A new staining method for constriction marks in skin

A modified Poley's acid fuchsin-methyl green stain was used to demonstrate ligature marks in tissues taken at autopsy. This stain was compared in 30 cases with haematoxylin-eosin, Mallory's trichrome and Ogata's picro-indigocarmine stains. Using the modified Poley method, it was possible to demonstrate the compression mark in corpses even when post-mortem changes were advanced. The method was found useful in evaluating the cases when the force used was minimal or when the mark was atypical using the usual haematoxylin-eosin method.     

A new method for casting three-dimensional shoeprints and tire marks with dental stone

Dental stone is used as the major material for recovering three-dimensional shoeprints and tire tracks from crime scenes. The procedure for using dental stone sparsely changed over the years. There are two common methods for mixing dental stone: (i) a premeasured amount of dental stone is put in a zip-lock bag to which water is added, and (ii) the water and dental stone are mixed in a bucket. We suggest a novel rapid and efficient method of mixing dental stone and water in a bottle. These methods were compared at equal conditions. The parameters measured were the number of air bubbles, the strength of the cast, the ease of use, and the sharpness and quality of the accidental characteristics present in the cast. The proposed bottle method has the advantages of both the bucket and the zip-lock methods hence it combines strength, sharpness, high quality, and ease of use.     

A method for studying knife tool marks on bone

The characteristics of knife tool marks retained on hard tissues can be used to outline the shape and angle of a knife. The purpose of this study was to describe such marks on bone tissues that had been chopped with knives. A chopping stage with a gravity accelerator and a fixed bone platform was designed to reconstruct the chopping action. A digital microscope was also used to measure the knife angle (θ) and retained V-shape tool mark angle (ψ) in a pig skull. The κ value (elasticity coefficient; θ/ψ) was derived and recorded after the knife angle (θ) and the accompanied velocity were compared with the proportional impulsive force of the knife and ψ on the bone. The constant impulsive force revealed a correlation between the V-shape tool mark angle (ψ) and the elasticity coefficient (κ). These results describe the tool marks--crucial in the medicolegal investigation--of a knife on hard tissues.     

A photometric method for the quantitative mapping of parallel striated marks

A scanning detection system has been developed to provide quantitative surface profile information from cases of parallel striated marks of the type encountered in the forensic laboratory. Details of the scanning system, casting methods and calibration technique are described. Some examples of the results from flat and curved surfaces are presented.     

An integrated technique for the analysis of skin bite marks

The high number of murder, rape, and child abuse cases in South Africa has led to increased numbers of bite mark cases being heard in high courts. Objective analysis to match perpetrators to bite marks at crime scenes must be able to withstand vigorous cross-examination to be of value in conviction of perpetrators. An analysis technique is described in four stages, namely determination of the mark to be a human bite mark, pattern association analysis, metric analysis and comparison with the population data, and illustrated by a real case study. New and accepted techniques are combined to determine the likelihood ratio of guilt expressed as one of a range of conclusions described in the paper. Each stage of the analysis adds to the confirmation (or rejection) of concordance between the dental features present on the victim and the dentition of the suspect. The results illustrate identification to a high degree of certainty.     

A new biochemical method for estimation of postmortem time.

Hypoxanthine (Hx) is formed by hypoxic degradation of adenosine monophosphate (AMP) and might be elevated due to antemortem hypoxia. However, it also increases after cessation of the life processes. Until now measurements of potassium in corpus vitreous humor have been used by forensic pathologists to determine postmortem time. In this study the influence of postmortem time and temperature on vitreous humor Hx and potassium levels were compared. Repeated sampling of vitreous humor was performed in 87 subjects with known time of death and diagnosis. The bodies were kept at either 5 degrees C, 10 degrees C, 15 degrees C or 23 degrees C. Hx was measured by means of HPLC and potassium by flame photometry. In 19 subjects from whom samples were obtained within 1.5 h after death, the normal level of Hx could be estimated to be 7.6 mumol/l and that of potassium to be 5.8 mmol/l. The spread of the potassium levels measured shortly after death was much greater than for the corresponding Hx levels. In the four temperature groups the Hx level increased 4.2, 5.1, 6.2 and 8.8 mumol/l per h, respectively, whereas the corresponding figures for potassium were 0.17, 0.20, 0.25 and 0.30 mmol/l per h. The vitreous humor concentration of both Hx and potassium increases fairly linearly after death. The slopes are steeper with increasing temperature. Since the scatter of the levels is greater for potassium than for Hx, the latter parameter seems to be better suited for the determination of time of death in cases without antemortem hypoxia, especially during the first 24 h.     

A new method for softening mummified fingers

Proposed methods for softening mummified fingers have been either unsuccessful in adequately softening the fingers or have been highly destructive. A simple technique based on an entirely new concept utilizing disodium ethylenediamine tetraacetic acid in a detergent solution adjusted to a pH of 7.5 has been successfully used to obtain satisfactory to good fingerprints over the past ten years in every case attempted.     

