Practical value of LDH-X determination for the detection of sperm traces

The examination of 38 stains collected in sexual offences provided spermatozoa-positive, LDH-X-negative results in 4 samples and spermatozoa-negative, LDH-X-positive results in 6 samples. The results suggest that besides the microscopic detection of spermatozoa the demonstration of LDH-X should be performed in medicolegal identification of seminal stains.     

Visualization of biological traces on evidence by ninhydrin

Because of possible contamination of samples with PCR inhibitors and to avoid the typing of mixed profiles the source material for forensic DNA investigations should be collected as directly and securely as possible from the evidence. This approach requires a detectability of the source material which is often not given. The procedure introduced here using selected cases enables visualization of DNA-containing materials on evidence and hence controlled analysis. For this purpose the specimen is treated with ninhydrin. A following dye reaction verifies the presence of biological material, which possibly contains DNA. An impact on subsequent STR-analysis was not observed.     

Forensic textile fiber examination across the USA and Europe.

Crime laboratories in the USA, who undertake fiber examinations, together with members of the European Fibres Group (plus representatives from Israel, Japan, Canada, and Australia) were surveyed in 1994 and 1995, respectively, and asked to provide subject-specific information relating to personnel, equipment, training, quality control, and techniques available. The information obtained showed that generally more fiber casework is carried out in Europe than in the USA. Most laboratories are quite well equipped but those in Europe seem to be able to obtain more state-of-the-art instrumentation. Proficiency testing and peer review is accepted practice worldwide. Americans appear to update fiber collections on a more regular basis than Europeans but both keep literature up to date. Contamination is a major issue, as with all areas of trace evidence. The results from the survey suggest that minimum standards are clearly not always being observed. Careful consideration also needs to be given as to whether legitimate contact could have occurred prior to an offense being committed. The standard of forensic fiber examination worldwide is generally high. With laboratory management continuing to support the work of the Scientific Working Group for Materials and the European Fibres Group and by instigating "best practice" as set out in their guidelines, standards should continue to improve.     

A new test for evaluating Eighth Amendment challenges to lethal injections

An explosion of Eighth Amendment challenges to lethal injection protocols has struck the federal courts. The Supreme Court's recent decision in Hill v. McDonough,1 which empowered prisoners to bring challenges to lethal injection procedures under 42 U.S.C. para. 1983, has facilitated a flood of new lethal injection cases. In response, several courts have ordered states to alter their protocols, spurring other capital inmates to litigate such challenges. Distressingly, the courts evaluating these claims have almost no law to guide them. The last Supreme Court decision applying the Eighth Amendment to a method of execution was written in 1947; that case, Louisiana ex rel. Francis v. Resweber,2 occurred before the Eighth Amendment was applied to the states and resulted in a 4-1-4 split. Although lower courts have heard numerous challenges to execution methods, few have analyzed the constitutional validity of a method of execution in detail. Making matters worse, courts that find Eighth Amendment violations must craft equitable remedies that often amount to entirely new execution protocols. No clear precedent exists to guide courts in formulating such remedies. This Note proposes a legal standard for the administration of Eighth Amendment method-of-execution claims, focusing on lethal injection cases. Part I describes lethal injection procedures and summarizes recent litigation. Part II discusses the difficulty of evaluating lethal injection claims, analyzing both general difficulties in interpreting the Eighth Amendment and specific difficulties associated with lethal injection cases. Part III proposes a standard for addressing method-of-execution claims that attempts to balance a prisoner's interest in a painless execution with a state's interest in conducting executions efficiently. Part IV discusses remedies for unconstitutional procedures. Part V concludes.     

Inter-comparison of unrelated fiber evidence

The foreign textile fibers recovered from one item of evidence from each of 20 unrelated crimes in three categories (bank robbery, kidnapping, and homicide) were cross-compared. The items of evidence were scraped to remove the trace evidence and a sample of the collected fibers was examined using a standard scheme of analysis. The fibers were examined with light microscopy (including polarized light microscopy), fluorescence microscopy, and microspectrophotometry. The fibers were divided into natural and manufactured groups and then categorized by color and generic (polymer) class. Cross-comparing all 2083 fibers resulted in 2,168,403 comparisons, after removing duplicate (same fiber) comparisons. Colorless and denim fibers were excluded from this study. No two fibers were found to exhibit the same microscopic characteristics and analytical properties. Therefore, it is rare to find two unrelated items that have foreign fibers that are analytically indistinguishable. These results corroborate other population studies conducted in Europe and target fiber studies conducted both in the US and in Europe.     

