Statistical Analysis in Forensic Science (original) (raw)

The interpretation of elemental composition measurements from forensic glass evidence: I

Science & Justice, 1997

Previously the authors suggested the use of Hotelling's T 2 statistic, a multivariate equivalent of Student's t-test, for determining a 'match' between glass fragments recovered from a suspect and a 'control' sample of glass fragments from the crime scene [I]. The use of Hotelling's T2 test was suggested as a replacement to either range overlap methods or '3 sigma' methods. While Hotelling's T2 test is certainly a better approach than any '3 sigma' or range overlap method, it is still subject to the weaknesses inherent in any hypothesis testing approach. This paper will introduce a continuous Bayesian method based on Hotelling's T2 test that overcomes these weaknesses.

Statistics in Forensic Research

Statistics has an immensely important role in the forensic science as well as all of the scientific disciplines. Quantitative tools, based on statistical methods are used to compare the samples from a crime scene (i.e. fibers, DNA profiles, drug seizures or glass fragments) with reference materials, often from suspects or other crime scenes. Basic statistics, statistical distributions and the probability theory allow us to decide whether these samples are similar or distinguishable. Also, tables (i.e. frequency and cross tables) and graphs (i.e. bar, error graphs and scatter plots) are the most useful tools in the analysis and interpretation of experimental data within the forensic discipline. More sophisticated methods of data analysis are needed for the interpretation of toxicological measurements on drug metabolites in the body, determining time since death, reconstructing bullet trajectories or blood-spatter patterns. All of these are based on an understanding of mathematical functions, non-linear and linear regression, and even trigonometry. Also, both univariate and multivariate hypothesis testing methods such as correlation analysis, t-test, analysis of variance, chi-square test, cluster analysis, discriminant analysis and logistic regression analysis are frequently used to analyze the data in forensic research.

FORENSIC SCIENCE IN CRIMINAL PROCEDURE

FORENSIC SCIENCE IN CRIMINAL PROCEDURE, 2021

Forensic science in criminal procedure is a textbook that stemmed from the need to compile scientific knowledge of various scientific disciplinesforensic medicine, criminology, and medical criminology. The multidisciplinary nature of this scientific discipline has often been an obstacle for the publication of scientific works in this field in the past. In fact, legal experts hesitate to enter the domain of medical science due to the lack of expertise, while on the other side medical experts exclusively concentrate on the achievements of medical sciences. However, there is a practical need for the unification of scientific developments in such divergent scientific disciplines. For all those reasons, written sources in this area are commonly outdated, obsolete, and sporadic. The author's purpose was to expand the level of works in the field and introduce new scientific knowledge and technological developments achieved so far. The textbook would be useful for law school, forensic science, and medical students on one side and could also be used by persons conducting activities related to crime detection, crime scene investigation, expert evaluations, autopsies, etc. Author Academic prof. dr. Nedeljko Stanković K CHAPTER I THEORETICAL-METHODOLOGICAL APPROACH 1. THE NOTION OF FORENSIC SCIENCE…………………………………25

Forensic Science Evidence in Question

Expert Evidence and Scientific Proof in Criminal Trials, 2017

How should forensic scientists and other expert witnesses present their evidence in court? What kinds and quality of data can experts properly draw on in formulating their conclusions? In an important recent decision in R. v T 1 the Court of Appeal revisited these perennial questions, with the complicating twist that the evidence in question incorporated quantified probabilities, not all of which were based on statistical data. Recalling the sceptical tenor of previous judgments addressing the role of probability in the evaluation of scientific evidence, 2 the Court of Appeal in R. v T condemned the expert's methodology and served notice that it should not be repeated in future, a ruling which rapidly reverberated around the forensic science community causing consternation, and even dismay, amongst many seasoned practitioners. 3 At such moments of perceived crisis it is essential to retain a sense of perspective. There is, in fact, much to welcome in the Court of Appeal's judgment in R. v T, starting with the court's commendable determination to subject the quality of expert evidence adduced in criminal litigation to searching scrutiny. English courts have not consistently risen to this challenge, sometimes accepting rather too easily the validity of questionable scientific techniques. 4 However, the Court of Appeal's reasoning in R. v T is not always easy to follow, and there are certain passages in the judgment which, taken out of context, might even appear to confirm forensic scientists' worst fears. This article offers a constructive reading of R. v T,

ISSUES OF FORENSIC SCIENCE 309(3) 2020 45 FORENSIC PRACTICE

Identification of the side of window glass destruction as a type of diagnostic tasts of the forensic examination, 2020

The peculiarities of the diagnostic tasks of the forensic traces examination in determining the distraction side of the window, depending on the location of the relief drawing on the edges of the cracks and the end surfaces of the fragments are considered in this article. The effects of force on glass have been have been studied in this article. The changes in the lateral force and bending moment affecting the glass plate, which is loaded with force in the middle of the section and at the free end, are analyzed. The sections in which internal force factors have maximum values are established. The order of formation of radial and concentric cracks on the window glass is justified. The relief pattern on the edges of the cracks and the end surfaces of the glass fragments was examined. The mechanism for forming radial and concentric cracks of arcuate-shaped lines and serrations on the sides and ribs is justified. The process of formation of the intended radial cracks has been investigated and justified. Recommendations for removing and directing objects from glass for study are made.

