval collectively. Among them, Rigor Mortis is an important indicator of post-mortem interval. Although it is a dependable tool for estimating post-mortem interval, it is influenced by many endogenous and exogenous factors like nature of death, nature of the body, temperature, humidity etc. Time of death is almost always asked by investigating authorities to connect the crime with criminals. Determining the death time has always been a topic of keen interest amongst forensic pathologists from its inception to date. Many workers in forensic medicine have tried to investigate to determine the time of death based on post mortem findings. To date, it is still an important and fascinating criterion to ascertain the time since death. With this study, we aimed to demonstrate the intricacies of Rigor Mortis with fluctuating temperature and humidity of the local region. We planned to estimate and compare the post-mortem interval based on Rigor Mortis in different body muscles. Materials and Methods: This study was conducted in the Department of Forensic Medicine and Toxicology at G.G.S. Medical College, Faridkot after taking clearance from the institutional ethics committee. Thirty medico-legal autopsy cases were included in the study where the exact time of death was known and included only hospital deaths. The relatives of the deceased were explained the purpose and nature of the study and provided with the patient information sheet and informed consent was taken. The details of the cases were noted from the hospital bed head ticket, relative interview and the police inquest papers. The exact temperature and humidity were noted at the start of autopsy using a digital hygrometer. Results: A total of 30 cases were observed out of which males outnumbered the females by approximately 3:1. Maximum cases consisted of Roadside Accidents (43.3%) followed by poisoning, assault and hanging, in that order. The average temperatures during the study months varied from a maximum of 41.3°C (June) to a minimum of 33.7°C (July). The average humidity varied from a maximum of 62.6% (July) to a minimum of 29.3% (May). The average temperatures during the study months varied from a maximum of 41.3°C (June) and a minimum of 33.7°C (July). The average humidity during the study months varied from a maximum of 62.6 % (July) and a minimum of 29.3% (May). Fully established Rigor Mortis was observed at a minimum of 10 hours and a maximum of 29 hours in May and June.

Serial estimation of gene expression of cardiac troponin I (cTnI) and autophagy gene HMGB1 to determine postmortem interval

The estimation of accurate post mortem interval (PMI) is a crucial question in forensic medicine. Several approaches have been used to determine the PMI including physical, metabolic, autolytic, entomological, physiochemical and biochemical methods over time. For estimation of PMI, RNA degradation after death is reported to be an important tool. This study aimed to analyse the pattern of gene expression by serial estimation of cardiac specific cardiac troponin I (cTnI) gene and autophagy gene HMGB1 for determining PMI at room temperature by using housekeeping gene GAPDH. Right ventricular heart tissue weighing 10 g was collected and harvested from 17 medico-legal autopsies. The tissue was homogenized in phosphate-buffered saline (PBS) on ice. Further, homogenate of cardiac tissue was analysed by quantitative Real time polymerase chain reaction (qRtPCR) for gene amplification and gene expression of cTnI, HMGB1 gene and GAPDH, at different time intervals (0,6,12 h) at room temperature. The result revealed ∆Ct value of cTnI gene of the cardiac muscle showing almost equal degradation at equal time interval correlated with PMI within 0–12 h at room temperature, and the ∆Ct value of HMGB1 degraded to half in every subsequent 6-hour interval at room temperature. In conclusion, the estimation of PMI by analysis of serial estimation of gene expression is a decent new tool in forensic medicine. The study shows an equal degradation of cTnI gene at equal time interval and HMGB1 degrades to half at six-hour interval. Therefore, these can be useful for estimation for PMI.