Water-soaked evidence: detectability of explosive traces after immersion in water

Various factors governing the detectability of explosive traces after being soaked in water were studied. The variables are: the type of the surface (surfaces liable to be found in aircraft were chosen), the type of explosive, the type of water (tap or seawater), and movement of the immersed surface in the water. The maximal immersion times (tmax) after which explosive detection was possible were evaluated. This datum was found to depend on the type of explosive (one of the important factors is solubility in water), the surface material and the environmental conditions (tap or seawater movement). Detection of PETN on high-density polyethylene, linoleum, glass and aluminum, by the chemical Explosive Testing Kit (ETK), was possible even after a month of soaking in seawater. In addition, it has been found that movement of bulk water around the samples with deposited explosives considerably decreases tmax values. It is, therefore, recommended to retrieve samples for explosive analysis as soon as possible and in areas where the currents of water is minimal.     

Investigation of the new possibility of mathematical processing of Raman spectra for dating documents

The use of spectral analysis methods to determine the age of writing inks is an important forensic task. However, the use of spectral data for this purpose has a number of limitations and difficulties. This paper considers the application of the Raman spectroscopy method to an urgent forensic task. The known mechanisms of dye degradation are analyzed; Raman bands are identified that are related to the age of the sample. In a sample of 5 randomly selected writing inks, temporary markers were identified. Narrow sections of Raman spectra containing characteristic lines were used for analysis. It was shown that processing narrow sections of the Raman spectra using the PCA chemometric method allowed the separation of writing inks into groups (clusters) corresponding to different creation intervals.     

A textile fibre survey as an aid to the interpretation of fibre evidence in the Sydney region.

Frequency figures of the fibre population on textile cinema seats were measured in Sydney, Australia, in winter. Sixteen seats were analysed from a very popular cinema complex, with 3025 fibres classified according to colour, generic class and fluorescence properties (100 grey-black cotton fibres only). The recovered fibres were mostly natural fibres (84%) with cotton the most common generic type (70%). On the contrary, man made fibres were relatively rare (15%) with rayon constituting the majority of these (51%). The most common colour/generic class combinations were grey-black cotton (33%) and blue cotton (30%) accounting for 63% of the total population. All other frequencies were below 5%, most below 1% using only the two properties of colour and generic class. Fluorescence properties were found to be very discriminating as far as grey-black cotton fibres were concerned. These features are considered and discussed and in particular, to emphasise the significance of fibres as evidence of contact.     

Construction of a roller device for the collection of hair and fiber evidence.

The discovery of hair and fiber evidence can be of critical importance in the investigation of crimes, particularly violent crimes. A procedure is described for the construction and assembly of a roller device that utilizes readily available components and single-sided adhesive tape. The advantages over previously described roller devices include decreases in both the potential for contamination and the time required for construction of the device, as well as the ability to disinfect all of the roller components.     

A statistical criterion for the value of evidence: Application to the evaluation of the results of paint spectral analysis

The paper describes a method for the quantitative comparison of slightly differing infrared spectra. The method is based on a comparison of the differences in absorbance of some selected band pairs which represent identification features of infrared spectra. An optimal combination of band pairs was chosen using two methods: a graphical method based on the validity of Beer's law (method I) and a purely statistical method (method II). The spectra characterized by the selected features were compared and the significance of differences between them was tested using the mathematical Hotelling's T² test. It was found that the method developed enables the quantitative and objective evaluation of the statistical significance of differences between compared spectra.     