一种用于降解DNA样本的性别鉴定方法

目的　建立一种采用PCR技术对降解DNA样本进行性别鉴定的新方法。　方法　采用针对amelogenin基因X染色体外显子 3bp缺失设计的引物AMELU1及AMELD1,对在室温环境下放置 5～ 15年的男、女血痕标本各 5 0例、毛发各 2 0例、骨骼各 2 0例以及现场提取 5 - - 2 0天的男、女腐败肌肉各 10例标本中提取的降解DNA样本进行扩增。用PAG( 9%T ,3 %C)电泳、银染显带检测扩增产物。　结果　所有样本均得到正确结果 ,男性检材表现为 83bp的Y特异性及 80bp的X特异性 2条谱带 ,而女性检材仅有 1条 80bp的X特异性谱带。　结论　用针对amelogenin基因X染色体外显子 3bp缺失设计的引物AMELU1及AMELD1鉴定性别的方法灵敏、可靠、方便 ,是降解DNA检材性别鉴定十分理想的方法。     

A new method for detecting diatoms in human organs

A new method for diatom detection is described. It includes an ultrasonic irradiation procedure with the use of a tissue solubilizer. The method is easy to carry out and is less time-consuming than previous techniques.     

A silver staining method for the detection of polymorphic proteins in minute bloodstains after isoelectric focusing

A silver staining method has been developed to study polymorphic proteins in bloodstains after isoelectric focusing. This method is highly sensitive and permits the detection of polymorphic proteins (i.e. alpha 1-antitrypsin, Gc and Tf C subtypes) in bloodstains as small as 0.2 microliter or less. The method is simple and reproducible and can be used after immunofixation. Blood stains can be identified after longer storage periods than is possible by using conventional staining methods.     

A method for collection of gunshot residues from skin and other surfaces

A method of collecting gunshot residues from the skin of persons who have been injured by firearms has been developed. The method uses a commercially available, adhesive, transparent plastic film. This method is also useful for collecting gunshot residues from other objects, such as leather. The shooting distance is later estimated by ocular, microscopic or IR examination in combination with various chemographic tests.     

利用髋骨进行性别判别的的新方法

通过已知性别的干燥成人髋骨190副（男123副，女67副）进行研究，发现髋骨上界线的弧长、界线的弦长和孤高，以及髋臼的直径等值均存在着显著的性别差异。四项指标的单一性别判别准确率分别为78．42％、73．68％、74．74％及72．63％。分别利用前三项指标与髋臼直径的比值作为性别判别公式，判别准确率可达91．58％、8．95％、85．26％。利用筋骨进行性别判别建立新的方法。     

A new method for typing haptoglobin in bloodstains using immobilized allo A lectin

Allo A lectin from the beetle, which is beta-D-galactose specific, reacts to haptoglobin but not to hemoglobin. The use of allo A-Sepharose for typing haptoglobin in bloodstains helped eliminate hemoglobin from the bloodstain extract and presented highly resolved haptoglobin patterns by disc gel electrophoresis. This method is simple and rapid for typing haptoglobin in bloodstains and can be easily used in forensic science laboratories.     

A new method for locating saliva stains-spotty paper for spotting spit

A convenient method of locating saliva stains has been devised. Filter paper covered with blue coloured starch fragments is laid on the material to be tested. Salivary amylase hydrolyses the starch on the areas of paper corresponding to saliva stains, which are then delineated as clear zones whereas negative areas remain speckled with blue particles.     

A forensic classification of distortion in human bite marks

The occurrence of distortion in human bite marks is well recognised. A forensic classification of distortion is suggested which is based upon the causative factors and their inter-relationships. The terms primary distortion and secondary distortion are introduced and described. The objective of this classification is to emphasise the need for a scientific approach to the recognition and interpretation of the types of distortion found in human bite marks. The relationships between distortion, distinctive features and superimposition techniques in bite mark analysis are discussed.     

Measurements of ulna--a new method for determination of sex.

Identification of sex from skeleton parts is of paramount importance to medicolegal investigations. The present study makes an attempt to assess sex from the ulna by devising new measurements for fragmentary bones. Dry and adult ulnae (100 male and 60 female) of Madhya Pradesh, India were subjected to three measurements (Olecranon--coronoid angle, length, and width of inferior medial trochlear notch) that were devised specifically for this study. The data were analyzed using discriminant function analysis. Direct analysis using single or multiple variables revealed the Olecranon-Coronoid angle as the best single parameter, yielding 85% accuracy. Measurements of the inferior medial trochlear notch have an additional advantage of being used in fragmentary bone where only the upper end is available. The calibrated discriminant functions correctly classified 90.6% of all males and females in an independent test sample.     

TFD-2纸张手印快速显现系统的应用

目的介绍一种利用特殊的红外热成像技术显现常见纸张上汗潜手印的新方法。方法利用英国Foster4-Freeman公司生产的TFD-2纸张手印快速显现系统,通过特殊的红外热成像技术,使汗潜手印呈现强烈荧光,从而显现手印。结果红外热成像方法处理后,汗潜手印在特种激发光（带宽为450nm-510nm）激发下显出较强的橙色荧光;持续处理后,汗潜手印在自然光下呈棕褐色,并在短波紫外光源（254nm）激发下也可显出清晰连贯的手印纹线;而且,新鲜和陈旧手印均有较好的显现效果。结论TFD-2纸张手印快速显现系统显现纸张上汗潜手印的方法,具有操作简单、快速安全、无需化学试剂、显现效果明显的特点,适合推广使用。     

一种收集衣服上脱落细胞的新方法

目的建立一种生物脱落细胞的微量提取新方法。方法利用一套自制的“生物细胞提取仪”无损提取衣物等载体上的人体脱落细胞,采用Chelex-100法提取DNA,用不同的试剂盒进行STR复合扩增检验。结果10例检材都得到16个基因座成功分型。结论用该方法提取微量细胞DNA,可获得满意的DNA分型。