Post-mortem computed tomography findings of the frozen brain

Abstract Post-mortem computed tomography (CT) is a valuable tool in forensic medicine. Determination of cause of death may require examination of a corpse found in a frozen state. However, most radiologists are unfamiliar with the post-mortem appearance of frozen organs on CT. Here we present two cases that included CT study of the frozen brain. Both bodies were naturally frozen, and autopsies showed that the cause of death was hypothermia in both instances. On post-mortem CT images, the frozen brains exhibited hypodense areas resembling infarctions, but these were not in regions dominated by blood vessels. Residual open sulci were evident, suggesting that oedema was absent. These two features are helpful when diagnosing a frozen brain on CT images.

Anthropometric Comparison of Nasal Parameters between Male and Female of Gwalior Region

Introduction: Nasal index is a sensitive anthropometric index. It also exhibits sexual differences and it has become a useful tool in Forensic Medicine and reconstructive surgery. It is an important anthropometric parameter for classifying the race and sex of an individual whose identity is unknown. Aim: The present study was undertaken to provide baseline data of the nasal ergonomics for male and female of Hindu community of Gwalior region. Material and Method: A random sample of males of 19 to 45 years age group was chosen for examination. Nasal length, nasal breadth, nasal height and nasal depth were measured with the help of Digital Vernier Caliper. Nasal index (NI) were calculated as NB/NH×100. The data was analyzed statistically using Unpaired Student t-test. Result: Our results are comparable with other studies with mean NI ± SD of 80.59±9.122 in male which was significantly higher (p<0.05) than that of females who has NI ± SD of 77.29±8.472. Except for nasal depth, the other nasal parameters shows sexual dimorphism. Conclusion: Based on the mean NI, the predominant nose type is Mesorrhine in 63.73% of male and female (Hindu community) of Gwalior region. This study provides a baseline data for people of Gwalior region which will be valuable in nasal anthropometry for clinical practice, in reconstructive surgery, rhinoplasty and in forensic science. This study should be subjected to further investigation.

An evaluation of applied biomechanics as an adjunct to systematic specific causation in forensic medicine

Biomechanical tests of post hoc probability have been proposed by prior authors as reliable tests of causation in forensic settings. Biomechanical assessment of injury kinetics and kinematics is a potentially important tool in forensic medicine, but there is also the potential for misapplication. The most reliable application is when biomechanical analysis is used to explain injury mechanisms, such as how an injury may have occurred. When a biomechanical analysis is used as a means of determining whether, rather than how an injury has resulted from a traumatic exposure, then a lack of reliability of the methodology limits its application in forensic medicine. Herein, we describe a systematic assessment of causation by adapting established general causation principles to specific causation scenarios, and how biomechanical analysis of injury mechanics is properly used to augment such an approach in conjunction with the principles of forensic epidemiology. An example calculation of relative risk associated with cervical spine injury is provided as a representative probabilistic metric for assessing causation. The statistical benefits and limitations of biomechanical analysis are discussed as an adjunct to forensic medicine.

Capillary electrophoresis, a new diagnostic tool

Capillary electrophoresis (CE) may replace many conventional clinical laboratory methods, such as electrophoresis, Southern blotting, sequencing and HPLC (High-performance liquid chromatography). It is an ideal technique due to analytical speed, the possibility of handling great amount of samples, its capacity to separate small molecules according to their size, charge, hydrophobic and stereo-specificity its good reproducibility the use of small amounts of sample and reagents, its low costs and easy handling. The diagnosis of hereditary diseases or the predisposition to polygenic diseases related to specific mutations or polymorphisms can be carried out with this method. In clinical laboratories, this technique is being used for the analysis of several substrates present in urine or serum and for the diagnosis of some infectious agents. It is also a firsthand tool in forensic medicine for human identification and anthropology.

La electroforesis capilar como una nueva estrategia en la medicina y el diagnóstico clínico

Capillary electrophoresis (CE) may replace many conventional clinical laboratory methods, such as electrophoresis, Southern blotting, sequencing and HPLC (High-performance liquid chromatography). It is an ideal technique due to analytical speed, the possibility of handling great amount of samples, its capacity to separate small molecules according to their size, charge, hydrophobic and stereo-specificity its good reproducibility the use of small amounts of sample and reagents, its low costs and easy handling. The diagnosis of hereditary diseases or the predisposition to polygenic diseases related to specific mutations or polymorphisms can be carried out with this method. In clinical laboratories, this technique is being used for the analysis of several substrates present in urine or serum and for the diagnosis of some infectious agents. It is also a firsthand tool in forensic medicine for human identification and anthropology.

