Inconclusives and error rates in forensic science: a signal detection theory approach

Law Probability and Risk, Journal Year: 2021, Volume and Issue: 20(3), P. 153 - 168

Published: Sept. 1, 2021

Abstract There are times when a forensic scientist may not be comfortable drawing firm conclusion about whether questioned sample that appears to contain useful identifying information did or come from particular known source. In such cases, the call pair ‘inconclusive’. We suggest signal detection theory (SDT), which is concerned with of weak signals in noisy environments, provides framework for understanding role inconclusives play various feature-matching sciences. SDT shows ‘inconclusive’ often an appropriate response depending on both strength samples and thresholds adopted by examiner. also argue should coded as either correct incorrect tabulating error rates.

Language: Английский

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Human Factors in Forensic Science

Oxford University Press eBooks, Journal Year: 2023, Volume and Issue: unknown, P. 621 - 642

Published: Feb. 23, 2023

Abstract Forensic science evidence has long been accepted in court and is widely considered infallible. However, the forensic sciences have recently come under intense scrutiny, as errors implicated an alarming number of wrongful convictions. In working to better understand prevent such errors, researchers discovered that they are often unfortunate by-product innate psychological processes. This chapter first reviews examiners, like all humans, vulnerable unconscious biases can lead erroneous judgments. Second, identifies barriers mitigating pernicious effects bias laboratories courtrooms, including widespread misconceptions about its causes effects. Third, proposed reforms offered strengthen science, with descriptions some progress already made regard.

Language: Английский

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Development of a competency test model to evaluate forensic identification officers on crime scene processing

Canadian Society of Forensic Science Journal, Journal Year: 2025, Volume and Issue: unknown, P. 1 - 10

Published: Feb. 3, 2025

Proficiency testing is required to ensure quality, efficiency, and safety in many disciplines. Multiple proficiency tests exist for forensic disciplines such as fingerprint analysis toxicology, but minimal research has been conducted on the of crime scene experts. The foundation an effective test rests upon development competency tests. Here, a proof-of-concept was designed example how evaluate processing skills identification officers (FIOs) using mock scenario. three main components: i) approach test, ii) evidence iii) general knowledge with pre-test demographic questions. content process reviewed by two experts (manuscript co-authors) viability. Due its digital format, this widely accessible, user-friendly, can be template police service develop their own or internal specialized tasks comparison estimation area origin bloodstain pattern (BPA) help mitigate risks identify gaps.

Language: Английский

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Blind testing in firearms: Preliminary results from a blind quality control program

Journal of Forensic Sciences, Journal Year: 2022, Volume and Issue: 67(3), P. 964 - 974

Published: March 29, 2022

Open proficiency tests meet accreditation requirements and measure examiner competence but may not represent actual casework. In December 2015, the Houston Forensic Science Center began a blind quality control program in firearms examination. Mock cases are created to mimic routine casework so that examiners unaware they being tested. Once case is assigned an examiner, evidence undergoes microscopic examination comparison determine whether fired submitted was same firearm. Fifty-one resulting 570 analysis determinations were reported between 2015 June 2021. No unsatisfactory results obtained; however, 40.3% of comparisons which ground truth either elimination or identification resulted inconclusive conclusions. Due some submitted, unexpected. A result observed at rate 74%, while 31%. Bullets (61.8%) main contributors conclusions; variables such as examiners, training program, experience, intended complexity did significantly contribute results. The demonstrates management system section procedures can obtain accurate reliable provides added confidence court. Additionally, be tailored target specific research questions provide opportunities for collaboration with other laboratories researchers.

Language: Английский

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Interpol review of fingermarks and other body impressions (2019 – 2022)

Forensic Science International Synergy, Journal Year: 2022, Volume and Issue: 6, P. 100304 - 100304

Published: Dec. 28, 2022

Language: Английский

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Human Factors in Forensic Science: Psychological Causes of Bias and Error

Published: Feb. 28, 2022

Forensic science evidence has long been accepted in court and is widely considered infallible. However, the forensic sciences have recently come under intense scrutiny, as errors implicated an alarming number of wrongful convictions. In working to better understand prevent such errors, researchers discovered that they are often unfortunate byproduct innate psychological processes. this chapter, we first review examiners, like all humans, vulnerable unconscious biases can lead erroneous judgments. Second, identify barriers mitigating pernicious effects bias laboratories courtrooms, including widespread misconceptions about its causes effects. Third, discuss proposed reforms strengthen science, describe some progress already made regard.

