Visualizing old biological traces on different materials without using chemicals.

During the investigative process that typically follows a criminal act, it may prove necessary to work with and analyze evidence that is not recent but old. This could become necessary, for example, when a crime is discovered some time after it was committed or when a cold case is reopened. Due to this need, the present study focused on the detection and visualization of 2-year-old biological traces. To do so, an alternative light source and different filters were used. The optical behavior of 2-year-old samples of blood, semen, urine, saliva, and sweat located on 19 different materials was documented, analyzed, and compared with the optical behavior of the same samples when they were recent [1].

Bullet fragmentation preceding a contour shot: case study and experimental simulation.

In medico-legal literature, only a small number of publications deal with lethal injuries caused by shots with modified guns. This might lead to the conclusion that such cases are extremely rare. However, there are cases again and yet again. During the investigation process, the modified gun is of particular importance since it can show an unusual ballistic behaviour. The present paper reports on a suicide of a 60-year-old man, committed with a modified revolver and a lead bullet. The man had a single gunshot wound with entrance at the right temporal bone. Autopsy revealed that the bullet had fragmented into two major parts. The smaller one stood outside the cranial cavity and pushed its way alongside between the cranial bone and scalp to its end position in the left temporal area. The bigger part entered the cranial cavity and ended in the left parietal lobe. In shots on ballistic soap and on a head-model, the ballistics of the weapon and lead bullet were characterized. The angle necessary for bullet fragmentation was determined by shots on ballistic soap and turned out to be 55°-60° at a velocity of around 200 m/s. This knowledge was transferred to contact shots on a head-model consisting of a layered polyurethane sphere filled with 10 % ballistic gelatine and covered with a skin-like cap almost all around. The resulting injury pattern corresponded to the one of the suicide person. The bigger bullet part entered the skull while the smaller part pushed its way alongside between skin and skull causing an outer contour shot. Furthermore, the revolver was documented firing off two bullets by one trigger pull-a phenomenon of importance for forensic casework the authors have not found reported in forensic literature.

Estimating the postmortem interval of human skeletal remains by analyzing their optical behavior.

The aim of this study was to figure out a new practically applicable method to distinguish between historical and recent human skeletal remains. Therefore, the optical behavior of bone cross sections was investigated using the combination of two methods: a modification of an already established test (UV-induced fluorescence) and a new method (490 nm-induced fluorescence). We evaluated the areal extent of fluorescence of 30 bone cross sections with known postmortem interval (PMI) using ultraviolet light and 490 nm light. For analysis, the areal extend of fluorescent surface was determined using photos of the samples and an image editing software. The results prove that there is a correlation between PMI and the areal extent of fluorescent surface in both tests. Furthermore, the combination of both methods is a good indicator to distinguish within the forensic relevant post mortem interval between PMI < 30 years and PMI > 30 years.

Reconstruction of crimes by infrared photography.

Whenever blunt or sharp forces are used in a crime, analysis of bloodstain pattern distribution may provide important information for the reconstruction of happenings. Thereby, attention should be paid to both the crime scene and the clothes of everyone involved in the crime. On dark textiles, though, it is difficult or even impossible for the human eye to detect bloodstains because of the low contrast to the background. However, in the near infrared wavelength range, contrast is considerably higher. Many textiles reflect light beyond a wavelength of 830 nm and thus appear light-colored, whereas blood absorbs the light and appears dark. In our studies, a D7000 NIKON reflex camera modified for infrared photography produced high-resolution photographs visualizing even very small spatter stains on dark textiles. The equipment can be used at any crime scene or lab and provides immediately available and interpretable images. Thus, important findings can be obtained at an early stage of police investigations, as two examples (homicide and attempted homicide) illustrate.

Searching for biological traces on different materials using a forensic light source and infrared photography.

Because biological traces often play an important role in the investigation process of criminal acts, their detection is essential. As they are not always visible to the human eye, tools like a forensic light source or infrared photography can be used. The intention of the study presented was to give advice how to visualize biological traces best. Which wavelengths and/or filters give the best results for different traces on different fabrics of different colors? Therefore, blood (undiluted and diluted), semen, urine, saliva, and perspiration have been examined on 29 different materials.

