The subjectivist interpretation of probability and the problem of individualisation in forensic science

This paper presents and discusses further aspects of the subjectivist interpretation of probability (also known as the ‘personalist’ view of probabilities) as initiated in earlier forensic and legal literature. It shows that operational devices to elicit subjective probabilities – in particular the so-called scoring rules – provide additional arguments in support of the standpoint according to which categorical claims of forensic individualisation do not follow from a formal analysis under that view of probability theory.     

Visualization of latent fingermark corrosion of brass, climatic influence in a comparison between the U.K. and Iraq

Through a comparison of fingermark sweat corrosion of α phase brass in both the U.K. and Iraq, we show how samples from Iraq have improved fingermark corrosion over U.K. samples that require no additional enhancement prior to visualization. Over 50% of Iraqi samples produced fingermark corrosion with full ridge detail compared with 0% from the U.K. X-ray photoelectron spectroscopy analysis of the fingermark corrosion products showed that Iraqi samples exhibit more dezincification with the Zn:Cu ratio averaging 1:1.82 compared with 1:3.07 for U.K. samples. Auger spectroscopy showed the presence of both zinc oxide and copper (I) oxide. No copper (II) was observed on the surface of the corroded brass. Opportunities to exploit the optical properties of these thin film oxides to enhance the visualization of fingermark corrosion are considered, and the potential to use fingermark corrosion of metal as a means of visualizing fingerprints in war zones is discussed.     

An evaluation of the effect of incorporating metal salts into 1,8 diazafluoren-9-one (DFO) formulations for fingermark enhancement

A study into the modification of 1,8-diazafluoren-9-one (DFO) formulations by the additions of metal salts into the working solution is reported. Similar additions have been found to increase the fluorescence of marks developed using other amino acid reagents including 1,2-indandione and the ninhydrin analogue 5-methylthioninhydrin. It was found that adding zinc chloride to give a 1:1 ratio of zinc ions:DFO molecules gave optimum fluorescence, and improvements in performance over the standard DFO formulation were achieved. Attempts to produce equivalent formulations with iron, nickel and palladium chlorides were unsuccessful. In a comparative trial with a 1,2-indandione-zinc formulation on brown paper and cardboard substrates, 1,2-indandione-zinc gave superior results and it was decided to focus further research on this reagent instead of DFO-zinc.     

The effect of household corrosive substances on latent fingermark development in the context of deliberate corrosive substance attacks

Corrosive substance attacks (CSA) are a prevalent issue in the UK with 525 offenses involving a corrosive substance reported to the police in the year ending March 2022. Easy availability, low cost, and concealability in public are common reasons for choosing a corrosive substance as a weapon. The Metropolitan Police revealed that 68% of 1849 CSA cases resulted in no suspect identified or evidential difficulties. There is limited research into the effect of corrosive substances on latent fingermarks. This study aimed to determine the potential for fingermarks to be recovered from surfaces exposed to a household corrosive substance within the context of a deliberate CSA. Natural and sebaceous-loaded fingermarks were exposed to Domestos bleach, Harpic limescale remover (hydrochloric acid-based) and lemon juice. Harpic limescale remover had the most detrimental effect, with only 7.1% of fingermarks (n = 378) exposed being identifiable (defined as sufficient clear ridge detail for identification) after enhancement, followed by bleach with only 10.3% of fingermarks (n = 378) identifiable. Lemon juice had the least detrimental effect on fingermarks, with 40.5% fingermarks (n = 378) identifiable compared to 53.4% for the controls (not exposed to any substance; n = 378). Throughout the study, fewer natural fingermarks were identifiable after exposure to corrosive substances compared to sebaceous fingermarks which was as expected. Overall, this study demonstrated that there is potential to recover latent fingermarks, depending on their composition, following exposure to a household corrosive substance. This area warrants further research to establish best practice to maximize the potential to recover identifiable fingermarks.     

The identification of individuals by observational gait analysis using closed circuit television footage

This study investigated the ability of individuals with experience in gait analysis to identify people by observing features of gait recorded by closed circuit television cameras (CCTV). Seven experienced analysts each viewed five samples of footage. Each sample showed a “target walker” and five “suspect walkers.” The task of the experienced analysts was to determine which, if any, of the “suspect walkers” was the “target walker.” All of the participant “walkers” wore identical loose fitting clothing to mask anatomical and body contour features, and balaclavas to obscure facial features. The overall results showed that the experienced analysts made a correct decision in 124 of 175 cases (71%), significantly better than would have been expected to have occurred by chance (p < 0.05). A significant variation in correct decisions (p < 0.05) was shown to occur between the various angles from which the footage was recorded, footage recorded in the saggital plane showing the highest number of correct decisions. Significantly more correct decisions (p < 0.05) were also shown to occur when the footage of the “target walker” and that of the “suspect walker” were taken from the same angle. The results suggest that individuals with experience in gait analysis perform well in the comparative identification of suspects from CCTV footage, and therefore do have a role to play as expert witnesses in this field.     