Analysis of microsatellite markers D18S70 and d20S116 in DNA isolated from dentin: Use in forensic medicine

Short tandem repeats and more specifically microsatellites represent a powerful tool in forensic medicine. In the past years, they have been extensively used in human identification and paternity testing. The aim of the present study was to analyze two microsatellite markers in the Serbian population, i.e. to determine the number of alleles and the relevant forensic parameters. DNA was isolated from teeth samples using standard proteinase K digestion and phenol/chloroform alcohol extraction. PCR products were analyzed on polyacrilamide gels and visualized by AgNO3 staining. Forensic parameters were calculated using the Cervus software. The loci D18S70 and D20S116 were analyzed on a sample of 70 unrelated, healthy adult individuals from Serbia. The number of alleles was determined and Hardy Weinberg equilibrium was confirmed for both loci. D18S70 and D20S116 demonstrated 6 and 8 alleles, respectively. The power of discrimination (PD) and the power of exclusion (PE) for the tested STR loci, D18S70 and D20S116 were 0.92 (PD), 0.41 (PE) and 0.95 (PD), 0.480 (PE), respectively. According to the presented data, D18S70 and D20S116 are most informative markers. Based on allelic frequencies and statistical parameters for forensic testing, it may be suggested that these two microsatellites represent useful markers for individual identification and parentage analysis in the Serbian population.

Capillary electrophoresis: a new tool in forensic medicine and science.

Capillary electrophoresis: a new tool in forensic medicine and science.

Multivariate analysis (‘Forensiometrics’) – a new tool in forensic medicine. Differentiation between firearm-related homicides and suicides

A forensiometric model to discriminate between homicidal and suicidal firearm-fatalities is presented. It is based on a survey of all 45 homicidal and 251 suicidal firearm-fatalities that were examined at the Department of Forensic Medicine in Stockholm, Sweden during the period 1983–92. The model used 15 variables to describe 19.8% of the variation in the data and its goodness of prediction, Q 2 , was 0.742. The variables ranked in falling order of covariation with homicide (i.e. correlation with or importance in the prediction of homicide) were: presence of other injuries than firearm-wounds, entrance wound in the front part of the chest except precordium, bullet path through clothes, entrance wound in upper extremity, female victim, entrance wound in abdomen, entrance wound in head except temples, central forehead and mouth, and entrance wound in back. The variables most correlated to suicide were: used firearm found close to victim’s body, reported suicidal ideation, victim’s age, presence of contact wound(s), male victim, presence of farewell letter and entrance wound in mouth. The model was thereafter validated on a test-set of 18 homicides and 84 suicides during 1993–95. All suicides and 16 homicides were classified by the model in agreement with the previous police and forensic medical examinations. Thus, the model’s sensitivity to classify homicides is estimated to be 89% and its specificity 100%.

Multivariate analysis (‘Forensiometrics’) – a new tool in forensic medicine: Findings on the victim of sharp-force homicide can predict the inter-relationship with the perpetrator

A multivariate ‘forensiometric’ technique (PLS-DA) was used to create a model to predict the relationship between homicide victim and perpetrator on a five-level scale: strangers, acquaintances, drinking companions, relatives and spouses. The model is based on findings on the victim and at the venue, and uses the following ten variables as ‘predictors’, listed in falling order of covariation with instances of close relationship between victim and perpetrator: Victim found in home, female victim, a single sharp injury, injuries to the upper extremity, superficial sharp injuries to the chest (‘scratches’), ten or more sharp injuries, presence of defence injuries, total number of sharp injuries, male victim, and victim found outdoors. The model was based on 87 sharp-force homicides (the model-set) and was validated on another set of 43 sharp-force homicides (the test-set). In this test-set validation, 17 of 39 cases (44%) were correctly predicted according to the results of earlier combined forensic and police investigations, and a prediction one step away from the correct level was given in another 17 cases. These results were significantly better than would have been obtained by chance.

