Interpretation of DNA profile matches depends on the use of statistical weights. This text provides the background information in statistics and genetics for the reader to arrive at these weights.

Now in its second edition, Forensic DNA Evidence Interpretation is the most comprehensive resource for DNA casework available today. Written by leaders in the fields of biology and statistics, including a contribution from Peter Gill, the father of DNA analysis, the book emphasizes the interpretation of test results and provides the necessary formulae in an easily accessible manner. This latest edition is fully updated and includes current and emerging techniques in this fast-moving field. The book begins by reviewing all pertinent biology, and then provides information on every aspect of DNA analysis. This includes modern interpretation methods and contemporary population genetic models available for estimating DNA frequencies or likelihood ratios. Following a chapter on procedures for validating databases, the text presents overviews and performance assessments of both modern sampling uncertainty methods and current paternity testing techniques, including new guidelines on paternity testing in alignment with the International Society for Forensic Genetics. Later chapters discuss the latest methods for mixture analysis, LCN (ultra trace) analysis and non-autosomal (mito, X, and Y) DNA analysis. The text concludes with an overview of procedures for disaster victim identification and information on DNA intelligence databases. Highlights of the second edition include: New information about PCR processes, heterozygote balance and back and forward stuttering New information on the interpretation of low template DNA, drop models and continuous models Additional coverage of lineage marker subpopulation effects, mixtures and combinations with autosomal markers This authoritative book provides a link among the biological, forensic, and interpretative domains of the DNA profiling field. It continues to serve as an invaluable resource that allows forensic scientists, technicians, molecular biologists and attorneys to use forensic DNA evidence to its greatest potential.

In 1992 the National Research Council issued DNA Technology in Forensic Science, a book that documented the state of the art in this emerging field. Recently, this volume was brought to worldwide attention in the murder trial of celebrity O. J. Simpson. The Evaluation of Forensic DNA Evidence reports on developments in population genetics and statistics since the original volume was published. The committee comments on statements in the original book that proved controversial or that have been misapplied in the courts. This volume offers recommendations for handling DNA samples, performing calculations, and other aspects of using DNA as a forensic toolâ€"modifying some recommendations presented in the 1992 volume. The update addresses two major areas: Determination of DNA profiles. The committee considers how laboratory errors (particularly false matches) can arise, how errors might be reduced, and how to take into account the fact that the error rate can never be reduced to zero. Interpretation of a finding that the DNA profile of a suspect or victim matches the evidence DNA. The committee addresses controversies in population genetics, exploring the problems that arise from the mixture of groups and subgroups in the American population and how this substructure can be accounted for in calculating frequencies. This volume examines statistical issues in interpreting frequencies as probabilities, including adjustments when a suspect is found through a database search. The committee includes a detailed discussion of what its recommendations would mean in the courtroom, with numerous case citations. By resolving several remaining issues in the evaluation of this increasingly important area of forensic evidence, this technical update will be important to forensic scientists and population geneticistsâ€"and helpful to attorneys, judges, and others who need to understand DNA and the law. Anyone working in laboratories and in the courts or anyone studying this issue should own this book.

Matching DNA samples from crime scenes and suspects is rapidly becoming a key source of evidence for use in our justice system. DNA Technology in Forensic Science offers recommendations for resolving crucial questions that are emerging as DNA typing becomes more widespread. The volume addresses key issues: Quality and reliability in DNA typing, including the introduction of new technologies, problems of standardization, and approaches to certification. DNA typing in the courtroom, including issues of population genetics, levels of understanding among judges and juries, and admissibility. Societal issues, such as privacy of DNA data, storage of samples and data, and the rights of defendants to quality testing technology. Combining this original volume with the new update-The Evaluation of Forensic DNA Evidence-provides the complete, up-to-date picture of this highly important and visible topic. This volume offers important guidance to anyone working with this emerging law enforcement tool: policymakers, specialists in criminal law, forensic scientists, geneticists, researchers, faculty, and students.

Misleading DNA Evidence: A Guide for Scientists, Judges, and Lawyers presents the reasons miscarriages of justice can occur when dealing with DNA, what the role of the forensic scientist is throughout the process, and how judges and lawyers can educate themselves about all of the possibilities to consider when dealing with cases that involve DNA evidence. DNA has become the gold standard by which a person can be placed at the scene of a crime, and the past decade has seen great advances in this powerful crime solving tool. But the statistics that analysts can attach to DNA evidence often vary, and in some cases the statistical weight assigned to that match, can vary enormously. The numbers provided to juries often overstate the evidence, and can result in a wrongful conviction. In addition to statistics, the way the evidence is collected, stored and analyzed can also result in a wrongful conviction due to contamination. This book reviews high-profile and somewhat contentious cases to illustrate these points, including the death of Meredith Kercher. It examines crucial topics such as characterization of errors and determination of error rates, reporting DNA profiles and the source and sub-source levels, and the essentials of statement writing. It is a concise, readable resource that will help not only scientists, but legal professionals with limited scientific backgrounds, to understand the intricacies of DNA use in the justice system. - Ideal reference for scientists and for those without extensive scientific backgrounds - Written by one of the pioneers in forensic DNA typing and interpretation of DNA profiling results - Ideal format for travel, court environments, or wherever easy access to reference material is vital

