Dermal lesions after post mortem petrol-exposure

The effect of post mortem contact of the skin with petrol was investigated in 18 corpses with exposure times between 10 min and 24 h. The earliest onset of skin changes was observed within 2 h of exposure. They consisted of swelling and wrinkling with detachment of the upper layers of the skin (positive Nikolski's sign). Histologically the lesions appeared as non-vital acantholyses located in the prickle-cell layer with formation of intra-epidermal bullae. An influence of age and sex could be excluded, the earlier onset of lesions at 22 degrees C than at 4 degrees C was not statistically significant. These findings prove that post mortem petrol exposure may lead to dermal lesions.     

Estimation of the post mortem period by multiple-site temperature measurements and the use of a new algorithm

The estimation of the post mortem period, in cases where death occurred under suspicious circumstances, is usually attempted using temperature measurements taken at a single body site. Early investigations of the validity of such an approach use the abdominal skin surface, the axilla and the rectum as measurement sites (B.H. Knight, Forensic Sci. Int., 36 (1987) 47-55). However, it has recently become more common to use the rectum alone, though the ear and the nasal passages have also been utilized. Whatever site is employed, the estimates are frequently found to be inaccurate. There are several fundamental reasons for these inaccuracies, the most prominent being the unknown variation in the ambient temperature between the time of death and the commencement of measurements, and the unknown body temperature at the time of death. This paper proposes a method of overcoming the above difficulties by taking a series of measurements concurrently at a number of body sites, a technique used by several previous workers (B.H. Knight, Forensic Sci. Int., 36 (1987) 47-55). Initial investigations have shown that an improved estimation of post mortem period is obtainable by the application of a suitable decision-making algorithm.     

Aspiration of gastric contents in hanging with typical position of the strangulation cord and free suspension]

Among 193 cases of hanging from the years 1978 to 1991 examined in the institute of Forensic Medicine of the Freie Universit?t Berlin 8 cases with an aspiration of stomach contents had been reported. Herefrom 3 cases were hanging in a "typical" position (suspension point at the back of the head, free suspension of the hanging body) and did not undergo resuscitation. By free suspension of the hanging body the observed massive aspiration of gastric contents only can be explained by an at least partly open connecting passage between the laryngeal entry and the entrance of the oesophagus. The post mortem flowing in of stomach contents as well as a post mortem gastro-oesophageal peristalsis seem not to be able for explicating the findings. Differences in important parameters (e.g. gastric contents, alcoholization) to the cases of hanging without aspiration were not found. Even by free suspension of the body, running noose and point of suspension in the back of the neck sometimes the connection between larynx and oesophagus may stay open, especially when by emesis a high pressure is produced by the stomach.     

Postmortem exsiccation of the fingertips--results of a systematic quantitative and qualitative experimental study

To date there have been no results published on qualitative and quantitative time-related changes with regard to desiccation of human fingertips post mortem. The fingertips of 52 hands from 36 corpses were qualitatively examined soon after death (2-6 h) to 120 h post mortem. The quantitative investigations were confined to the tips of the middle fingers. The width of three adjoining ridges of the skin was measured in four defined areas of the middle fingertips, and photographs were taken at intervals of 2, 3, 4, 5, 6, 7, 8, 12, 20, 26, 32, 44, 50, 60, 72, 84, 96 and 120 h p.m. Concerning the qualitative test results, four time-related stages were classified macroscopically and by a pocket lens (X25). Desiccation stage IV correlates to the period 72 h after death in bodies found in apartments. Besides the rough, wrinkled, and brown or black surface of the fingertips, microwrinkles of the epidermis occur on the skin ridges, which have so far not been described. The quantitative results did not show any changes in the width of the skin ridges, independent of age, sex, right or left hand.     

Comparison of ethanol concentrations in right cardiac blood, left cardiac blood and peripheral blood in a series of 30 cases

The aim of this study was to compare ethanol concentrations in right cardiac blood, left cardiac blood and peripheral blood. Samples were taken from a series of 30 medicolegal autopsies. Ethanol was measured by headspace GC-FID. In each case, the degree of putrefaction, chest or abdominal injury, and/or regurgitation of gastric contents into the airways were noted. Our results show that there exists in certain cases a marked increase in ethanol concentration in left cardiac blood compared with right cardiac blood and peripheral blood. In these cases, we observed (i) a high concentration of ethanol in the gastric contents and (ii) regurgitation of gastric contents into the airways. The authors discuss the post-mortem redistribution mechanisms which could explain these results and stress the value of sampling right cardiac blood at autopsy.     

