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.

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.

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.

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.

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.

Use of specific oligonucleotides for direct enumeration of Listeria monocytogenes in food samples by colony hybridization and rapid detection by PCR.

Two 18-mer oligonucleotides derived from the sequence of hly, the gene coding for listeriolysin O, were shown to be specific for Listeria monocytogenes in the genus Listeria in colony hybridization tests. The oligonucleotides did not hybridize with any of the bacterial species found in food and co-isolated with Listeria on selective media. They were used in colony hybridization tests for enumeration of L. monocytogenes present in food samples after direct plating on selective media plates. In addition, two 24-mer oligonucleotides, each including the sequence of one of the 18-mers, were successfully used for the PCR-based detection of L. monocytogenes bacilli present in food samples after 48-h enrichment period. Using this technique, as little as 10(2) bacteria per ml of enrichment broth can be detected.

Effects of the calmodulin antagonists fendiline and calmidazolium on aggregation, secretion of ATP, and internal calcium in washed human platelets.

Ca2(+)-calmodulin dependent phosphorylation of myosin is essential for the induction of platelet shape change and subsequent reactions. Therefore, we studied the effects of the calmodulin antagonists fendiline and calmidazolium on the thrombin-induced aggregation, secretion of ATP, and increases in the intracellular free calcium concentration ([Ca2+]i) in washed human platelets in the absence and presence of extracellular Ca2+. In Ca2+ free medium, fendiline (10-100 microM) and calmidazolium (3-30 microM) concentration-dependently inhibited aggregation. The effect of fendiline could be partly reversed by extracellular Ca2+ and higher thrombin concentrations. Furthermore, aggregations induced by the calcium ionophore ionomycin and by the protein kinase C-activator 4-beta-phorbol 12-myristate 13-acetate were inhibited by fendiline, although to a smaller degree than the thrombin-induced aggregation. Thrombin-induced secretion of ATP was attenuated by low concentrations of fendiline (1-3 microM) and calmidazolium (1 microM) but enhanced by higher concentrations (10-30 and 3-10 microM, respectively), independently of extracellular Ca2+. Fendiline (1-10 microM) did not affect [Ca2+]i in resting and thrombin-stimulated platelets. At higher concentrations (30-100 microM), it induced increases in [Ca2+]i in unstimulated platelets and attenuated the response to thrombin in Ca2+ free medium, whereas thrombin-induced Ca2+ influx was markedly enhanced. Similar results were obtained with calmidazolium (1-3 microM). These stimulating effects on ATP secretion and on [Ca2+]i of fendiline and calmidazolium may be attributed to interactions with platelet membranes by which the permeability of small cations is increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Lethal monointoxication by overdosage of MDEA.

A 19-year-old man died after the intake of ten tablets of Ecstasy containing 3,4-methyl-enedioxy-N-ethylamphetamine (MDEA) as the main active ingredient. According to an eyewitness the symptoms of intoxication were strong sweating, sudden aggressiveness followed by hallucinations, subsequent failure of motoric coordination, severe spasms of arms and back, complete depression of the respiratory system, unconsciousness, and collapse. Resuscitation by an emergency doctor failed. Major autopsy findings were severe vascular congestion of all internal organs, liquid post-mortem blood, numerous subpleural and subepicardial petechial haemorrhages. By GC/MS analysis, MDEA was found in large amounts in serum (12 mg/l in femoral vein, 22 mg/l in heart blood serum), urine (201 mg/l), brain (18 to 28 mg/l) and in other tissue samples. Scalp-hair was highly positive for MDEA (17 ng/mg). Besides MDEA and its metabolites only trace amounts of MDMA could be found in urine and blood; no other drugs were detected. It can be concluded that the cause of death was a monointoxication by overdosage of MDEA.

Pellet embolization to the right atrium following double shotgun injury.

A 28-year-old man sustained two shotgun injuries of the left inguinal region from a distance of about 1.5 m by simultaneous discharge of both shells from a sawn-off double-barrelled 16-bore shotgun (diameter of the lead pellets, 4 mm). The first X-ray examination carried out soon after hospital admission showed a single embolized pellet near the right margin of the cardiac silhouette. Eight months later, the man committed suicide by drug intoxication. At autopsy, the embolized pellet was found embedded between the pectinate muscles of the right atrium. On the basis of the reported case and with reference to the pertinent literature, the paper points out the medico-legal aspects of venous bullet/pellet embolism and the risk of lead poisoning after shotgun injury.

Spectrophotometric evaluation of postmortem lividity.

