Overall, 2008 was an average year for papers published in trace evidence. By far the majority of these papers were published by forensic science laboratories, or as a result of a collaboration between forensic science labs and other institutes. Considering the number of universities actively engaged in forensic science education globally, one could be forgiven for wondering what it is they are doing research in, whatever it is - it doesn't appear that trace evidence is high on their agenda - for whatever reason.
Starting first with fibres, Science and Justice published two papers on fibres this year, which is not bad for a journal that only publishes quarterly and with only a handful of scientific papers in each edition.
The first paper "Application of Raman Spectroscopy to forensic fibre cases" described the casework experience of one laboratory applying raman routinely in fibre cases. Five case studies were described and it was clear that the opinion of the authors were that using raman routinely in fibre cases was a valuable thing to do. However, on one crucial point the message as to precisely how the technique provided additional discrimination for mauve nylon fibres beyond MSP analysis was not clear, the reader can only speculate that the precise identification of the dye, and not merely the comparison of coloured fibres, is the source of the author's opinion that evidential value of the association was increased.
The practical advantages of raman as a laboratory technique are stated clearly, and recommendations as to how to get the best spectral data from fibres in difficult matrices are most welcome.
The second paper "The discrimination of (non denim) blue cotton", at first glance, appeared to be a repeat of work done by Biermann et al, which, somewhat bizarrely, was published in the same journal, in 2007 (The evidential value of blue and red cotton fibres, Science and Justice 47 (2) 2007). Biermann's study was a comprehensive treatment of the majority of the work done here, a fact acknowledged by the authors very early in the text. Most researchers in their career, have had experience of being beaten to the publishers desk by another research team, and this appears to be the case here.
The message given by Biermann's study, and also stated by this study, is so important that it cannot be voiced often enough or loudly enough. To put it simply, the evidential value of blue cotton can no longer be considered low merely by virtue of the fibre being blue and cotton. Perhaps for that reason alone, this study is very welcome.
To be fair to the authors, the paper does have two additional aims which distinguishes it from Biermann's study, that is the investigation into intra-garment variation of blue cotton garments and whether or not lessons learned from the process can be applied to alter the analysis schedule so as to make the process of examining blue cotton fibres more efficient. It is somewhat disappointing however, that such a small proportion of the study is devoted to the very aims that make the paper distinctive.
In relation to the intra-garment variation the authors quite rightly point out the difficulties in assessing this issue that are inherent with this fibre type and industry practice in general. These factors are widely known amongst the forensic fibre community yet they seem to come as a bit of a surprise to the authors.
In relation to the alternative analysis schedule, the motivation to change procedures for the sake of improving the efficiency of what is a time consuming and tedious process is to be highly commended. However, to those in the industry, the pathway proposed is somewhat odd, and it is not clear where the efficiency gains are likely to come from.
As the paper promotes the use of UV-VIS MSP, and assuming that this level of analysis is intended as the screen, the pathway appears to suggest mounting blue cotton fibres directly onto quartz slides and coverslips performing the analysis, re-mounting those fibres for microscopy, and then extracting the fibres for TLC at the end. The existence of a TLC step at the end is particularly bizarre as MSP is widely accepted as complementary to TLC and one wonders where TLC can add value to a process that is producing 0.99 DP. It's unclear whether this new process is the 'swing' or the 'roundabout' but either way, this proposed alternative pathway appears to offer little comfort.
The Journal of Forensic Sciences (JFS) had two fibre related papers for us this year.
The first paper "Selection of an Adhesive Tape Suitable for Forensic Fiber Sampling" described a laboratory's process for choosing a particular tape for recovering fibres. These types of study are necessary these days, particularly in response to accreditation requirements where laboratory consumables require to be validated prior to use. Tapings are a type of material used to harvest a wide range of evidence types and as such are of interest to Trace Evidence examiners, DNA analysts and others. All of whom have separate requirements for a tape that need to be accommodated somehow. This is not an easy task, as most tapes are not designed specifically with evidence recovery in mind. Each lab will have different requirements and the recommendations found here are unlikely to universally apply, however the criteria used to assess the tapes were sound and the best solution for this lab was found.
The second paper from JFS was entitled: "DNA Analysis of Natural Fiber Rope" and is a good example of the different approaches that academia and caseworking forensic scientists take to research and development. It is disappointing that the requirement of a skilled scientist to perform microscopy is highlighted as a disadvantage....particularly as the DNA department will need a microscopist to find the tiny recovered fibres, screen them and package them up for you. Tell you what, whilst we're there, we might as well identify them as rope fibres and save us all the hassle.