Finger prints on human skin--results of a general applications-oriented series

Numerous methods have been described for making dactyloscopic traces visible on human skin, but these have never become routine--last but not least because they are too complicated and time-consuming to perform. The purpose of the present investigation was to find out to what extent fingerprints on the skin of deceased persons can be made visible with the help of conventional methods like iodine fuming or brushing with Magna-Brush and can be preserved with gelatine film or moulding material. Of the total number of 486 experimental fingerprints the dermal ridges could be made visible in 150 prints. The best findings were obtained when the trace had been applied several hours post mortem. On the skin of the extremities better results could be achieved than on the trunk or the neck. Dactyloscopic tracing on the skin of bodies in homicide cases should be taken into consideration especially if there is evidence that the perpetrator touched the victim after his/her death (e.g. if the body was transported).     

Investigations to determine the time of death, late post mortem, by means of electrophoresis of inner organs (author's transl)

In CAF-electrophoresis, extracts of cardiac muscle and of kidney tissue, after storage at 4 degrees C, show a roughly linear increase of the equivalent to the Albumin fraction. This increase depends on the time elapsed and is explained by the relatively high stability of this fraction compared to organ proteins, which appear in the globulin region. Thus, a sort of internal standard exists and can be used as a parameter for the determination of the post mortem period. Hepatic tissue is less suitable for this kind of investigations as the relation of the post mortem period and the values of the relative concentration of the fraction do not show the linearity found in cardiac muscle and kidney tissue. Splenic tissue shows no distinct trend and the findings are of little value. The present investigations were arranged in such a way that taking the order of magnitude for the equivalent of the Albumin fraction as a guideline led to a determination of the maximum post mortem period, i.e., the maximum period of time the body lay after the hour of death. The tables of this paper show the figures for the individual organs.     

Homicide by asphyxia--yes or no? On the use of muscle histology

In two cases of death autopsy revealed large hemorrhages in the muscles of the neck, which lead to the conclusion of a murder by strangulation, e.g. with a soft tool. Histologic examination of the injured muscles didn't show any sign of vital reaction, which means, that they had developed post mortem. There was no reason for further suspicion of a violent crime. Later it became obvious, that neck lesions resulted from inadequate recovery and transport of the corpses. "Vital" type of muscular alteration is characterized by segmental or disk-like fragmentation of muscle fibres, loss of sarcoplasmatic cross-striation and appearance of pathologic longitudinal fibrillar structures. These signs are missing in case of a postmortal injury, whereas the cross striation is intact. The slides should be stained with PTAH. With these two cases we would like to demonstrate the importance of histologic examination of injured muscles, when question for intravital or postmortal injury rises.     

Comparison of the clinical and post mortem diagnoses of the causes of death

The fast moving progress in medical technology causes someone to ask if the progress is not only in diagnostic abilities but also in diagnostic precision. Despite the improved quality of diagnostic technology, the frequency of misdiagnosis has not decreased appreciably. The goal of autopsy is not only to uncover clinicians mistakes or judge them but rather to instruct clinicians to learn by their own mistakes.We reviewed the autopsy records from the Archive of the Institute of Forensic Medicine in Ljubljana of 1792 deceased persons in 1997 and 1998 and compared the clinical and post mortem diagnoses. We eliminated from study all autopsies performed on deceased persons not admitted to the Clinical Medical Centre. From the remaining 911 autopsy reports we compared the post mortem diagnoses with the clinical diagnoses. We classified findings into five groups according to the level of agreement between the clinical and the post mortem diagnoses. Group 1 included cases of complete agreement between clinical and post mortem diagnoses. Group 2 cases of disagreement about the basic illness, group 3 cases of partial disagreement about the direct causes of death, group 4 cases of total disagreement between the clinical diagnosis and the post mortem, named, also misdiagnosis and group 5 clinical diagnosis which could not be calssified.The diagnoses were in total agreement in 49.30% of cases, in partial agreement (disagreement about direct causes of death) in 20.68% and in disagreement about the basic illness in 6.87%. The diagnoses were in total disagreement in 9.87%. 13.30% of cases were not possible to classify owing to incomplete death certificates or reports of the causes of death.     

Pathological spectrum of the lung in cases of violent death: Part II. Clinicopathologic correlation

The correlation between the type of pathological lesion of the lung and the circumstances which encompass their evolution in 66 cases of violent death have been examined. Pulmonary lesions have been classified into four groups. 1. Inflammatory alveolar lesions without a diffuse interstitial involvement (IAL) which result from direct aggressions in subjects of advanced age. 2. Inflammatory alveolar lesions with a diffuse interstitial affectation (IALW) which are more frequent in younger subjects having a higher defense capacity and with severe lesions requiring admission to an intensive care unit. 3. Edemohemorrhagic lesions (EHL) appearing as a precocious lesion at any age. 4. Unspecific chronic lesions (UCL) previous to the aggression and without any relationship to death. The most obvious feature noted was the frequent occurrence of certain types of acute pulmonary lesions indicative of the rapid and extensive capacity of the lung to react to a lesion agent even when death follows rapidly after the aggression. The scarcity of acute interstitial lesions among the older group can be related to a diminution of biological defense activity leading to a less vigorous response; on the contrary, diffuse lesions of the wall seem to be related to an excess of defense mechanisms, determined more by age, severity of lesion, and type of medical assistance received than by a specific type of aggression.     

