Forensic Science for Legal Professionals LV30001 PDF
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This document provides a brief overview of forensic science, covering its history, principles, and methodologies. It explores different types of evidence, such as trace evidence, feature comparison, and biological evidence, and discusses the role of forensic science in legal proceedings. It also touches upon the concept of the scientific method and its application in analyzing evidence.
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horizontal line [Forensic Science] Forensic science is a general 'umbrella' term - there is no single 'forensic science' - instead it includes specialiams and sub-specialisms. - - - - - - - [Brief History of Forensic Science] - - - - In the first century AD the juri...
horizontal line [Forensic Science] Forensic science is a general 'umbrella' term - there is no single 'forensic science' - instead it includes specialiams and sub-specialisms. - - - - - - - [Brief History of Forensic Science] - - - - In the first century AD the jurist and orator Quintilian demonstrated a bloody handprint had been left as a frame-thereby proving a man innocent - - - - - - 1248 Century China-the first pathology text was written-'Hsi Duan Yu'-translates as 'The Washing Away of Wrongs' 1235 - Sun Tzu and the bloody sickle demonstrated an understanding of the behavior of flies in relation to blood-first successful use of entomology in modern court-18 th century France - - - - - The Enlightenment in the 17th Century saw the real rise in scientific advances - start date of forensic science 1880 Henry Faulds wrote a paper which suggested fingerprints at a scene can identify a perpetrator-long history after this. 1900s Victor Balthazard -- medical examiner in Paris. Worked on the use of firearms, fingerprints and hair analysis in investigations. - came up with statisitcs of fingerprints matching Alphonse Bertillon -- Developed anthropometry as a way of identification of suspects -- the use of body measurements and photographs of individuals - basics of biometrics, idea that peopls anatomy can differ from person to person [Can we define forensic science?] 'Forensic science utilises scientific techniques and methodologies to reconstruct events of legal relevance from physical evidence and relevant information.' - good definition Evidence that can be analysed includes the human body, behaviour, materials, substances, digital traces and artefacts. -anything we can identify and use to recreate events from the past Essentially forensic science uses the information available at a 'scene' to try and recreate events from the past using scientific methods [Scientific Method] When we refer to the scientific method 1. 2. 3. 4. However: Forensic Science does not start with the hypothesis formation but with data, that is the evidence and information gathered -- these are examined and relationships between them identified and then the 'hypothesis' is formed. [Forensic science MAY answer the questions:] Who, what, where, when, how and why? Not all these questions will be answered by one single type of forensic evidence and-- especially in large investigations where there will be various methods used to give a bigger picture What questions will need to be answered will vary from investigation to investigation What can be answered will vary from situation to situation -- for example in the case of a domestic murder -- DNA may not be of assistance if it took place in the home. [Locard's exchange principle] Much of the development of the use of forensic science is based on the idea put forward by Dr Edmond Locard (b1877) Advocated the use of scientific methodology to crime scene analysis \"It is impossible for a criminal to act, especially considering the intensity of a crime, without leaving traces of this presence." This has been shortened to 'Every contact leaves a trace' This has been demonstrated to have some basis in truth but is simplistic and not always tru [Different types of evidence] **Trace Evidence** A lot of the evidence that is collected falls into this category Includes: paint, fibres, glass fragments, hair, soil, explosive residue **Feature comparison evidence** Includes: tool marks, footwear marks, fingerprints **Digital Evidence** is evidence that is recovered from digital devices such as mobile phones and computers Includes: photos, videos, cell site analysis, emails, texts **Biological evidence** Includes: DNA which can be gathered from blood, saliva, skin cells and hair [Where?] ![](media/image6.png) Scientists present info to jury Forensic strategy meeting - ran by procurator fiscal and senior police officer discuss what want and bring to scene; Work out order to collect evidence Lab work - can take some time for some things to be explored ![](media/image4.png) Identify what has been recovered Questioned sample - what was found compared to reference samples Question sample compared to reference of known origin of reference sample for chemical compound E.g powder found compared to ref sample to see if it is drugs or not Sometimes may not have a ref sample of a suspect There are dna databases however not everyone is on the database [Forensic Science Methodologies] (falls into quantitative and subjective analysis) Methodologies employed can be separated into two broad types - These include DNA, forensic toxicology etc Analytical techniques require the use of quantitative measurements and pre-existing databases for quantifying evidence. These techniques are employed in relation to evidence types such as DNA and drug quantification. Analysis of a white powder for example will allow the scientist to identify the chemical components that are contained within the powder. Forensic drug chemists will use reference standards (samples of known provenance) analysed alongside the questioned sample to confirm this identity. Where no reference standards are available for example when a new drug is encountered the drug may only be tentatively identified. Identification of body fluids for a DNA profile on the other hand is only the start of the analysis. Once a DNA profile is extracted, it is then necessary to then compare this profile with reference samples from known individuals to try and establish an identification, this is where statistics will assist. - These include fingerprint analysis, footwear marks, ballistics These techniques involve comparing common features between questioned and reference material (samples of known provenance) to establish the degree of similarity. In most cases, feature comparison techniques do not involve any well-defined pre-existing quantitative measurements (determining the amount or concentration of material present) but rather, analysis is carried out qualitatively (determining what might be present rather than how much may be present) based on past experience, expert judgement and opinion of the expert undertaking the comparison. [Subjective