1st Edition
Introduction to Forensic DNA Evidence for Criminal Justice Professionals
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.
History of forensic DNA profiling in criminal investigations
Discovery of structure and importance of DNA molecule: A Nobel prize
DNA and concept of individuality
Alec Jeffreys and the world’s first murder case solved by DNA
Early criminal court challenges to DNA technology
Changing the face of forensic science: The value of biological evidence
Strengths and limitations of DNA profiling evidence
Introduction: Power and caution
Discrimination power of DNA profiling
Genetic basis for DNA profiling
Stability of DNA profiling
Persuasive statistics
Relatives
DNA databases
DNA intelligence-led policing
Mass disasters
DNA evidence in context
Time of deposition: Transfer and persistence of DNA
Relevant evidence?
Relevant exhibits?
"CSI effect" and the notion of infallible forensic evidence
Relationships of lawyers and scientists
DNA profiling basics
What is DNA?
Biological materials allowing DNA profiling
Reference samples
Current profiling technique: Short tandem repeats (STRs)
Reading tables of alleles
Obtaining DNA profiles
Time required to obtain DNA profiles
Designating peaks
Case documentation and review
Evidential value and statistics
Interpreting DNA profiles
Statistical approaches and obtaining final statistics
Legal fallacies
Understanding reports: Common phrases and their meanings
Sampling correction and uncertainty
Relevant population and impact on statistical value
Relatives
Partial profiles, low levels, and mixtures
Partial profiles
Low level and suboptimal profiles
DNA mixtures from two or more people
Mixture interpretation steps
Low template mixtures
Complex mixtures
Y-STR profiling
Benefits
Theory
Statistics
Number of male contributors to Y-
STR profile
Determining mixture ratios
Combining statistics from autosomal and Y-STR profiling
Other DNA techniques including mitochondrial DNA
DNA analysis of bone
Mitochondrial DNA basics
Statistics in mitochondrial DNA analysis
Contamination
Mixture mitochondrial DNA profiles
Familial DNA searching
Domestic animal hair
Other techniques
Concerns and controversies
Quality issues
Relevant sample testing
Contamination
Interpretation issues
Error rates
Overreliance on DNA technology
Interpretation of DNA profiles: Objectivity and subjectivity
Retesting of samples
Adversarial system
Misconception about exact science
Obligations
DNA pointers for criminal justice professionals
Advantages of DNA profiling
Querying DNA evidence: Advice for the prosecution and the defense
Warning signs
Was all evidence tested?
Pretrial review
Suggested cross-examination questions
Discovery requests
Appendix A: Glossary of terms used in reports and testimony
Appendix B: Selected DNA issues and case examples
Appendix C: Steps in review of evidence
Index
Biography
Jane Moira Taupin
. . . a valuable introduction, with many useful examples. The limitations of the subject, the need for caution in interpretation and problems such as contamination and degradation are expertly handled.
—Graham Fricke, QC, retired County Court Judge
Overall this book is very clearly written. The author is able to simplify complex scientific terms and concepts into information understandable by a wide audience with divers experiences and backgrounds … This book will serve as a great reference for nonscientists who routinely encounter DNA evidence within the criminal justice system and for students interested in an introduction to forensic DNA evidence.
—Book review by Krista E. Latham, PhD, appearing in the Journal of Forensic Sciences, July 2014, Vol. 59, No. 4