Using Gun Blue to Enhance Fingermark Ridge Detail on Ballistic Brass

Brass cartridge cases are the most common type of cartridge case found at crime scenes, but it is not always feasible to obtain identifiable fingermarks on these cartridges. This study evaluates the effectiveness of gun blue as an enhancement method on fingermarks that were deposited on brass metal discs and left to age (2, 7, 14, and 30 days) under different environmental conditions, namely, under dark conditions, under ambient light, and outdoors. Ten different donors (5 males, 5 females) were employed for this study, and their fingermarks (60 per donor) were enhanced with gun blue solution (50% v/v). It was possible to enhance aged fingermarks (natural and groomed) that had been deposited on the brass metal discs to an identifiable level, with the fingermarks left outdoors being the most challenging to enhance. The feasibility of enhancing fingermarks on fired brass cartridges shot from different firearms was also assessed. Despite favorable results being achieved on fired brass cartridge cases, more research is required to assess whether reliable enhancement can be achieved on fired cartridge cases under real crime scene conditions

The fate and behaviour of gunshot residue: recreational shooter distribution

Despite continued improvements in gunshot residue (GSR) detection and analysis, there are still challenges in the interpretation of GSR evidence. The level and distribution of GSR present on an individual can be influenced by many factors, dependent upon the context of any given case. Due and diligent attention must therefore be placed upon fate and behaviour processes in relation to GSR when assessing and interpreting any case findings. The distribution of GSR upon the body of a recreational shooter was assessed. Samples were taken from 17 positions across a shooter’s body immediately after the discharge of one round of ammunition. The shooting hand prevailed as the most GSR-contaminated area, with as many as 351 characteristic GSR particles identified. The face and supporting hand also exhibited high levels of GSR contamination. This level of contamination raises questions concerning the fate and behaviour of GSR particles within the general environment, specifically with regard to transfer processes

Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry

An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe

Novel pheromone-mediated reproductive behaviour in the stag beetle, Lucanus cervus

The iconic European stag beetle (Lucanus cervus) (Coleoptera: Lucanidae) is one of the largest terrestrial beetles in Europe. Due to decreasing population numbers, thought to be a consequence of habitat loss, this beetle has become a near-threatened species across much of Europe, and a reliable monitoring system is required to measure its future population trends. As part of a programme aimed at conserving UK populations, we have investigated the chemical ecology of the beetle, with a view to developing an efficient semiochemical-based monitoring system. Such a scheme will be beneficial not only in the UK but across the European range of the species, where the beetle is of conservation concern. Here, we report on a surprising discovery of a male-produced pheromone, which provokes initial sexual receptivity in females, and which has not been previously identified in the animal kingdom. Furthermore, we assign sex pheromone function to a previously described female-specific compound

A preliminary evaluation of the use of gun bluing to enhance friction ridge detail on cartridge casings

Friction ridge detail was enhanced on fired and unfired 9mm brass luger ammunition casings using three techniques, two involving Gun Blue reagent at a concentration of 50% v/v. Fingermarks were deposited on a total number of 90 ammunition casings and half were discharged using a Glock 19 semiautomatic pistol. Mark development was achieved using either Superglue Fuming followed by Basic Yellow 40 Fluorescent Dye Staining (SG-BY40), Superglue Fuming followed by Gun Blue (SG-GB), or Gun Blue (GB) as a single process. All three processes developed ridge detail on both fired and unfired casings. The results of this preliminary work show that the use of Gun Blue as a single enhancement technique was able to enhance ridge detail of the highest quality and clarity particularly on fired casings, making it the most effective process

A Preliminary Study on Vacuum Metal Deposition as a Standalone Method for Enhancement of Fingermarks on Ballistic Brass Materials