Complex suicide by ethanol intoxication and inhalation of fire fumes in an old lady: interdisciplinary elucidation including post-mortem analysis of congener alcohols.

An 88-year-old woman committed suicide by drinking a toxic amount of highly concentrated alcohol and setting two rooms of her flat on fire. As there was not enough oxygen, the fire went out, however. At autopsy, no thermal lesions were found on the body, but soot depositions in the airways and a COHb value of 14% pointed to the inhalation of fire fumes. The ethanol concentration in femoral blood was 6.62 per mille. The gastric mucosa was fixed by the ingested alcohol and showed hardly any autolytic changes despite a post-mortem interval of five days. Congener analysis of the gastric contents and the femoral blood indicated the uptake of a fruit distillate or its foreshot.

Petechial bleedings in sudden infant death.

The autopsy reports of 484 cases of deceased infants (201 females, 283 males) were analysed retrospectively for the existence of external and internal petechial bleedings (PET). The cases were divided into five groups on the basis of the cause of death (sudden infant death syndrome, sepsis, airway infections, asphyxia and trauma). Internal PET (pleural, pericardial, epicardial, thymic and peritoneal) were observed in each group with a lower prevalence in cases of trauma. The highest prevalence of external (cutaneous and conjunctival) PET was detected in cases of asphyxia (38% and 31%, respectively). However, even if with low prevalence, such bleedings were detected in every group. Factors like sex, age, cardiopulmonary resuscitation and its duration did not influence the presence of PET. The detection of external PET at autopsy is a suspicious finding that suggests asphyxia. Because of the possible natural origin of these bleedings, the medicolegal investigation has to be as complete as possible and has to include histology as mandatory.

Suicidal poisoning with mercaptodimethur-morphological findings and toxicological analysis.

In the western countries, the number of fatal intoxications with plant protecting agents has decreased to some extent due to laws restricting the use of highly toxic pesticides like halogenated hydrocarbons. Nevertheless, in consideration of the easy availability of most plant protectants, the small fraction of such fatalities among suicides and intoxications is astonishing. An 80-year-old woman died of an intoxication with methiocarb (mercaptodimethur), a carbamate type pesticide and as such a reversible inhibitor of the acetylcholinesterase. The case is presented because it is the first explicit report on a fatal poisoning of a human with methiocarb. The methiocarb concentrations detected were 6,100 microg/g in stomach content, 4.0 microg/ml in heart blood, 11 microg/g in kidney, 1.9 microg/ml in urine, 25 microg/g in liver, 2 microg/g in bile and 2.5 microg/g in brain tissue.

Expression of heat-shock protein 70 (Hsp70) in the respiratory tract and lungs of fire victims.

Immunohistochemical investigation of the respiratory tract and lungs of 63 fire victims revealed a statistically significant enhanced expression of heat-shock protein 70 (Hsp70) in the epiglottis, the trachea, and the main and the peripheral bronchi compared with a control group. In the fire victims, a strong expression of Hsp70 was discernible not only particularly in the vessels but also in seromucous secretory cells, ciliated epithelial cells, smooth muscle cells, and alveolar cells. The results suggest a vital or supravital reaction due to the inhalation of hot fire fumes.

Unnatural causes of sudden unexpected deaths initially thought to be sudden infant death syndrome.

The aim of this clinicopathological study was to determine the frequency of infant deaths due to unnatural causes among cases of sudden and unexpected infant death. Nine institutes of legal medicine in Germany that took part in the German study on Sudden Infant Death Syndrome (GeSID), representing 35% of the German territory, investigated in a 3-year period (from 1998 to 2001) 339 cases of infant death that were not expected to be due to unnatural causes from the first external examination. All cases were investigated by complete, standardised, post-mortem examination including death scene investigation, autopsy, histology, toxicology and neuropathology. The frequency of unnatural deaths was 5.0% (n=17). The causes of death were head injury (n=7), suffocation (n=5), poisoning (n=2), neglect (n=2) and septicaemia due to aspiration of a foreign body (n=1). Two deaths were unsuspected accidents and 12 were due to infanticide. In 3 cases, it was not possible to differentiate between accidental death and infanticide. A complete postmortem examination including an analysis of the clinical history, death scene investigation, autopsy, histology, toxicology, and neuropathology is mandatory to differentiate sudden and unexpected deaths due to natural causes (e.g. SIDS) and cases of unnatural death.