The influence of cleaning agents to the result of abo blood-group determination by the agglutinin-binding test (holzer) at blood stain on articles of clothing (author's transl)]

The blood-group determination in the ABO-system during blood stain testing on articles of clothing is very often affected by various factors. In this research project blood-traces were tested on many different textiles and after treatment of these textiles with some usual washing and cleaning agents by the Agglutinin-binding-test (HOLZER).     

The effect of relative humidity on the effectiveness of the cyanoacrylate fuming process for fingermark development and on the microstructure of the developed marks

Research has been conducted to establish the effect that changes in relative humidity have on both the effectiveness of the cyanoacrylate fuming technique and the microstructures formed by the polymerisation reaction during the development of the marks. The study investigated 'natural' fingermarks and deliberately groomed eccrine and sebaceous marks, all exposed to relative humidity levels in the range 60-100%. It was found that the optimum level of relative humidity for the development of the most high quality marks is approximately 80%, in accord with current recommendations for operational implementation which are based on previous unpublished work. The eccrine constituents of the fingerprints are most influenced by humidity changes. Three humidity regimes were identified, each giving different polycyanoacrylate microstructures. Humidity levels of 60% give flat, film-like structures whereas in the range 70-90% the characteristic noodle-like structure is formed. At higher humidities, thin, flat thread-like growth is observed with some 'collapsed sphere' structures observed close to pores and significant background development. The noodle-like structures are thought to scatter more light and retain fluorescent dye better than the structures formed at other humidity levels. Sebaceous marks produce a very different polymer microstructure, resembling a flat film with some fine nodular structures.     

The effect of zinc chloride, humidity and the substrate on the reaction of 1,2-indanedione-zinc with amino acids in latent fingermark secretions

Anecdotal evidence from forensic practitioners and studies conducted under controlled conditions have indicated that the reaction between 1,2-indanedione and the amino acids present in latent fingermark deposits is highly susceptible to ambient humidity. The addition of catalytic amounts of zinc chloride to the 1,2-indanedione working solution--usually in the order of 1:25 to 1:4 molar ratio (indanedione:zinc)--significantly improves the colour and luminescence of fingermarks treated under dry conditions but appears to have a negligible effect on fingermarks treated in humid environments. The results presented in this paper confirmed that zinc(II) ions added to the 1,2-indanedione working solution act as a Lewis acid catalyst, stabilising a key intermediate during a rate-limiting hydrolysis step. Furthermore, studying the reaction using a chromatography-grade cellulose substrate method previously reported confirmed that cellulose substrates play a major role in facilitating the indanedione-amino acid reaction by acting as a surface catalyst in the early stages of the reaction and by directing the formation of the desired luminescent product (Joullié's Pink).     

The elevation of serum creatine phosphokinase (CPK) at induced hypothermia

The creatine phosphokinase (CPK) elevation of induced hypothermia was elaborated. CPK elevation is a remarkable sign of death due to cold exposure. It appears that the results of the animal experiment indicate that the method could be useful in forensic medical practice as well.     

The discrimination potential of diffuse-reflectance ultraviolet-visible-near infrared spectrophotometry for the forensic analysis of paper

The application of diffuse reflectance UV-VIS-NIR spectroscopy is proposed to differentiate 20 office paper samples, which had been deemed similar by a preliminary visual examination under several different lighting sources. The samples were firstly screened on the basis of the qualitative appearance of their spectra. A further discrimination was obtained by taking into account three parameters: the average reflectivity of the paper samples in the range 680-900nm, and the integrated intensity of the absorption peak in the UV range at 272nm and at 360nm. The homogeneity of these parameters on both sides of the paper sheets was assessed, detecting a very uniform distribution of the optical brighteners. A special focus was posed on the determination of the discriminative power, in order to give a quantitative parameter on the proposed procedure, which is important when reporting results to the Court. The remarkable achievement of differentiating all the examined samples was obtained by UV-VIS spectroscopy, a very less expensive technique which is readily available in practically all forensic laboratories.     

Traumatic potential of colour marking cartridges (FX ammunition)

Colour marking cartridges as the FX ammunition (Simunition Europe, Brussels) are increasingly used by the police for realistic close range combat training. Conversion kits for service weapons of different manufacturers are available. The ballistic data of this ammunition is reported and experimentally verified. The risk of injury seems to be very low, if the recommended protective equipment is used. Small hematomas up to superficial lacerations are to be expected only in areas over a bony support. Shots to the unprotected eye will result in severe injuries.     

