The study of human factors in forensic science informs our understanding of the interaction between humans and the systems they use. The Expert Working Group (EWG) on Human Factors in Forensic DNA Interpretation used a systems approach to conduct a scientific assessment of the effects of human factors on forensic DNA interpretation with the goal of recommending approaches to improve practice and reduce the likelihood and consequence of errors. This effort resulted in 44 recommendations. The EWG designed many of these recommendations to improve the production, interpretation, evaluation, documentation, and communication of DNA comparison results.
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During crime scene investigations, numerous traces are secured and may be used as evidence for the evaluation of source and/or activity level propositions. The rapid chemical analysis of a biological trace enables the identification of body fluids and can provide significant donor profiling information, including age, sex, drug abuse, and lifestyle. Such information can be used to provide new leads, exclude from, or restrict the list of possible suspects during the investigative phase. This paper reviews the state-of-the-art labelling techniques to identify the most suitable visual enhancer to be implemented in a lateral flow immunoassay setup for the purpose of trace identification and/or donor profiling. Upon comparison, and with reference to the strengths and limitations of each label, the simplistic one-step analysis of noncompetitive lateral flow immunoassay (LFA) together with the implementation of carbon nanoparticles (CNPs) as visual enhancers is proposed for a sensitive, accurate, and reproducible in situ trace analysis. This approach is versatile and stable over different environmental conditions and external stimuli. The findings of the present comparative analysis may have important implications for future forensic practice. The selection of an appropriate enhancer is crucial for a well-designed LFA that can be implemented at the crime scene for a time- and cost-efficient investigation.
The age estimation of biological traces is one of the holy grails in forensic investigations. We developed a method for the age estimation of semen stains using fluorescence spectroscopy in conjunction with a stoichiometric ageing model. The model describes the degradation and generation rate of proteins and fluorescent oxidation products (FOX) over time. The previously used fluorimeter is a large benchtop device and requires system optimization for forensic applications. In situ applications have the advantage that measurements can be performed directly at the crime scene, without additional sampling or storage steps. Therefore, a portable fiber-based fluorimeter was developed, consisting of two optimized light-emitting diodes (LEDs) and two spectrometers to allow the fluorescence protein and FOX measurements. The handheld fiber can be used without touching the traces, avoiding the destruction or contamination of the trace. In this study, we have measured the ageing kinetics of semen stains over time using both our portable fluorimeter and a laboratory benchtop fluorimeter and compared their accuracies for the age estimation of semen stains. Successful age estimation was possible up to 11 days, with a mean absolute error of 1.0 days and 0.9 days for the portable and the benchtop fluorimeters, respectively. These results demonstrate the potential of using the portable fluorimeter for in situ applications.
Mixed reality is een techniek die het mogelijk maakt om met een speciale bril, zoals de Hololens van Microsoft, beelden en informatie in de brillenglazen te tonen die precies op de werkelijkheid passen en deze deels overlappen. De verwachting is dat deze techniek een krachtig hulpmiddel zal worden bij het organiseren van samenwerking op plaatsen waar veel plaats gebonden informatie moet worden gedeeld en gebruikt, zoals bij forensisch onderzoek. In het proces van opsporing en vervolging in de strafrechtketen, dat begint met een onderzoek van de plaats delict en via laboratorium en andere onderzoeken eindigt met de presentatie van alle onderzoeksresultaten in de rechtbank, wordt veel verwezen naar plaatsen en omstandigheden waarin sporen of bewijsmateriaal zijn gevonden. Hierbij wordt veel gebruik gemaakt van forensische visualisatie in vormen die variëren van tekeningen, fotoalbums, video-opnames, virtual reality tours tot en met interactieve 3-dimensionale computermodellen. In dit voorstel wordt onderzocht wat de rol van mixed reality kan worden in het onderzoek op een plaats delict, en in de opleiding en training van rechercheurs. De verwachting is dat de verworven inzichten ook bruikbaar zullen zijn in andere werkvelden waar regelmatig bijzondere situaties moeten worden onderzocht. Dit onderzoek zal worden uitgevoerd door het lectoraat Digital Forensics & E-discovery van Hogeschool Leiden in samenwerking met het Lectoraat/Onderzoeksprogramma Forensisch Onderzoek van de Hogeschool van Amsterdam en de Politieacademie.
