Forensic metrology

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Forensic metrology is a branch of metrology (the science of measurements) applied to forensic sciences. Metrology has evolved various techniques for assessing the margin of error or uncertainty associated with measurements. [1] Forensic laboratories and criminalistic laboratories perform numerous measurements and tests to support criminal prosecution and civil legal actions. [2] [3] Examples of forensic metrology include the measurement of alcohol content in blood using breathalyzers, quantification of controlled substances (both net weights and purity), and length measurements of firearm barrels. The results of forensic measurements are used to determine if a person is charged with a crime or may be used to determine a statutory sentencing enhancement. Other examples of forensic metrology includes tests that measure if there is a presence of a substance (e.g., cocaine), latent print examination, questioned documents examination, and DNA analysis.

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Forensic measurements are all supported by reference standards which are traceable to the International System of Units (SI) maintained by the International Bureau of Weights and Measures, to natural constants, or to reference materials such as those provided by the United States' national metrology institute known as the National Institute of Standards and Technology in Gaithersburg, Maryland.

Examples of instruments and equipment used in forensic metrology include breathalyzers, weighing balances and scales, rulers, calipers, gas chromotographs, and centrifuges.

Recent attention has been given to forensic metrology and metrological traceability as a result of an international effort to accredit forensic laboratories and criminalistic laboratories to the International Organization for Standardization 17025 requirements.

Historical Development of Forensic Metrology

The historical development of forensic metrology spans centuries, evolving alongside advancements in science, technology, and forensic investigation techniques. [4] From its early beginnings in ancient civilizations where rudimentary measurement tools were used in legal proceedings [5] , forensic metrology gained momentum with the formalization of forensic science in the 19th century, emphasizing the importance of trace evidence. [6] Standardization efforts in the late 19th and early 20th centuries established consistent measurement standards through organizations like the International Bureau of Weights and Measures (BIPM). [4] The mid-20th century witnessed a revolution in instrumentation, with the development of precision instruments enabling more accurate measurements of trace evidence. [6] The digital revolution further propelled forensic metrology forward, with advancements in digital imaging and data analysis enhancing measurement accuracy and efficiency. [7] ISO standards, particularly ISO/IEC 17025, have provided guidelines for quality management systems, driving improvements in forensic measurement practices. [4] Increasing recognition of the interdisciplinary nature of forensic investigations has fostered collaboration between metrologists, forensic scientists, and legal experts, leading to specialized measurement techniques tailored to forensic casework challenges. [8] Looking ahead, ongoing advancements in technology, such as miniaturization and data analytics, are poised to shape the future of forensic metrology, expanding its capabilities and improving forensic analysis resolution and specificity. [7]

Applications of Forensic Metrology

Forensic metrology extends its applications beyond the realms of traditional forensic science disciplines, encompassing fields such as accident reconstruction, forensic toxicology, ballistics analysis, forensic anthropology, and toolmark examination. Accident reconstruction relies heavily on precise measurements to analyze vehicle dynamics, impact forces, and trajectories to determine the sequence of events leading to an accident. [9] In forensic toxicology, metrology plays a vital role in the accurate quantification of drugs, toxins, and other substances in biological samples, aiding in the determination of cause of death and drug-related fatalities. [10] Ballistics analysis involves the measurement of bullet trajectories, firearm characteristics, and tool mark impressions to link firearms to crime scenes and identify potential suspects. [11] Forensic anthropology utilizes metrological techniques such as osteometric measurements and 3D scanning to analyze skeletal remains, aiding in the identification of unknown individuals and the reconstruction of past events. [12] Additionally, toolmark examination involves precise measurements of tool impressions left at crime scenes to match tools to specific marks, providing valuable evidence in criminal investigations. [11] These diverse applications highlight the versatility and significance of forensic metrology in various forensic science disciplines.

