Verifying the speaker of a speech fragment can be crucial in attributing a crime to a suspect. The question can be addressed given disputed and reference speech material, adopting the recommended and scientifically accepted likelihood ratio framework for reporting evidential strength in court. In forensic practice, usually, auditory and acoustic analyses are performed to carry out such a verification task considering a diversity of features, such as language competence, pronunciation, or other linguistic features.
View Article and Find Full Text PDFLikelihood ratios (LRs) are a useful measure of evidential strength. In forensic casework consisting of a flow of cases with essentially the same question and the same analysis method, it is feasible to construct an 'LR system', that is, an automated procedure that has the observations as input and an LR as output. This paper is aimed at practitioners interested in building their own LR systems.
View Article and Find Full Text PDFComparative gunshot residue analysis addresses relevant forensic questions such as 'did suspect X fire shot Y?'. More formally, it weighs the evidence for hypotheses of the form H: gunshot residue particles found on suspect's hands are from the same source as the gunshot residue particles found on the crime scene and H: two sets of particles are from different sources. Currently, experts perform this analysis by evaluating the elemental composition of the particles using their knowledge and experience.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
April 2022
Mycotoxins, including zearalenone, are important natural products produced by fungi that occasionally contaminate agricultural commodities and pose serious health risks to consumers of food and feed. Zearalenone and its metabolite, α-zearalanol, are of significant concern due to their estrogenic and anabolic steroid activity. Several governments have regulatory standards and advisory guidelines for zearalenone and α-zearalanol.
View Article and Find Full Text PDFIn forensic investigations it is often of value to establish whether two phones were used by the same person during a given time period. We present a method that uses time and location of cell tower registrations of mobile phones to assess the strength of evidence that any pair of phones were used by the same person. The method is transparent as it uses logistic regression to discriminate between the hypotheses of same and different user, and a standard kernel density estimation to quantify the weight of evidence in terms of a likelihood ratio.
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