This book explains the correct logical approach to analysis of forensic scientific evidence. The focus is on general methods of analysis applicable to all forms of evidence. It starts by explaining the general principles and then applies them to issues in DNA and other important forms of scientific evidence as examples. Like the first edition, the book analyses real legal cases and judgments rather than hypothetical examples and shows how the problems perceived in those cases would have been solved by a correct logical approach. The book is written to be understood both by forensic scientists preparing their evidence and by lawyers and judges who have to deal with it. The analysis is tied back both to basic scientific principles and to the principles of the law of evidence. This book will also be essential reading for law students taking evidence or forensic science papers and science students studying the application of their scientific specialisation to forensic questions.

Giving the reader an in-depth understanding of DNA evidence in criminal practice, this text explains in clear language how DNA evidence is obtained and how it can be successfully challenged in court to minimize its impact or even dismiss it completely. Since it first entered the criminal legal practice DNA has become an indispensable tool in fighting crime, as it allows both unambiguous identification of the criminal by traces of biological material left at the crime scene as well as acquitting innocent suspects. This book: outlines the various types of testing used to obtain DNA evidence highlights the weaknesses of DNA testing, presenting and discussing defence strategies for refuting DNA evidence shows how DNA should be treated as just another piece of evidence and how on its own it is often not enough to convict someone of a particular crime. This book is essential reading for students and practitioners of criminal law and practice and forensic science and law.

The use of DNA profiling in forensic cases has been considered the most innovative technique in forensic science since fingerprinting, yet for those with limited scientific knowledge, understanding DNA enough to utilize it properly can be a daunting task. Introduction to Forensic DNA Evidence for Criminal Justice Professionals is designed for nonscientific readers who need to learn how to effectively use forensic DNA in criminal cases.Written by a forensic scientist world renowned for her expertise in clothing examination, the book provides a balanced perspective on the weight of DNA evidence. Going beyond a simple explanation of the methodology, it arms attorneys and other criminal justice professionals with knowledge of the strengths and limitations of the evidence, including the danger in relying on DNA statistical probabilities in the determination of guilt. The book covers the most common DNA methods used in criminal trials today nuclear DNA short tandem repeat (STR) techniques, mitochondrial DNA, and Y-STR profiling. It helps prosecutors know when to emphasize DNA evidence or proceed with trial in the absence of such evidence. It assists defense lawyers in knowing when to challenge DNA evidence and perhaps employ an independent expert, when to focus elsewhere, or when to secure the advantage of an early guilty plea.By imparting practical and theoretical knowledge in an accessible manner, the book demystifies the topic to help both sides of the adversarial system understand where DNA evidence fits within the context of the case.

DNA testing and its forensic analysis are recognized as the “gold standard” in forensic identification science methods. However, there is a great need for a hands-on step-by-step guide to teach the forensic DNA community how to interpret DNA mixtures, how to assign a likelihood ratio, and how to use the subsequent likelihood ratio when reporting interpretation conclusions. Forensic DNA Profiling: A Practical Guide to Assigning Likelihood Ratios will provide a roadmap for labs all over the world and the next generation of analysts who need this foundational understanding. The techniques used in forensic DNA analysis are based upon the accepted principles of molecular biology. The interpretation of a good-quality DNA profile generated from a crime scene stain from a single-source donor provides an unambiguous result when using the most modern forensic DNA methods. Unfortunately, many crime scene profiles are not single source. They are described as mixed since they contain DNA from two or more individuals. Interpretation of DNA mixtures represents one of the greatest challenges to the forensic DNA analyst. As such, the book introduces terms used to describe DNA profiles and profile interpretation. Chapters explain DNA extraction methods, the polymerase chain reaction (PCR), capillary electrophoresis (CE), likelihood ratios (LRs) and their interpretation, and population genetic models—including Mendelian inheritance and Hardy-Weinberg equilibrium. It is important that analysts understand how LRs are generated in a probabilistic framework, ideally with an appreciation of both semicontinuous and fully continuous probabilistic approaches. KEY FEATURES: • The first book to focus entirely on DNA mixtures and the complexities involved with interpreting the results • Takes a hands-on approach offering theory with worked examples and exercises to be easily understood and implementable by laboratory personnel • New methods, heretofore unpublished previously, provide a means to innovate deconvoluting a mixed DNA profile, assign an LR, and appropriately report the weight of evidence • Includes a chapter on assigning LRs for close relatives (i.e., “It’s not me, it was my brother”), and discusses strategies for the validation of probabilistic genotyping software Forensic DNA Profiling fills the void for labs unfamiliar with LRs, and moving to probabilistic solutions, and for labs already familiar with LRs, but wishing to understand how they are calculated in more detail. The book will be a welcome read for lab professionals and technicians, students, and legal professionals seeking to understand and apply the techniques covered.