Standards and Accreditation

Adherence to international standards, particularly ISO/IEC 17025, is paramount in ensuring the reliability and accuracy of measurements conducted in forensic laboratories. Accreditation to these standards serves as a quality assurance mechanism, guaranteeing that laboratories operate according to recognized best practices and meet stringent criteria for competency and proficiency. [13] ISO/IEC 17025 establishes requirements for the competence of testing and calibration laboratories, encompassing factors such as personnel qualifications, equipment calibration, quality control procedures, and documentation practices. [14] By adhering to these standards, forensic laboratories demonstrate their commitment to quality and reliability, instilling confidence in the accuracy and integrity of the measurements they produce. Accreditation to ISO/IEC 17025 not only enhances the credibility of forensic metrology practices but also facilitates international recognition and acceptance of forensic evidence in legal proceedings. [13] Moreover, adherence to these standards promotes consistency and comparability of measurements across laboratories, facilitating collaboration and data sharing within the forensic science community. [13] Accreditation to international standards such as ISO/IEC 17025 plays a crucial role in ensuring the trustworthiness and effectiveness of forensic metrology practices, ultimately contributing to the pursuit of justice and truth in legal proceedings.

Quality Assurance Measures

Quality assurance measures are essential in forensic metrology laboratories to uphold the integrity of measurements and mitigate the risk of errors or inaccuracies. Instrument calibration is a fundamental aspect of quality assurance, ensuring that measurement devices are accurate and reliable by comparing their readings to known reference standards. [15] Proficiency testing is another crucial component, laboratories participate in external proficiency testing programs to assess their measurement capabilities and identify areas for improvement. [16] Additionally, validation of measurement methods is conducted to verify the accuracy, precision, and reliability of analytical procedures, ensuring that they meet specified performance criteria and are suitable for their intended forensic applications. [17] These quality assurance measures collectively contribute to the robustness and reliability of forensic metrology practices, instilling confidence in the accuracy and validity of measurement results.

Forensic metrologists encounter various challenges, including the demand for enhanced methods to analyze complex samples and novel types of evidence. Analyzing complex samples, such as mixtures containing multiple substances or degraded materials, presents difficulties in accurately identifying and quantifying individual components. [18] Moreover, the emergence of novel types of evidence, such as digital and multimedia data, requires innovative approaches to measurement and analysis to ensure their admissibility and reliability in forensic investigations. [19] In response to these challenges, emerging trends in forensic metrology involve the integration of advanced technologies, particularly machine learning and artificial intelligence, into measurement analysis. Machine learning algorithms can facilitate the interpretation of complex data sets, enabling automated pattern recognition and decision-making in forensic metrology applications. [20] Artificial intelligence techniques, such as neural networks and deep learning, offer opportunities to improve the accuracy and efficiency of forensic measurements, particularly in fields like image analysis and pattern matching. [21] By harnessing these advanced technologies, forensic metrologists can overcome challenges and enhance the effectiveness of measurement analysis in forensic science.

Interdisciplinary Approaches

The interdisciplinary nature of forensic metrology highlights the importance of collaboration between metrologists, forensic scientists, law enforcement agencies, and other stakeholders in the criminal justice system. By bringing together expertise from diverse fields, such as metrology, chemistry, biology, and criminalistics, interdisciplinary approaches enhance the reliability and validity of forensic measurements. Metrologists provide expertise in measurement science, ensuring that forensic measurements adhere to established standards and principles of accuracy and precision. [22] Forensic scientists contribute specialized knowledge in the analysis of forensic evidence, interpreting measurement data to extract meaningful forensic information. [23] Law enforcement agencies play a crucial role in collecting and preserving evidence, providing context and relevance to forensic measurements within the criminal investigation process. [24] Collaboration among these stakeholders facilitates the integration of complementary skills and perspectives, fostering comprehensive and robust forensic analyses that withstand scrutiny in legal proceedings. [25] Interdisciplinary collaboration promotes innovation and advances in forensic metrology, driving improvements in measurement techniques, instrumentation, and data analysis methodologies. [26] By working together, meteorologists, forensic scientists, and other stakeholders contribute to the advancement of forensic science and the pursuit of justice.