Validation study of endogenous reference genes for normalization of quantitative real time PCR data in post mortem skin tissue

Gene expression profiling may provide insights into the molecular mechanisms underlying wound skin repair contributing to applications in the field of post mortem forensic wound age estimation. Quantitative real-time PCR (qPCR) is the most sensitive technique for gene expression studies but represents a complex procedure with several requirements for accurate data analysis. One of the major pre-requisites is the selection and validation of appropriate endogenous control genes for normalization in a given set of samples. In this study, the gene expression stabilities of ten endogenous controls ACTß, ß2M, PPIA, GAPDH, HPRT1, PGK1, SDHA, TBP, UBC, and YWHAZ were evaluated in two sets of samples: post mortem human wounded and unwounded skin tissue aimed for subsequent wound age estimation studies. The most stable genes were determined by calculating a gene expression normalization factor for each sample based on the geometric mean of the ten selected genes using the reference gene validation software, geNorm. In uninjured skin, the most stable endogenous controls were YWAZ, with the highest stability, followed by PGK1 and GAPDH. In the wounded samples, GAPDH was the most stable gene followed by PGK1, ACTß and HPRT1. Both groups revealed some differences relative to reference gene expression stabilities, nevertheless, PGK1 and GAPDH could serve as two possible common reference genes for qPCR data normalization as both were identified as stable genes in wounded and unwounded skin tissues. The differences of expression stabilities of the reference genes identified in both groups support the need for accurate normalization of gene-expression levels previous to qPCR studies.     

Death following atypical compression of the neck

The authors present 3 cases of asphyxia caused by atypical compression of the neck by the metal bed bars fitted at the sides of the bed to prevent falling out. These occurred in 3 elderly women living in nursing homes, confined to bed by severe neuropsychiatric disturbances. In all 3 cases, the minor nature of the skin lesions and absence of blood infiltrations in the anatomic structures of the neck had made it difficult to diagnose the cause of death. Inspection of the rest homes, together with the autopsy findings (acute pulmonary emphysema, conjunctival petechiae, and dark, fluid blood), enabled identification of asphyxia as the cause of death and its causal agent as the bed bars.     

Experimental studies of the development of linear electric current marks

By means of reconstructing electric current pathways electrophysical conditions were explored causing electrocution death in the bathtub, according to many authors quite often indicated by linear electric lesions. In our experimental settings we observed appearance of circumscribed linear marks of pallor similar to electric lesions in the region of postmortem lividity of corpses at the same level as bathtub water. None of typical histological indicators could be seen in skin samples. So no evidence was given for electric burns even under conditions of high density and extended duration of current. Similar linear marks and equivalent histological results were found when corpses were put into the bathtub filled with cold water without any experimental electric contact. CONCLUSIONS: Linear marks of pallor may occur at water level even without any electric contact to corpse or water neither bathtub. IMPLICATIONS: According to specific conditions mentioned above linear so called electric lesions at water level do not indicate electric current yet lethal electric damage.     

A preliminary investigation on the distribution of cannabinoids in man

An LC/MS/MS procedure to determine THC along with its major metabolites 11-OH-THC, THC-COOH and its glucuronide as well as the cannabinoids CBD and CBN was applied to 5 post mortem cases to study their distribution into some less commonly studied matrices. Analytes were determined in fluids and tissue homogenates following protein precipitation and liquid-liquid extraction. Gall bladder fluid exhibited maximum concentrations of all analytes except THC, which was detectable in high concentrations in muscle tissue along with CBD. THC was also present in lung specimens, whereas its concentration in liver samples was low or not detectable at all. Liver und kidney specimens contained appreciable amounts of THC-COOglu. Findings from bile support extensive enterohepatic recirculation of the glucuronide. Muscle tissue seems an interesting specimen to detect multiple cannabis use, and brain may serve as an alternative specimen for blood; nevertheless, the present findings should be substantiated by further investigations.     

Ultrastructural pathology of mechanical skeletal muscle damage

In continuation of previous light microscope investigations the question has been raised whether the criteria determined for vital muscle damage using light microscopy, could be verified and perhaps extended for the ultrastructural region. In addition to existing human pathological material taken early post mortem, muscle tissue obtained from animal experiments was also examined. The evaluation concentrated on the muscle cells, the cell organelles and the contractile apparatus. An evaluation of semi-thin-sections was carried out in parallel. The following reaction patterns could be defined as vital reactions: hypercontraction bands, zones of rupture in narrow topological relationship to organelle changes, microstructure changes with disintegration of the fibre structure, subsarcolemmic and interfibrillary oedema, decomposition of the sarcolemma. The earliest vital reactions were detectable after only a few minutes survival time. The comparison between the results of animal experiments and human pathology and the application of the results to forensic pathology will be discussed.     