Multivariate analysis (`Forensiometrics')—A new tool in forensic medicine: Differentiation between sharp force homicide and suicide

Multivariate projective statistical methods (PCA, PLS-DA) and logistic regression analysis were used to create models to make predictions regarding whether a certain fatality shows similarities to homicide or suicide. The `model set' consisted of 174 deaths due to sharp force injuries that in previous medicolegal investigation had been judged as homicides and 105 as suicides. The models were then validated on a new set of 40 homicides and 27 suicides that had not been used to create the models (test set validation). The model based on the PLS-DA technique had regarding its ability to identify homicides a sensitivity of 40/40=100% and a specificity of 25/27=93%. The model's predictions agreed with previously performed medicolegal investigations except in two suicides which according to the model were likely to be homicides. The reliability of this model was somewhat better than predictions achieved by means of logistic regression analysis, where six otherwise proven homicides were wrongly classified as suicides and two actual suicides were misclassified as homicides. The technique not only identifies variables but also ranks their importance. Ranked according to falling positive correlation (falling `importance' of a finding) to the dependent variable `death caused by homicide', the predictors were: Injuries to clothing, blood alcohol level, presence of defence injuries, injuries due to other type of violence than sharp force, chest stabs with vertical axis of the entrance wound, sharp force injuries to the upper extremity (except wrist and crook of the arm), sharp force injuries to the head and back. Ranked in increasing positive correlation to `death caused by suicide' were the predictors: sharp force injuries to the crook of the arm, venue being the victim's home, presence of farewell letter, victim's age, sharp force injuries to the wrist, known suicidal ideation and presence of tentative injuries.

Screening and identification of drugs in human hair by high-performance liquid chromatography—photodiode-array UV detection and gas chromatography—mass spectrometry after solid-phase extraction a powerful tool in forensic medicine

A method is described to screen for a wide range of pharmaceuticals in human hair, 75 mg of powdered hair are incubated (12 h at + 56°C) in 2 ml of distilled water (acidic compounds) or 0.1 M hydrochloric acid (neutral and basic compounds). A twin solid-phase extraction on C 18 cartridges is used for the sample clean-up procedure. Acidic drugs are fixed at pH 2 and eluted with 1% ammoniacal methanol while neutral and basic drugs are retained on the column at pH 8.6 and eluted with methanol containing 0.5% acetic acid. The internal standard (I.S.) for the acidic extraction was bupivacaine while the I.S. for the basic extraction was prazepam. The separation of the drugs was performed using both the liquid and the gas chromatographic techniques whereas identification was achieved using photodiode array and mass spectrometric detection, respectively. The liquid chromatographic system gives an elution of the drugs following a multi step gradient from a Symmetry C 8 (Waters) 5 μm column (250×4.6 mm I.D.) at +30°C with acetonitrile-phosphate buffer (pH 3.8). Identification is achieved using the reference data (retention times and spectra) of 675 pharmaceuticals, toxicants and drugs of abuse stored in a personal library. The present method has been applied during 6 months in our laboratory. By establishing a victim's drug use history, it is a very powerful tool in forensic medicine. We illustrate the method with some real cases of police crime investigation.

Use of the Gadd severity index in forensic medicine: a case study

The application of the Gadd severity index in the case of a fatal fall of a child is reported. Two important factors affecting the calculations involve the deceleration upon impact and the weighting factor applied to various injury scenarios. The Gadd severity index could be a useful tool in forensic medicine, but care is needed in its implementation.