Ethical Considerations

Ethical considerations are predominant in forensic metrology, emphasizing the importance of impartiality, objectivity, transparency, and respect for individual rights throughout the measurement process. Impartiality and objectivity ensure that forensic metrologists conduct measurements without bias or undue influence, adhering strictly to scientific principles and methodologies. [27] Transparency in reporting results is essential for maintaining the integrity of forensic measurements, allowing stakeholders to understand the methods employed and assess the reliability of the findings. [28] Moreover, safeguarding the privacy and rights of individuals involved in forensic investigations is critical, ensuring that measurement data are collected and used ethically and responsibly. [29] By upholding these ethical principles, forensic metrologists uphold the trust and integrity of the forensic science community, promoting fairness, accuracy, and accountability in the pursuit of justice.

See also

Related Research Articles

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In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, a device generating the quantity to be measured such as a voltage, a sound tone, or a physical artifact, such as a meter ruler.

<span class="mw-page-title-main">Metrology</span> Science of measurement and its application

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<span class="mw-page-title-main">Hair analysis</span> Chemical analysis of a hair sample

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<span class="mw-page-title-main">International Organization of Legal Metrology</span>

The International Organization of Legal Metrology, is an intergovernmental organisation that was created in 1955 to promote the global harmonisation of the legal metrology procedures that underpin and facilitate international trade.

Accreditation is the independent, third-party evaluation of a conformity assessment body against recognised standards, conveying formal demonstration of its impartiality and competence to carry out specific conformity assessment tasks.

ISO/IEC 17025General requirements for the competence of testing and calibration laboratories is the main standard used by testing and calibration laboratories. In most countries, ISO/IEC 17025 is the standard for which most labs must hold accreditation in order to be deemed technically competent. In many cases, suppliers and regulatory authorities will not accept test or calibration results from a lab that is not accredited. Originally known as ISO/IEC Guide 25, ISO/IEC 17025 was initially issued by ISO/IEC in 1999. There are many commonalities with the ISO 9000 standard, but ISO/IEC 17025 is more specific in requirements for competence and applies directly to those organizations that produce testing and calibration results and is based on more technical principles. Laboratories use ISO/IEC 17025 to implement a quality system aimed at improving their ability to consistently produce valid results. Material in the standard also forms the basis for accreditation from an accreditation body.

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ISO 15189 Medical laboratories — Requirements for quality and competence is an international standard that specifies the quality management system requirements particular to medical laboratories. The standard was developed by the International Organisation for Standardization's Technical Committee 212. ISO/TC 212 assigned ISO 15189 to a working group to prepare the standard based on the details of ISO/IEC 17025:1999 General requirements for the competence of testing and calibration laboratories. This working group included provision of advice to medical laboratory users, including specifics on the collection of patient samples, the interpretation of test results, acceptable turnaround times, how testing is to be provided in a medical emergency, and the lab's role in the education and training of health care staff. While the standard is based on ISO/IEC 17025 and ISO 9001, it is a unique document that takes into consideration the specific requirements of the medical environment and the importance of the medical laboratory to patient care.

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Certified reference materials (CRMs) are 'controls' or standards used to check the quality and metrological traceability of products, to validate analytical measurement methods, or for the calibration of instruments. A certified reference material is a particular form of measurement standard.

A test method is a method for a test in science or engineering, such as a physical test, chemical test, or statistical test. It is a definitive procedure that produces a test result. In order to ensure accurate and relevant test results, a test method should be "explicit, unambiguous, and experimentally feasible.", as well as effective and reproducible.

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<span class="mw-page-title-main">Cerilliant Corporation</span>

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<span class="mw-page-title-main">National Accreditation Board for Testing and Calibration Laboratories</span> Indian accreditation organisation

National Accreditation Board for Testing and Calibration Laboratories (NABL) provides accreditation to Conformity Assessment Bodies (Laboratories) in India. NABL Schemes include Accreditation (Recognition) of Technical competence of testing, calibration, medical testing laboratories, Proficiency testing providers (PTP) & Reference Material Producers (RMP) for a specific scope following ISO/IEC 17025, ISO 15189, ISO/IEC 17043 & ISO 17034:2016 Standards. It has Mutual Recognition Arrangement (MRA) with Asia Pacific Accreditation Cooperation (APAC), International Laboratory Accreditation Cooperation (ILAC).