A Monte Carlo-based model for steady-state diffuse reflectance spectrometry in human skin: estimation of carbon monoxide concentration in livor mortis.

In terms of physics, the skin can be regarded as an optically turbid medium in which the light is mainly scattered by the collagen fibers, mitochondria and cell nuclei, whereas the absorption is determined by the content of reduced hemoglobin, oxyhemoglobin, bilirubin, and melanin. When the measuring geometry and the illumination spectrum are known, the optical characteristics of the skin can be approximately described by the diffusion and absorption coefficients. These values define the diffusion and absorption probability per unit distance traveled for each wavelength. Based on these parameters, a mathematical skin model was developed with the help of Monte Carlo simulations. By implementing the absorption coefficient of carbon monoxide hemoglobin (CO-Hb) into the skin model, the authors wanted to investigate whether this method is suitable to determine the CO-Hb concentration from spectral reflectance curves of livores. The investigations performed on 28 deaths from CO poisoning so far showed that this is generally possible. In almost all cases, the actual CO-Hb values could be estimated correctly by using the Monte Carlo simulations.

Three subsequent infanticides covered up as SIDS.

Within a period of 9 years a young woman lost 3 daughters during infancy and each time death was attributed to the sudden infant death syndrome. The children had different fathers and died at the ages of 11 weeks, 7 weeks and 2 weeks, respectively. A fourth daughter survived and lives separated from the mother together with her father and is healthy. At autopsy the last of the three deceased infants did not reveal any pre-existing pathological organ findings, except for acute pulmonary emphysema and extensive intra-alveolar bleeding. As a consequence the strong suspicion of mechanical suffocation arose. Subsequent police investigations produced incriminating clues that the first two children had also been suffocated. On confrontation with the autopsy findings and investigation results, the woman confessed that she herself had killed the first two infants by pressing a cushion on their faces. In the case of the third death the baby had been smothered by the child's father who in agreement with the mother put a plastic film on mouth and nostrils.

Detachment of the periosteum and soot staining of its underside in contact shots to the cerebral cranium.

Contact gunshot wounds are usually characterized by a muzzle imprint, a powder cavity ("pocket"), the presence of carboxyhemoglobin and often also stellate tears of the skin radiating from the bullet entrance hole. In shots to the cerebral cranium an additional sign may be observed around the bone defect: the periosteum is detached and reflected with soot on the underside. The frequency and possible causes of these periosteal findings are discussed on the basis of 68 contact gunshot wounds from forensic autopsy material and experimental shots fired against the frontal bone of a slaughtered calf.

Heat-mediated changes to the hands and feet mimicking washerwoman's skin.

If the palms of the hands and the soles of the feet of burnt bodies are not or only partially charred, whitish discoloration and wrinkled detachment of the epidermis is often observed. The findings are strongly reminiscent of the so-called washerwoman's skin, as seen after exposure to a moist environment for at least several hours. However, this is not to be expected after exposure to dry heat. What might be conceivable is a swelling of the skin due to the effect of the water used for fighting the fire. On the other hand this phenomenon is also observed in burnt bodies, which demonstrably have not come into contact with water, so that formation seems to be caused by a different mechanism. Moreover there are also histological differences between real washerwoman's skin and the pseudo-washerwoman's skin of fire victims. Whereas in genuine washerwoman's skin the stratum corneum is disaggregated and perinuclear vacuoles are found in the stratum germinativum, burnt bodies with pseudo-washerwoman's skin show detachment of the epidermis due to serum-filled blisters with elongation and palisade arrangement of the nuclei in the stratum basale. Consequently these changes agree with second-degree burns.

[Hypostasis-induced changes in the breast area]. / Abwandlung der Hypostasebefunde in der Mamillenregion.