Under low ambient temperatures normally bluish postmortem lividity adopts a bright red or pink colour due to resaturation of haemoglobin with O2. The most important differential diagnosis in the presence of pink hypostasis is carbon monoxide poisoning. To answer the question if objective measuring methods allow differentiation of hypostasis with regard to cold exposition or carbon monoxide poisoning, spectrophotometric measurements were performed and the colorimetric measures as well as the spectral reflectance curves of the postmortem lividity were determined. The colorimetric measures CIE-L*a*b* showed similar values for all bright red livores mortis; differentiation between CO intoxication and cold exposition was not possible. Reflectance curves of pink hypostasis after cold storage showed the typical pattern of O2-rich blood with reflectance minima at wavelengths 541 nm and 576 nm and a reflectance maximum at 560 nm. Pink hypostasis because of carbon monoxide poisoning showed a shift of the reflectance maximum toward 555 nm and a flattened curve in all cases with COHb concentrations exceeding 52%, whereas these changes were not regularly observed with lower COHb levels.

The degree of destruction of human bodies in relation to the duration of the fire.

The changes occurring during cremation were watched and documented in 15 undissected bodies to be cremated. It was found that at temperatures between 670 and 810 degrees C the body showed the "pugilistic attitude" after about 10 minutes. After 20 minutes the calvaria was free from any soft tissue and fissures of the tabula externa could be noticed. The body cavities became visible after approximately 30 minutes, so that the organs were exposed. Forty minutes after cremation had started, the internal organs were severely shrunken and showed a net-like or sponge-like structure. After about 50 minutes the extremities were destroyed to an extent leaving only the torso which broke apart after 1-1.5 hours. The complete incineration of a human body took about 2-3 hours.

The changing phenomenology of drug death over the years.

When inspecting the scene the circumstances under which a body is found and the findings on the body surface may give first clues to premortal drug abuse. Besides fresh and/or old injection marks tattoos, underweight and signs of physical neglect, especially after long-term abuse, are mentioned in literature. The incidence of such externally visible physical signs of drug abuse was systematically investigated in 100 consecutive drug deaths occurring from 1995 to 1997. Sixty-eight percent of the bodies were found in the apartments of the deceased or those of friends, 11% in public restrooms or the washrooms of restaurants. The so-called body dumping was seen in three cases. In 61% externally visible, fresh injection marks were found; on dissection of the subcutaneous veins, residues of previous injections were found in 95% of the cases. Tattoos were present in 63%. In 8% there was clear evidence of physical neglect. Eighty-six percent of the drug victims had a normal nutritional status.

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.

Fractures of the base of the skull in charred bodies--post-mortem heat injuries or signs of mechanical traumatisation?

Based on a recent case, in which an expert opinion had to be prepared, the question was investigated if fractures of the base of the skull can result from the influence of heat on the human skull. Neither the retrospective analysis of autopsy records nor the prospective examination of charred bodies revealed any cases with heat-induced fractures of the base of the skull. Observation of cremations showed that the changes caused by the fire followed certain rules: fractures of the calvaria were seen after approximately 20 min; the base of the skull became exposed after about 45 to 60 min. In none of the 20 cremations watched could any fractures of the base of the skull be detected.

Transfer of biological traces in cases of hanging and ligature strangulation.

In hanging and ligature strangulation, the noose mostly causes a mark or groove which is formed partly by compression of the skin and partly by abrasion with loss of the upper epidermal layers. The horny scales abraded from the neck may be transferred to the strangulation device or to the interposed textiles where they are sometimes visible at stereomicroscopic examination or even to the naked eye as silver-grey particles. The morphologic features of the epidermal transfer due to hanging and ligature strangulation is demonstrated by 14 case examples. The biological traces may be sufficient for comparative DNA typing by means of PCR-based methods. In 9 out of the 14 cases, genomic DNA typing was successful. Analysis of mtDNA succeeded in another two cases, although genomic DNA could not be detected. Beside the accumulation of solid epidermic particles the paper describes deposition of serous and fatty tissue fluid at the ligature (mainly adjacent to skin ridges).

Confirmation of the identity of human skeletal remains using Multiplex PCR Amplification and Typing Kits.

The identify of human skeletal remains found in a wooded area approximately one year after the person was reported missing was provisionally established by routine methods and circumstantial evidence. Multiplex PCR systems--the AmpliType PM PCR Amplification and Typing Kit and the GenePrint STR Triplex Amplification and Typing Kit--were used to confirm the identification. DNA profiles from femur bone from the remains were compared with profiles derived from head hairs from a hairbrush recovered in the missing woman's apartment. In addition, a sex typing procedure using the X-Y homologous gene amelogenin was carried out. This is the first report of a case using commercially available multiplex PCR amplification and typing kits to confirm the identity of skeletal remains.

Clinical findings in the medico-legal investigation of arsonists.

Criminal and pathological arson is often committed with the help of fire accelerants. The formation of an explosive gas/air mixture may lead to an explosion whose extent and fierceness is often underestimated by the offenders. This explosion causes typical heat changes on exposed persons: * Singeing of eyelashes, eyebrows and hair growing near the frontal hairline * Singeing of the beard * Singeing of body hair in regions not covered by clothing (e.g. back of the hand) * In severe cases, skin burns of varying degree (back of hand, face). Such heat-related changes can sometimes be detected weeks after the offence.