<span class="mw-page-title-main">HCT Co., Ltd.</span>

HCT Co., Ltd. is a South Korean compliance testing and equipment calibration company that also develops particle counters and antennas. Founded in 2000 as Hyundai Calibration & Certification Technologies Co., the company is a spin-off from Hyundai Electronics, the world's second-largest memory chipmaker. HCT has testing and calibration sites in Korea, the United States, and China.

<span class="mw-page-title-main">Runningland</span>

Founded in 2009, "Runningland Metrology & Testing (Shanghai) Co., Ltd" is a Shanghai-based accredited third party laboratory that specializes in instruments metering, condition monitoring, calibration and testing petrochemical products. The company was founded by David Zhou, who is an active member of STLE ASTM D2 Committee, and SAE, and co-founded by Ti Zhou who is a member of Shanghai Lubrication Trade Association. As a commercial third party laboratory, the organization also collaborates with educational institutions and research associations across China. Oil analysis is still a relatively developing idea and has become an increasingly important concept in The People's Republic of China. Because the oil analysis market in China is growing, Runningland has developed a lab that specializes in grease testing. In 2015, STLE has published a report indicating its previous activities and plans to expand into the China market by organizing the China Advisory Council, which consists of 15 prominent members of China's lubrication industry including David Zhou, Chairman and Co-founder of Runningland.

The Joint Committee for Guides in Metrology (JCGM) is an organization in Sèvres that prepared the Guide to the Expression of Uncertainty in Measurement (GUM) and the International Vocabulary of Metrology (VIM). The JCGM assumed responsibility for these two documents from the ISO Technical Advisory Group 4 (TAG4).

The National Association of Testing Authorities (NATA) is the recognised national accreditation authority for analytical laboratories and testing service providers in Australia. It is an independent, not-for-profit organisation, governed by a board of directors that has representation from NATA members, industry, government and professional bodies.

<span class="mw-page-title-main">VAMAS</span> Collaborative project

VAMAS stands for Versailles Project on Advanced Materials and Standards. It is a collaborative project that was initiated at the 1982 G7 Economic Summit in Versailles to develop and promote standards for the characterisation of advanced materials, including surfaces, interfaces, thin films, and nanostructures. Using interlaboratory studies, the VAMAS project has developed a number of standard test methods and reference materials for a wide range of materials. These standards have been widely adopted by industry and academic researchers, and have contributed to the development of new materials and technologies.