When the anterior thoracic wall is within the hypostatic area, postmortem lividity in the region of the nipples and their immediate vicinity is less intense or absent. Where hypostatic skin haemorrhages (so-called vibices) are present, these are also found outside the areola of the nipple only. This phenomenon is visible not only externally, but is particularly pronounced on the cut surface. A possible explanation may be the different distribution pattern of connective tissue, smooth muscles and blood vessels inside and outside the areola mammae. Based on 13 cases from the forensic autopsy material--mostly drug related deaths--the macromorphological findings and their histological correlates are presented.

Prevalence of nicotine consumption in drug deaths.

One hundred consecutive drug death victims autopsied at the Institute of Forensic Medicine, University of Freiburg, between 1995 and 1997 were studied retrospectively as to whether the drug users had also consumed nicotine. The study included histological examination of the lung tissue for smoker cells and radioimmunological as well as GC-MS assays of the urine for cotinine, the primary metabolite of nicotine. It was found that 98 out of 100 drug victims had consumed nicotine in addition to illicit drugs or replacements. Yellowish-brown discolorations on the middle and index fingers were discernible in 44 drug victims, whereas fresh or scarred burns due to glowing cigarettes were found in six deceased drug consumers. Diseases of the bronchial system typical of heavy smokers were seen in 35 cases. Siderophages could be demonstrated in 17 of the 100 drug deaths.

[Extent of burn lesions--an analysis of 68 burned cadavers]. / Zum Ausmass der Brandzehrung--eine Analyse von 68 Brandleichen.

The burned bodies (n = 68) autopsied at the Freiburg Institute of Forensic Medicine in the years 1996-2001 (until the end of February) were examined with regard to the extent of consumption by the fire using the classifications suggested by Eckert et al., Maxeiner, Glassman and Crow, and Gerling et al. Further classification parameters were exposure of the body cavities and amputation of extremities as a result of the fire. Most cases were accidental deaths (approximately 75%). The fires occurred mainly in buildings (57%) or vehicles (34%); in 6 cases the burning took place in the open air. In most cases the degree of consumption by the fire was slight to moderate. Only 15% of the burned bodies showed extensive destruction with severe loss of soft tissue and shrinking or amputation of the extremities. In one case the soft tissue was completely destroyed with fragmentation of the calcined skeletal remains. In bodies recovered from house fired the extent of consumption by the fire was usually less pronounced than in bodies retrieved from burned-out vehicles.

[A case of fatal amniotic fluid embolism]. / Zur Kasuistik der letalen Fruchtwasserembolie.

A 31-year-old pregnant woman (multipara), who was near the expected date of birth, was found dead in the joint flat by her partner. She was lying beside the bed and showed burns on the front of the body caused postmortem by contact with a radiator. Autopsy revealed a rupture of the fetal membranes, the inner layers of the uterus and a large vein. After centrifugation, the supernatant of the blood from the right half of the heart was turbid and contained small corpuscular amniotic fluid components. The diagnosis of amniotic fluid embolism could be confirmed histologically. In the pulmonary vessels of the mother meconium, lanugo hairs and epidermic scales could be demonstrated; in addition the fetal horny lamellae were confirmed immunohistochemically (using monoclonal antibody against cytokeratin).

Post-mortem detection and identification of sildenafil (Viagra) and its metabolites by LC/MS and LC/MS/MS.

The highly putrefied corpse of an 80-year-old man was found in the apartment which he had rented to a prostitute. A package of Viagra 25 was found beside the corpse and three tablets were missing. Autopsy revealed severe coronary artery sclerosis as well as signs of previous myocardial infarctions. For the detection and identification of sildenafil and three metabolites in urine and tissue samples, solid-phase extraction, LC/MS and MS/MS methods were developed. Blood was not available for toxicological analysis due to the putrefaction. For method development, urine from a volunteer who had ingested 25 mg sildenafil was collected over 8 h, and three metabolites were identified by MS/MS. These metabolites were also found in the victim's urine. These findings prove that sildenafil was taken some time prior to death, but the causality of sildenafil intake and fatal cardiac failure could not be proven, since no blood was available for analysis. However, the administration of sildenafil was contraindicated due to several previous myocardial infarctions.