49 research outputs found
Easylift: A novel tape lifting system
This article describes a new adhesive-coated tape system for the recovery of trace evidence that is compatible with polarised light microscopy
APPARATUS AND METHODS FOR THE OPTICAL EXAMINATION OF BIREFRINGENT SPECIMIENS
A method for optically examining a birefringent specimen,
the method comprising the steps of collecting a specimen
using a substantially non-birefringent polymer film having an
adhesive surface, such that the specimen is attached to the
adhesive surface; and examining, between crossed polars, the
specimen attached to the said film. Also provided is a sub
stantially non-birefringent laminate film comprising: a first
birefringent polymer layer and a second birefringent polymer
layer, the first and second layers being mutually oriented such
that the birefringent properties of the two layers cancel each
other out; and an adhesive surface; wherein the adhesive
surface is an outer surface of the film, and/or is an exposable
surface between the first and second layers. A method of
manufacturing such a film is also provided
The trials and tribulations of designing and utilising MCQs in HE and for assessing forensic practitioner competency
Multiple Choice Questions (MCQs) are a very well known, traditional and accepted method of assessment. The use of MCQs for testing students has produced numerous debates amongst academics concerning their effectiveness as they are viewed as practical and efficient but also perceived as possibly „too easy‟ and potentially unable to appropriately test the higher order cognitive skills that essay questions can assess.The use of MCQs in a forensic science context is currently being investigated, not only for use within forensic science education, but also for the testing of competency of qualified forensic practitioners. This paper describes a Higher Education Academy funded project that is investigating the design and the implementation of MCQs for testing forensic practitioners and the lessons that have been learnt so far, that will assist academics in the development of robust MCQ assessments within forensic science degrees to promote and assess deep learning
Recovery and Analysis of Diazepam from Dried Blood Stains
This study aims to determine whether it is possible to detect diazepam in bloodstains dried on a glass
surface, to assess stability of diazepam in bloodstains over several days and lastly to determine whether dried bloodstains can give reliable quantitative information. One millilitre of blood fortified with different concentrations of diazepam (1, 5, 10, 50 μg/ml) was spotted on a glass surface and allowed to dry at room temperature. Liquid-liquid extraction (LLE) was completed and 100μL of internal standard (flurazepam) was added to the sample, vortexed and allowed to equilibrate for 15 min followed by the addition of 1ml of carbonate-bicarbonate buffer. Diazepam was extracted with 1ml of toluene: heptane (9:1, v/v) and centrifuged for 10min at 4500 rpm. The organic layer collected was analysed by gas chromatography mass spectrometry (GC/MS) using selective ion monitoring (SIM) mode.
The method was checked for linearity, limit of detection (LOD), limit of quantitation (LOQ), precision,
accuracy, extraction recovery and stability. Good linearity was obtained between 1-100 μg/ml (r2=0.9983) for diazepam in dried bloodstains. LOD and LOQ in bloodstains were 0.5-1 μg/ml and 1 μg/ml
respectively. Interday precision was 2-10% and accuracy ranged from -66.3% to -39.3%. A scatter plot showed results obtained from dried bloodstains and whole blood was comparable. However, stability study conducted on five days showed that diazepam was not stable in dried bloodstains since an apparent decrease in the measured concentration of diazepam was observed on each day. It was shown that
detection of diazepam in dried bloodstains was possible. Stability study showed that diazepam was not stable in dried bloodstains. Therefore, toxicological analysis of diazepam in bloodstains can assist the court based on qualitative information but not on quantitative information since measured concentration varied on different days. Toxicological analysis of dried bloodstains can be important for the police and lawyers since it can help to determine the chronology of events in a crime and helped the court to
reconstruct that crime. The new ideas raised in this study compared to other studies are: glass used as a substrate, diazepam drug, stability and recovery study were assessed on 5 days
An observational study using the Impact Point approach to measure the utility of digital forensic science in online child sexual exploitation cases
This executive summary provides an overview of both the Operation Safenet study and the Impact Point (IP) approach that it was designed to trial. It also gives the key findings and recommendations drawn from that study. These findings and recommendations comprise those which are specific to the use of digital forensic methods as employed in Operation Safenet and those which concern the use of the IP approach to inform management and policy more broadly
Aiding the interpretation of forensic gait analysis: Development of a features of gait database
In response to the letter dated 28th May 2017, the authors of the paper entitled ‘Aiding the Interpretation of Forensic Gait Analysis: Development of a Features of Gait Database’ which was published in volume 56, issue 6 in December 2016, would like to clarify a number of points and address the issues raised by the letter's signatories. The substantive content of the letter has been addressed section by section