Forensic Chemistry is an Important Part of any Forensic Investigation

Forensic chemistry is applied chemistry in a legal environment. Experts in this field have a wide range of methods and instruments to help identify unknown substances. The range of different methods is important because of the destructive nature of some instruments and the number of possible unknown substances that can be found at the scene. Chemicalphysical expertise has a continuous tradition that stretches back several decades. Whether they are an integral part of a department, division or service as an organizational unit, from its beginnings until today, chemical and physical expertise covers the widest area of work, which includes expertise of traces left after explosion, arson, traffic accidents, burglary, pollution environment, etc. In order to be as objective as possible, they apply a number of instrumental methods of analysis in their work. Which method will be applied depends primarily on the type and amount of trace, and it is always necessary to choose the method that will reduce the possibility of sample contamination. Since it is necessary to ensure the preservation of material evidence during the expertise, whenever possible, non-destructive methods certainly have an advantage. Developed methods can analyze a variety of materials including: pigments, glass, building materials, soils, minerals, metals, metal alloys and their corrosion products, organic and bioinorganic materials such as wood, textile, paper, oil-based binders, sugars, adhesives, natural or synthetic coatings, then adhesive tapes, cosmetics, plastics, flammable liquids, post-explosion residues and a whole range of organic and inorganic chemicals.

Basic Principles of Forensic Chemistry

2012

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Fifty Years of Forensic Science

Fifty Years of Forensic Science, 2010

Forensic apartheid? 39 (2)-1999 Let me through, I'm a ummmm. .. 39 (3)-1999 Something nasty hiding. .. (4)-1999 From Bach to Schoenberg 42 (2)-2002 A professional body for forensic scientists 45 (1)-2005 Professionalism-duties and privileges 45 (3)-2005 Who guards the guards? 45 (4)-2005 Everything changes and nothing is constant 47 (2)-2007 Eight years on 47 (2)-2007 Regulation of Forensic Physicians and the CRFP 47 (3)-2007 CPD, an effective means of professional development.. .or is it? 48 (1)-2008 President of the Forensic Science Society 48 (3)-2008 The forensic science regulator 43 (1)-2003 Hunting truffles 44 (1)-2004 Reiterative justice? 45 (2)-2005 Science & Justice-DNA and the courts CONTENTS ix 47 (4)-2007 DNA-what's next? 48 (4)-2008 Do we value research? 49 (1)-Lessons from the past 49 (2)-2009 IRMS SECTION III: EVALUATION AND INTERPRETATION OF EVIDENCE (3)-1979 Away with the fuzz 23 (1)-1983 Patience 23 (1a)-1983 Statistics and forensic science-a fruitful partnership 23 (1b)-1983 The probability of exclusion or likelihood of guilt of an accused: Paternity 23 (1c)-1983 The probability of non-discrimination or likelihood of guilt of an accused: Criminal Identification 23 (1d)-1983 What is the probability that this blood came from that person? A meaningful question? 23 (1e)-1983 A frame of reference or Garbage in, Garbage out 23 (4)-1983 On circumstantial evidence 26 (3)-1986 Evaluation of associative physical evidence 23 (3a)-1987 The use of statistics in forensic science 23 (3b)-1987 The use of statistics in forensic science 28 (3)-1988 Heads we win 37 (2)-1997 Does justice require less precision than chemistry? 43 (2)-2003 Sally Clark-a lesson for us all 44 (2)-2004 Context-free forensic science 46 (1)-2006 Lies, damn lies and statistics SECTION IV: EDUCATION IN FORENSIC SCIENCES 2 (1)-1961 Research and teaching in forensic science 2 (1)-1961 A preliminary survey of education and research in the forensic sciences in the United Kingdom 9 (1&2)-1968 Education in the forensic sciences 11 (1)-1971 What is the future for the study and practice of the forensic sciences in Britain? 16 (2)-1976 The Greeks had a word for it 44 (4)-2004 Wither academic forensic science? 48 (2)-2008 Educating the next generation 48 (4)-2008 Letter to the Editor 48 (4)-2008 Letter to the Editor 49 (1)-2009 Letter to the Editor SECTION V: FORENSIC SCIENCE AND THE LAW 1 (2)-1960 An expert witness looks at the courts 3 (2)-1962 The design of law courts 6 (4)-1965 Bowlers, brollies and bifocals 8 (1)-1967 The expert witness 8 (2)-1967 Two encouraging cases x CONTENTS 10 (1)-1970 Law and order 12 (2)-1972 There is a time to speak 12 (3)-1972 Not Pygmalion likely 12 (4)-1972 Where have all the lawyers gone? 13 (2)-An honest opinion (3)-Modern times 16 (3a)-1976 A camel is a horse.. . 17 (2&3)-1977 The four letter swear word 18 (3&4)-1978 Not for the faint hearted 19 (2)-1979 Preliminary hearings-just or unjust-justified or unjustified (2)-1980 The canons of expertise 24 (2)-Have you heard the one about. .. 24 (5)-1984 Master or servant? 25 (4)-1985 Don't Panic 27 (4)-1987 Philosophy and obligations of a state-funded forensic science laboratory 27 (5)-1987 Answers are easy 29 (2)-1989 Science and law, a marriage of opposites 34 (3)-1994 The image of the scientist and the lawyer 38 (2)-1998 The role of the forensic scientist in an inquisitorial system of justice 40 (2)-2000 And what of the evidence! 41 (3)-2001 The boundaries of expert evidence 41 (4)-2001 Reform of the criminal justice system in England and Wales 42 (3)-2002 Justice in a goldfish bowl 42 (4)-2002 Gristle in the sausage.. . 43 (3)-2003 Coroners-what next for death investigation in England and Wales? 44 (3)-2004 The Human Tissue Bill-an opportunity about to be missed? 46 (2)-2006 All's fair in love and war