Bayesian framework for the evaluation of fiber evidence in a double murder--a case report

Fiber evidence found on a suspect vehicle was the only useful trace to reconstruct the dynamics of the transportation of two corpses. Optical microscopy, UV-Vis microspectrophotometry and infrared analysis were employed to compare fibers recovered in the trunk of a car to those of the blankets composing the wrapping in which the victims had been hidden. A "pseudo-1:1" taping permitted to reconstruct the spatial distribution of the traces and to further strengthen the support to one of the hypotheses. The Likelihood Ratio (LR) was calculated, in order to quantify the support given by forensic evidence to the explanations proposed. A generalization of the Likelihood Ratio equation to cases analogous to this has been derived. Fibers were the only traces that helped in the corroboration of the crime scenario, being absent any DNA, fingerprints and ballistic evidence.     

司法精神病鉴定证据价值论

司法精神病鉴定作为科学的认识活动,由于其本身的固有属性及诸多因素之影响,其鉴定结论在很大程度上具有不确定性.因此,要求法官在采信鉴定结论之前,必须结合司法精神病鉴定的特点、司法精神病鉴定结论的证据属性,分析、判断其证据价值.并通过对相关制度的完善,充分发挥庭审质证之功能,帮助法官提升对司法精神病鏊定结论形成内心确信的准确性.     

A field evaluation of the VIPER system: a new technique for eliciting eyewitness identification evidence

Abstract

The main aim of the study was to investigate the rate of claimed false confession during police questioning and identify variables that best discriminate between false confessors and non-false confessors. The participants were 24 627 high school students in seven countries in Europe. Out of 2726 who had been interrogated by the police as a suspect, 375 (13.8%) claimed to have made false confessions to the police. Logistic regression analyses showed that for both boys and girls, having attended substance abuse therapy, been attacked and bullied, and having committed a burglary, significantly discriminated between the false confessor and non-false confessor. In addition for boys, having been sexually abused by an adult outside the family was the single best predictor. The study shows the importance of history of victimization and substance misuse among adolescents in relation to giving a false confession to police during interrogation.     

Bayesian networks and the value of the evidence for the forensic two-trace transfer problem*

Forensic scientists face increasingly complex inference problems for evaluating likelihood ratios (LRs) for an appropriate pair of propositions. Up to now, scientists and statisticians have derived LR formulae using an algebraic approach. However, this approach reaches its limits when addressing cases with an increasing number of variables and dependence relationships between these variables. In this study, we suggest using a graphical approach, based on the construction of Bayesian networks (BNs). We first construct a BN that captures the problem, and then deduce the expression for calculating the LR from this model to compare it with existing LR formulae. We illustrate this idea by applying it to the evaluation of an activity level LR in the context of the two-trace transfer problem. Our approach allows us to relax assumptions made in previous LR developments, produce a new LR formula for the two-trace transfer problem and generalize this scenario to n traces.     

参与自杀的可罚性研究

生命属于个人法益。从为了保护本人利益的"家长主义"立场出发,应否认法益主体对自己生命的自己决定权,亦即自杀具有违法性。但自杀因源于自己决定,其违法性低,不值得处罚;从刑事政策的视角来看,也欠缺处罚自杀的必要性和合理性。参与自杀是否定、侵犯他人生命权的行为,相较于自杀者的自杀意思,更有必要保护其生命的绝对价值。参与自杀在我国应以(情节较轻的)故意杀人罪的教唆犯或者帮助犯论处。参与自杀与利用被害人为工具的故意杀人罪的间接正犯之性质及其刑罚效果大相径庭,应严格区分两者的界限。     

The influence of the type of accelerant, type of burned material, time of burning and availability of air on the possibility of detection of accelerants traces

The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between lighting and extinguishing of fire and the air availability level. The obtained results show that, among investigated factors, the type of burned material has the greatest influence. The other factors, with regard to their influence, could be ranked in descending order as follows: 'other' (hard to determine and regulate factors), type of accelerant, time of burning and air availability. 'Other' factors include arrangement of the burned material and dispersion of the accelerant.     

The influence of the type of accelerant, type of burned material, time of burning and availability of air on the possibility of detection of accelerants traces

The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between lighting and extinguishing of fire and the air availability level. The obtained results show that, among investigated factors, the type of burned material has the greatest influence. The other factors, with regard to their influence, could be ranked in descending order as follows: ‘other’ (hard to determine and regulate factors), type of accelerant, time of burning and air availability. ‘Other’ factors include arrangement of the burned material and dispersion of the accelerant.