and Objective Analysis] It can be argued that methods such as feature comparison techniques are more subjective. Subjective evaluation of evidence is where analysis is carried out based on an expert's own experience, competency, training and study of specialist field. Expert's opinions and judgement play a key role in the decision-making process. Due to the subjective nature of the decisions process, it may be difficult to establish the validity and the reliability of conclusions drawn, however, subjective analysis may be crucial in gaining initial insight and understanding into the evidence. Lab based analytical techniques, such as those involved in testing how much alcohol is present in a blood sample is more objective. Objectivity on the other hand is where evidence evaluation is based on observable and measurable data. Personal feelings, emotions and convictions are ignored and conclusions are drawn solely based on insight informed by rigorous analysis of data. With most forensic methodology under increasing pressure of scrutiny for reliability and validity, objectivity is encouraged and desired. Objectivity may however not be feasible for some forensic evidence types whereby their very nature, experts' need to demonstrate that the subjective analysis is unbiased and deduced conclusions follow a structured methodology. Objectivity has more weight in terms of preference of methodology used however subjective does not make any less as a use of evidence [Forensic Science as Evidence] For acceptance in court Scientifically valid - understand its precision and error rates Applciation is valid - standard methods that are fit for purpose -competent practitioners [Forensic Science as Evidence] - - - - - 'The credibility of the criminal justice system depends on the quality of the science underpinning the forensic evidence, in order to preserve confidence in the experts and the evidence they present'. - '\....Some field of forensic expertise are built on nothing but guesswork... false common sense... and in some cases no better than witchcraft'. - [Miscarriages of Justice] There have been a number of high profile miscarriages of justice across the world In the UK (R v Dallagher 2002 EWCA Crim 1903; R. v. Sally Clark \[2003\] EWCA Crim 1020; R. v McIlkenny (Richard)R. V Hill (Patrick), R. v Power (William), R. v Walker (John), R. v Hunter (Robert Gerard), R. v Callaghan (Hugh) \| \[1992\] 2 All E.R. 417 \| \[1991\] 3 WLUK 428) - - - - [Causes of Miscarriages of Justice] - - - - - - **Unreliable forensic science-49% of all Innocence cases** - - - - - [Junk Science 1992 - read into] In reality there have always been issues with 'opinion' evidence. 1992-Galileo's revenge: Junk science in the courtroom by Peter Huber Scientists can aid but if conclusions are based on conjecture, speculation and poor methodology then the opposite is true Lawyers use 'junk science' in the court Argues for the better control in relation to admissibility and for more responsible use of science in court Overstating and not based on scientific research - fingerprint enquiry in scotland shirley mcqueen [Kenneth Melson-President AAFS 2003] Science does not always equal truth [Strengthening Forensic Science in the United States 2009] National Academy of Science ('NAS') Report ([[https://www.ojp.gov/pdffiles1/nij/grants/228091.pdf]](https://www.ojp.gov/pdffiles1/nij/grants/228091.pdf)) End product of 3 years of research and testimony Committee on Identifying the Needs of the Forensic Sciences Community. National Research Council Alarming as it exposed many of the issues which existed in relation to forensic science Applicable in other countries NOT just the US - internationally relevant ['NAS' Report] NAS looked at the validity and signif underpinnings as shown below have a lack of scientific validation: Handwriting Firearms/bullets Tool Marks Footwear Impressions Tire Impressions Bitemarks Fingerprints Many of these longstanding evidence types Subjective analysis Lack of science Different results despite same techniques if applied by different people Anecdotal evidence in the courtroom-'I have seen this lots of times before'-so lack of proper research base Methods are a 'secret' Lack of admitted error due to lack of research Lack of research as a basis of these 'sciences' Subjective methods - relied on the person undertaking the method [Recommendations - read report pick one type ] Create a National Institute of Forensic Sciences (NIFS) Standardize terminology and reporting practices Expand research on the accuracy, reliability, and validity of the forensic sciences Remove forensic science services from the administrative control of law enforcement agencies and prosecutors' offices Support forensic science research on human observer bias and sources of error Develop tools for advancing measurement, validation, reliability, information sharing, and proficiency testing and to establish protocols for examinations, methods, and practices Require the mandatory accreditation of all forensic laboratories and certification for all forensic science practitioners Laboratories should establish routine quality assurance procedures Establish a national code of ethics with a mechanism for enforcement Support higher education in the form of forensic science graduate programs, to include scholarships and Fellowships Improve the medico-legal death investigation system Support AFIS interoperability through the development of standards Support the use of forensic science in homeland security - [PCAST Report 2016] - Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature Comparison Methods Written in response to the president asking if there were any further steps to address other than those that had already been taken by the Administration in response to the NAS report. PCAST report concentrated on feature comparison methods and identified 2 gaps: 1\. The need for clarity about the scientific standards for the validity and reliability of forensic methods and 2\. The need to evaluate specific forensic methods to determine whether they have been scientifically established to be valid and reliable Came up with a number of recommendations to try to address these including the introduction of evaluations of the scientific methodology of current and future technologies as well as directing legal professionals to ensure that expert testimony used was based on valid methods ([[https://obamawhitehouse.archives.gov/sites/default/files/microsites/ostp/PCAST/pcast\_forensic\_science\_report\_final.pdf]](https://obamawhitehouse.archives.gov/sites/default/files/microsites/ostp/PCAST/pcast_forensic_science_report_final.pdf)) [Issues] Forensic science is about the application of scientific methods to legal questions **It can** answer the Who, what, where, when, how and why? **BUT** Validity -- of methods and of practitioners Admissibility Bias Scientific Background-methodology, databases, research Interpretation Presentation of results