In order to assess the efficacy of vacuum metal deposition (VMD) as a technique to develop fingermarks on ballistic metallic surfaces, a preliminary study using six donors (three male & three female) was conducted. Using a sequential metal deposition process, two metal combinations were studied—gold/zinc and silver/zinc. Results indicate the potential of this technique, by developing identifiable fingermarks on brass metal disks aged from a few days up to more than a month old. As the development of fingermarks on fired (brass) cartridge cases is an area of interest, a further study was conducted where a total of 20 fingermarks were deposited on cases. After firing, second level fingermark characteristics were successfully observed on cartridge cases highlighting its potential as a fingermark enhancement method for ballistic brass materials. Further work is required to fully evaluate the VMD process and its reliability as a fingermark enhancing method on ballistic surfaces

Organic compositional analysis of propellant powders using monolithic material sorption extraction (MSSE)-a feasibility study

The application of monolithic material sorption extraction, specifically MonoTrapTM, to the extraction of organic gunshot residue (OGSR) compounds from unburnt propellant powders is described. Four different MonoTraps were assessed for their capability to extract OGSR compounds from two different ammunition types. Extracts were analysed using gas chromatography-mass spectrometry. Results indicated that the carbon disc was suitable for the extraction of OGSR compounds from unburnt propellant powders. Quantities for major compounds were comparable to methanol extractions. The method was successfully used to detect a wide range of OGSR compounds, including nitrotoluenes, nitroglycerin, diphenylamines and centralites and is expected to be applicable to a wide range of ammunition types

Injection port silylation of γ-hydroxybutyrate and trans-hydroxycrotonic acid: Conditions optimisation and characterisation of the di-tert-butyldimethylsilyl derivatives by GC-MS

Silylation is usually carried out on γ-hydroxybutyrate (GHB) for its analysis by Gas Chromatography/Mass Spectrometry (GCMS) and requires potentially long incubation times before injection during which the derivatisation reagent and derivatives (such as trimethyl-silyl compounds) can hydrolyse. Moreover, alternative internal standards (IS) are often useful depending on sample matrices, extraction/purification procedures, commercial availability and price. This study evaluated the possibility of silylating GHB with an injection port derivatisation procedure using N-methyl-N-[tert-butyldimethyl-silyl]trifluoroacetimide (MTBSTFA) with 1% tert-butyldimethylchlorosilane (TBCS) as the derivatisation reagent, producing di-tert-butyldimethyl-silyl derivatives as a novel means of analyzing GHB. In parallel, trans-hydroxycrotonic acid (t-HCA) was investigated as a potential IS for GHB quantification. Analyses were carried out with a temperature programmable injector and the GHB(t-BDMS)(2) and t-HCA(t-BDMS)(2) derivatives were successfully produced, characterised and derivatisation conditions optimised. t-HCA behaved very similarly to GHB through the derivatisation processes and was used as the IS for the determination of urinary endogenous GHB concentrations in human subjects where the method showed a limit of detection of 0.049 μg mL(-1), a limit of quantification of 0.162 μg mL(-1), and a limit of confirmation of 1.33 μg mL(-1), suitable for toxicological GHB concentration determination

Review of analytical techniques for arson residues

Arson is a serious crime that affects society through cost, property damage, and loss of life. It is important that the methods and technologies applied by fire investigators in detection of evidence and subsequent analyses have a high degree of reliability, sensitivity, and be subject to rigorous quality control and assurance. There have been considerable advances in the field of arson investigation since the 1950s. Classification of ignitable liquids has been updated to include many new categories due to developments in the petroleum industry. Techniques such as steam or vacuum distillation and gas chromatography (GC) with flame ionization detection that may have been considered acceptable—even a benchmark—40 years ago, are nowadays generally disfavored, to the extent that their implementation may almost be considered as ignorance in the field. The advent of readily available mass spectrometric techniques has revolutionized the field of fire debris analysis, increasing the degree of sensitivity and discrimination possible considerably. Multi-dimensional GC—particularly GC × GC—while not yet widely applied, is rapidly gaining recognition as an important technique. This comprehensive review focuses on techniques and practices used in fire investigation, from scene investigation to analysis