References

  1. ↑ Spagnolo, Giuseppe, Schirripa; Papalillo, Donato; Cozzella, Lorenzo; Leccese, Fabio (September 15–17, 2014). "Forensic Metrology Uncertainty of Measurements in Forensic Analysis" (PDF). In Proc. Of 20th IMEKO TC-4 International Symposium Measurement of Electrical Quantities.{{cite journal}}: CS1 maint: date format (link) CS1 maint: multiple names: authors list (link)
  2. ↑ VOSK, TED. EMERY, ASHLEY F (2021). FORENSIC METROLOGY: scientific measurement and inference for lawyers, judges, and criminalists. S.l.: CRC PRESS. ISBN   978-0-367-77847-7. OCLC   1227271351.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. ↑ FERRERO, ALESSANDRO; SCOTTI, VERONICA (2022). Forensic Metrology. An Introduction to the Fundamentals of Metrology for Judges, Lawyers and Forensic Scientits. Springer Cham. pp. XII, 206. doi:10.1007/978-3-031-14619-0. ISBN   978-3-031-14618-3.
  4. 1 2 3 Vosk, Ted; Emery, Ashley F (2014). Forensic Metrology: Scientific Measurement and Inference for Lawyers, Judges, and Criminalists (1st ed.). Boca Raton: CRC Press. ISBN   9780429246210.
  5. ↑ Locard, Edmond (1912). "Laboratoire de police et Instruction criminelle". Bulletin de la Société d'anthropologie de Lyon. 31 (1): 127–164. doi:10.3406/linly.1912.12670. ISSN   1160-641X.
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  9. ↑ Fernandes, Fábio A. O.; Alves de Sousa, Ricardo J.; Ptak, Mariusz (2018), "Application of Numerical Methods for Accident Reconstruction and Forensic Analysis", Head Injury Simulation in Road Traffic Accidents, Cham: Springer International Publishing, pp. 59–98, doi:10.1007/978-3-319-89926-8_4, ISBN   978-3-319-89925-1 , retrieved 2024-04-17
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  18. ↑ de Campos, Eduardo Geraldo; da Costa, Bruno Ruiz Brandão; dos Santos, Fabiana Spineti; Monedeiro, Fernanda; Alves, Marcela Nogueira Rabelo; Santos Junior, Wilson José Ramos; De Martinis, Bruno Spinosa (2021-08-19). "Alternative matrices in forensic toxicology: a critical review". Forensic Toxicology. 40 (1): 1–18. doi:10.1007/s11419-021-00596-5. ISSN   1860-8965. PMC   9715501 . PMID   36454488.
  19. ↑ "Digital Evidence and Forensics | National Institute of Justice". nij.ojp.gov. Retrieved 2024-04-17.
  20. ↑ Gruber, B.; Weggler, B.A.; Jaramillo, R.; Murrell, K.A.; Piotrowski, P.K.; Dorman, F.L. (2018). "Comprehensive two-dimensional gas chromatography in forensic science: A critical review of recent trends". TrAC Trends in Analytical Chemistry. 105: 292–301. doi:10.1016/j.trac.2018.05.017. ISSN   0165-9936.
  21. ↑ Piraianu, Alin-Ionut; Fulga, Ana; Musat, Carmina Liana; Ciobotaru, Oana-Roxana; Poalelungi, Diana Gina; Stamate, Elena; Ciobotaru, Octavian; Fulga, Iuliu (2023-09-19). "Enhancing the Evidence with Algorithms: How Artificial Intelligence Is Transforming Forensic Medicine". Diagnostics. 13 (18): 2992. doi: 10.3390/diagnostics13182992 . ISSN   2075-4418. PMC   10529115 . PMID   37761359.
  22. ↑ Aitken, Colin G.G.; Taroni, Franco (2004). "Statistics and the Evaluation of Evidence for Forensic Scientists" (PDF). John Wiley & Sons.
  23. ↑ Wilson-Wilde, Linzi (2018). "The international development of forensic science standards — A review". Forensic Science International. 288: 1–9. doi:10.1016/j.forsciint.2018.04.009. ISSN   0379-0738. PMID   29705583.
  24. ↑ "The Role and Impact of Forensic Evidence in the Criminal Justice System". Indian Journal of Forensic Medicine & Toxicology. 15 (1). 2021. doi:10.37506/ijfmt.v15i1.17794. ISSN   0973-9122.
  25. ↑ Saks, Michael J.; Koehler, Jonathan J. (2005-08-05). "The Coming Paradigm Shift in Forensic Identification Science". Science. 309 (5736): 892–895. Bibcode:2005Sci...309..892S. doi:10.1126/science.1111565. ISSN   0036-8075. PMID   16081727.
  26. ↑ Vosk, Ted (2014). Forensic Metrology A Primer for Lawyers and Judges (2nd ed.). CRC/Taylor Francis.
  27. ↑ Council, National Research (2009-07-01). "Strengthening Forensic Science in the United States: A Path Forward". CrimRxiv. doi:10.21428/cb6ab371.b2d683d2.
  28. ↑ Saks, Michael J.; Koehler, Jonathan J. (2005-08-05). "The Coming Paradigm Shift in Forensic Identification Science". Science. 309 (5736): 892–895. Bibcode:2005Sci...309..892S. doi:10.1126/science.1111565. ISSN   0036-8075. PMID   16081727.
  29. ↑ Yadav, Praveen Kumar (2017). "Ethical issues across different fields of forensic science". Egyptian Journal of Forensic Sciences. 7 (1): 10. doi: 10.1186/s41935-017-0010-1 . ISSN   2090-5939. PMC   5514178 . PMID   28775903.
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