A forensic international market survey of condom lubricants and personal hygiene products using ATR-FTIR coupled to chemometrics

Condom residues may be encountered in forensic investigations as traces in sexual assault or rape cases. Casework studies have shown the value of distinguishing condom residues from other types of personal products used by women. However, up to now, there has been no investigation of their chemical variability within an international context. This work employed attenuated total reflectance Fourier transform infrared spectroscopy with chemometrics to provide objective characterisation of condom lubricants and personal hygiene products from the international market. 166 samples were obtained covering five major classes of products likely to be used by women. Principal component analysis distinguished most major classes based on their spectral profiles, with subsequent support vector machine models yielding discrimination accuracies over 90%. A two-step approach was subsequently developed and enabled both classification and a discrimination accuracy of 100%. This could provide greater confidence in chemical discrimination of residues from these products when conducting investigations and help assess the origin of the chemical profile obtained. Further testing using three validation sets produced an identification accuracy of 100% for generic classes, which may allow investigative leads to be more readily obtained from recovered evidence.     

Histopathological differentiation of skin lesions caused by electrocution, flame burns and abrasion

The aim of this study was to reveal histopathological features for differential diagnosis of skin lesions caused by electrocution, flames and abrasions. Based on the causes of the lesions, cases were assigned into three groups. Group 1 included 30 deaths from electric shock. Group 2 included 30 individuals with flame burns who died in the fires. Group 3 included 30 deaths from traffic accidents, from which the individuals had abrasions. Data from the crime scene investigations and macroscopic and microscopic findings from the autopsies allowed determination of the cause of death in all cases. The features of the lesions examined under the light microscope were intraepidermal separation, subepidermal (dermoepidermal) separation, coagulation necrosis in the epidermis, nuclear elongation in the epidermis, dark-staining epidermal nucleus, depth of homogenization in the dermis, and nuclear elongation in the epithelium of hair follicles. A significantly high rate of electrical lesions had intraepidermal separation. The rate of subepidermal separation was slightly more significant in flame burns. A significantly higher rate of electrical lesions had both intraepidermal and subepidermal separation. The rate of coagulation necrosis in the epidermis was significantly the highest in electrical lesions. Although the severity of nuclear elongation was the most significant in electrical lesions, varying degrees of nuclear elongation in the epidermis were present in all three groups. Dark staining of the epidermal nuclei was present in all lesions except for one electrical lesion, though the severity of staining was significant in the abrasion group. The depth of homogenization was slightly more significant in the abrasion group. The rate of nuclear elongation in the epithelium of the hair follicles was significantly lower in the abrasion group. The results of this study revealed that certain morphological changes determined under a light microscope could help the differential diagnoses of electrical lesions, flame burns and abrasions.     

Locard's Principle of Exchange,Dental Examination and Fragments of Skin

The transfer of materials between victim and perpetrator was first reported by Locard in the nineteenth century. While in recent years DNA testing has been very successful in matching biological material from crime scenes to perpetrators, the following cases demonstrate that other more time‐honored methods remain useful. Two cases of lethal assault are reported where the victims had bitten their assailants resulting in fragments of the perpetrators’ skin being wedged between their teeth which were discovered during post mortem oral examinations. As the fragments were able to be matched to injuries in the perpetrators, identification was established prior to confirmatory DNA testing. In case 1 a criminal conviction for manslaughter resulted, and in case 2 the identity of the assailant was confirmed. Examination of a properly exposed and illuminated oral cavity may provide useful evidence in assault cases. These cases represent an unusual dental variant of Locard's principle.     

Chemical composition of fingerprints for gender determination

This work investigates the chemical nature of fingerprints to ascertain whether differences in chemical composition or the existence of chemical markers can be used to determine personal traits, such as age, gender, and personal habits. This type of information could be useful for reducing the pool of potential suspects in criminal investigations when latent fingerprints are unsuitable for comparison by traditional methods. Fingertip residue that has been deposited onto a bead was extracted with a solvent such as chloroform. Samples were analyzed by gas chromatography/mass spectrometry (GC/MS). The chemical components identified include fatty acids, long chain fatty acid esters, cholesterol and squalene. The area ratios of ten selected components relative to squalene were calculated for a small preliminary experiment that showed a slight gender difference for three of these components. However, when the experiment was repeated with a larger, statistically designed experiment no significant differences between genders were detected for any of the component ratios. The multivariate Hotelling's T2 test that tested all ten-component ratios simultaneously also showed no gender differences at the 5% significance level.