The influence of vehicle model and colour on assessments of speed and culpability: the case for (and against) Computer Generated Exhibits (CGE)

Computer Generated Exhibits (CGE) are frequently deployed in legal contexts under the rubric of demonstrative evidence, i.e. to facilitate juror comprehension. However, a number of legal and academic commentators have suggested that the nature of the computerised moving image could exert undue prejudice on decision makers, e.g. judge and/or jury. The current study aimed to assess the manipulation of vehicle characteristics (make and colour) when a road traffic accident was presented in the format of a computer generated animation (CGA). In experiment 1, two groups of subjects watched two different makes of car, a Range Rover Sport and a Volkswagen Touran in a black-and-white format; no significant differences emerged over vehicle model with regards to vehicle speed or overall responsibility for the accident. Experiment 2 presented the same vehicles to four groups of participants in full colour, with the cars in contrasting red or beige; significant differences emerged with regards to culpability for vehicle make only. The findings could have implications for the format and style of CGE used in legal settings.     

肢体挤压伤大鼠早期心电图及血清cTnI的变化

目的观察挤压伤大鼠早期心电图的改变,并检测血清心肌肌钙蛋白I(cTnI)的变化。方法复制挤压伤大鼠动物模型,标准Ⅱ导联记录心电图变化,化学发光法检测血清cTnI水平。结果挤压伤后心电图ST段明显抬高,并持续24h,伤后6h血清cTnI则显著升高,并持续24h以上。结论肢体挤压伤早期存在心肌细胞的损伤。     

Social harm future(s): exploring the potential of the social harm approach

The notion of social harm has sporadically interested critical criminologists as an alternative to the concept of crime. In particular, it has been viewed as a means to widen the rather narrow approach to harm that criminology offers. More recently, the publication of Beyond Criminology: Taking Harm Seriously has renewed interest in the notion of social harm. The book asserted a number of very valid reasons for a social harm approach that provoked a number of interesting critical responses. The article seeks to respond to five recurring questions: Should the social harm perspective move beyond criminology? If so, where should the perspective locate itself? From this position, how will the perspective continue to engage within ‘law and order’ debates and address the concerns of those affected by crime? If the notion of crime is problematic, how will the perspective form an alternative definition of harm? Moreover, without a notion of crime and the accompanying concept of criminal intent, how would the perspective allocate responsibility for harm? The article is not offering definitive answers to these questions, but possible directions for the perspective’s future development.     

Deviant identity,negative self-feelings,and decreases in deviant behavior: The moderating influence of conventional social bonding

Abstract

Informed by Kaplan's general theory of deviant behavior it was hypothesized that adolescents characterized by deviant identities who developed negative self-feelings would decrease deviant behavior over time if the youths were bonded to the conventional social order but not if the youths were not bonded to the conventional social order. For adolescents not characterized by deviant identities, the development of negative self-feelings would increase deviant behavior over time regardless of the level of conventional social bonding.

The hypotheses were explored using data from youth (n=1019) tested during early adolescence and re-tested 3 years later. Ordinary least square regression models estimated the effects of negative self-feelings on later deviant behaviors controlling for earlier deviant behavior, gender, race/ethnicity, and father's education. The model was estimated separately for each of four subgroups: deviant identity/high social bonding; deviant identity/low social bonding; non-deviant identity/high social bonding; and non-deviant identity/low social bonding.

As hypothesized, negative self-feelings anticipated significant decreases in deviant behavior for the deviant identity/high social bonding group, but were unrelated to deviant behavior in the deviant identity/low social bonding group; and negative self-feelings anticipated increased deviant behavior in the two non-deviant identity groups regardless of the level of social bonding.     

Experimental evaluation of rigor mortis IX. The influence of the breaking (mechanical solution) on the development of rigor mortis

In criminal proceedings involving illegally manufactured substances, evidence demonstrating the manufacture is required for successful prosecution. In many circumstances the presence of manufacturing equipment and 'recipes' are clear indicators. However establishing chemical links between starting materials and products would be beneficial additional evidence in such circumstances. Isotope analysis is becoming more commonly employed in disputes over authenticity and provenance of materials such as food stuffs or pharmaceuticals [S. Benson, C. Lennard, P. Maynard, C. Roux, Forensic applications of isotope ratio mass spectrometry--a review, Forensic Sci. Int., 157 (2006) 1-22]. We report here the results of an isotope study investigating a link between hexamine used as a starting material and the product explosive RDX, manufactured using the Woolwich process. Isotopic composition of hexamine and RDX was analysed by stable isotope ratio mass spectrometry. Five different hexamine samples were selected from a group of eleven for use in this study. One of the five hexamine samples was used twice, providing data on the reproducibility of the synthesis. Carbon and nitrogen isotope analysis of the hexamine starting material and RDX products reveals a reproducible relationship between reactant and product.