A comprehensive review of the scientific literature on gunshot residue (GSR) is presented. Aspects of both inorganic and organic GSR are discussed, from formation and distribution, to sample collection, preparation, and analysis using a variety of techniques. The interpretation of GSR results is also considered including issues surrounding the contamination, distribution, and transfer of GSR. Potential problems with ulterior sources of GSR like particles have been reported in the literature. For example, particles from environmental and occupational sources have been highlighted as exhibiting similar chemical and morphological characteristics to GSR. These findings are put into context with regard to interpreting samples. A move toward a ''case by case'' approach is argued to be more preferable to a ''formal'' classification system where possible. The analysis of both inorganic and organic compositions of residue samples as well as morphological considerations is considered to be a more ideal approach to GSR analysis, whereever practicable.

There is growing public concern in Zimbabwe over the illegal cultivation of vegetables on soils amended with sewage sludge or irrigated with admixtures of sewage and sewage sludge. Excessive accumulation of heavy metals in agricultural soils may not only result in environmental contamination, but lead to elevated heavy metal uptake by crops, which may affect food quality and safety. The work reported here studied concentrations of Pb were 6.77 mg kg -1 , over 22 times the permissible levels allowed by both EU standards and UK guidelines (0.3 mg kg -1 ); Zn concentrations were 221 mg kg -1 , over 4 times the guideline value (50 mg kg -1 ). The other plants (beans, maize, peppers and sugarcane) also contained concentrations of heavy metals above the permissible levels. Furthermore the concentrations observed in this study were higher than those reported by other workers who have examined vegetation from other contaminated sites. This study highlights the potential risks involved in the cultivation and consumption of vegetables on plots irrigated with sewage sludge, a practice which may place at risk the health of the urban population who consume these vegetables.

No abstract

(J.W. Birkett). Highlights A list of 136 compounds associated with organic gunshot residue (OGSR) is presented  Recent developments in methods for the extraction and detection of OGSR are highlighted  Analytical techniques aiming to provide a full chemical profile are discussed  It is concluded that the optimal methodology for any OGSR sample should be based on a 'case-by-case' approach 2 Abstract A comprehensive review of the literature concerning all aspects of sampling and analytical techniques used for the determination of organic gunshot residue (OGSR) compounds is presented. Currently, 136 compounds associated with OGSR have been identified in the literature. Despite this area gaining increasing attention and recognition in recent years, there is still an absence of a set combination of sample collection, extraction and analysis methods that are universally optimal for the treatment of any given OGSR sample. Moreover, there are no generally accepted guidelines for selecting the compounds of interest that will inform sampling and analysis protocols. Recent developments in both extraction and analytical methods employed for their detection are highlighted. The main advantages and disadvantages of the sampling and analysis methods are critically discussed.

There are many different fingermark visualization techniques available, and the choice of methodology employed may be dependent on the surface type. This comprehensive review of the scientific literature evaluates the methodologies of fingermark enhancement methods that are applicable to metallic surfaces; optical, physical, chemical, and physicochemical methods are critically discussed. Methods that are currently used and those that have the potential to reduce the cost and time required to process evidence and increase the recovery rates are considered and are assessed against the Centre for Applied Science and Technology (CAST) and the International Fingerprint Research Group (IFRG) guidelines. The use of chemical imaging techniques in particular has increased the potential to recover fingermarks of sufficient quality for identification purposes. Presently, there appears to be a lack of detailed research pertaining to validation and thorough casework studies for fingermark enhancement techniques. Further studies incorporating these guidelines are recommended.KEYWORDS: forensic science, fingermarks, fingerprints, enhancement techniques, metallic surfaces, latent fingermarks Fingermarks are considered one of the most valuable types of physical evidence recovered from a crime scene. Fingermark casework is still the most common casework for forensic scientists despite the increase in use of DNA (1) to identify/exonerate suspects via bodily fluids (2). The ridge patterns found in fingermarks are permanent and can be used to individualize or exclude suspects from an investigation.Detection of fingermarks on metallic surfaces will be dependent upon the compounds remaining from the fingermark residue. Several detailed reviews have already been published on fingermark composition, but none have focused on fingermarks deposited on metallic surfaces (3,4).Generally, there are two types of fingermarks found at crime scenes: visible fingermarks, usually formed by fingers contaminated by a substance such as oil, fruit, grease, paint or blood, which are deposited on a surface; and latent fingermarks, which are invisible to the naked eye and are the most abundant type of fingermarks at crime scenes. Metallic surfaces are also commonly encountered in crime scenes and are ubiquitous in the environment. Surfaces such as the door of a car, objects like handles, weapons, and tools are usually made of steel. Cartridge cases are frequently recovered from crime scenes and are usually made of brass or nickel (5). There are a number of different techniques that can be applied to a surface to visualize latent fingermarks. The selection of a suitable technique depends on different factors, such as the expected composition of a fingermark, the ability of the chosen technique to be used in tandem with other techniques, and the nature of the substrate. In this review, the focus will be on fingermarks deposited on metallic surfaces, and the optical, physical, chemical, and physicochemical visualization techniques that can be used ...