Language: Английский

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Assessing the Reliability of the Forensic Technique for the Identification Study of Motor Gasoline Using Gas-Liquid Chromatography

Inorganic Materials, Journal Year: 2024, Volume and Issue: unknown

Published: July 19, 2024

Language: Английский

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How signature complexity affects expert and lay ability to distinguish genuine, disguised and simulated signatures

Journal of Forensic Sciences, Journal Year: 2024, Volume and Issue: 69(6), P. 2159 - 2170

Published: Aug. 26, 2024

Abstract This study examined how variations in signature complexity affected the ability of forensic document examiners (FDEs) and laypeople to determine whether signatures are authentic or simulated (forged), as well they disguised. Forty‐five FDEs from nine countries evaluated different comparisons this online study. Receiver Operating Characteristic (ROC) analyses revealed that performed excess chance levels, but performance varied a function complexity: Sensitivity (the true‐positive rate) did not differ much between levels (i.e., 65% vs. 79% for low vs medium high complexity), specificity true‐negative was highest (95%) lowest (73%) signatures. The high‐complexity (83%) these values. sensitivity disguised only 11% vary across levels. One hundred‐one novices also completed A comparison area under ROC curve (AUCs) outperformed low‐complexity Novices struggled detect While findings elucidate role lay expert evaluations, error rates observed here may those practice due differences experimental stimuli circumstances which were evaluated. investigation evaluation process intended estimate practice.

Language: Английский

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Assessing the reliability of the forensic technique for the identification study of motor gasoline using gas-liquid chromatography

Industrial laboratory Diagnostics of materials, Journal Year: 2023, Volume and Issue: 89(12), P. 31 - 43

Published: Dec. 18, 2023

A new approach to solving the problems of forensic examination petroleum products, fuels and lubricants associated with establishing whether motor gasoline belongs a common/different identification set is proposed. methodology for using quantitative results chromatographic determination controlled parameters subsequent evaluation in pairwise compared samples according established criteria. The following were selected as indicators: values research octane number (RON), concentrations hydrocarbon groups (paraffins, isoparaffins, arenes, naphthenes, olefins) oxygenates. Their was carried out standardized methods. We used hardware software complex Chromatek-Crystal 5000 series, including Chromatek-DHA data processing program. Estimated criteria or decision- making rules regarding issues posed an expert determined classify under one product name (generic set), production technology (group set) common source origin (one batch, storage tank, etc.). reliability method assessed validation procedure consisted three stages. collection AI-92 gasoline, at gas stations four oil companies during six months 2022 various districts Moscow. At first stage, performer analyzed 12 aliquots each (samples that previously belonged volume) different times. It quality indicators proposed (standard deviation repeatability reproducibility, expanded uncertainty, limits reproducibility) did not exceed permissible errors by second stage experiment, combined test into from manufacturer technology) times (different batches). By comparing discrepancies measured same between pairs within discrepancy average groups, contractor identified gasolines manufactured technology; produced technology, but batches) and, probability 95%, having (previously belonging volume). conclusions study matched original on samples, which confirmed correctness developed comparison third (blind test), examined seven of, information about composition properties provided him. blind considered satisfactory. Thus, indicate suitability relation competence sufficient implementation methodology.

Language: Английский

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Error rates and proficiency tests in the fingerprint domain: A matter of perspective and conceptualization

Forensic Science International, Journal Year: 2023, Volume and Issue: 348, P. 111651 - 111651

Published: March 23, 2023

The purpose of this work is to critically analyse the aspects connected both with measurement error rates and design proficiency tests collaborative exercises in fingerprint domain. All from dual perspective practitioners organizers PT's/CE's. A thorough analysis types errors, methods infer them through black-box studies PT's/CE's carried out, limits generalization are described, providing insightful indication on how domain, which aimed represent complexity casework.

Language: Английский

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