Quality Management in Forensic Science

Sean Doyle

• Publisher: Academic Press
• Year: 2018
• ISBN:
  9780128094242
• Topic: Droit
• Subtopic: Science médico-légale

Forensic science has been under scrutiny for some time, since the release of the NAS report in 2009. The report cited the need for standardized practices and the accreditation of crime labs. No longer can the forensic community take the position that cross-examination in a courtroom will expose weaknesses in methodology and execution.

Quality Management in Forensic Science covers a wide spectrum of forensic disciplines, relevant ISO and non-ISO standards, accreditation and quality management systems necessary in any forensic science laboratory. Written by a globally well-respected forensic scientist with decades of experience in the forensic science laboratory and on the stand, as an expert witness who is also a Fellow of both the Royal Society of Chemistry and the Chartered Society of Forensic Sciences. This book will be a must-have resource for all forensic science stakeholders, particularly law enforcement agents and lawyers less familiar with the impact of quality management on the reliability of scientific evidence.

• A comprehensive, multidisciplinary reference of scientific practices for use in the forensic laboratory
• Coverage from DNA to toxicology, from trace evidence to crime scene and beyond
• Extensive review of ISO and non-ISO standards, accreditation, QMS and much more
• Written by a foremost forensic scientist with decades of experience in the laboratory and as an expert witness

Section 1

Brief Introduction to Some Important Concepts and Key Terms

Abstract

This section introduces quality management as it applies to the management, practice, and delivery of forensic science. Its purpose is to ensure that all readers have a common understanding of the following: what forensic science is; what a forensic scientist does; the fundamental concepts and terms of quality management and metrology; and, in addition, to recognize the existence and potential effects of cognitive bias. Key terms such as “quality,” “standard,” and “science” are defined and explained, and the requirement for competence and validity are discussed.

Keywords

Cognitive bias; Competence; Expert witness; Forensic science; Forensic scientist; Metrology; Quality assurance; Quality control; Quality management; Quality standards; Science; Scientific method; Validation

1.1. Introduction

Quality management, to varying degrees, affects all aspects of forensic science. Thus, the readership for this work is expected to be broadly based, ranging, for example, from lawyers requiring an understanding of quality management to quality managers needing to know something of the law as it relates to the practice and delivery of forensic science. The aim of this book is to be of practical benefit to that wide readership.

To fully benefit from this work, a practical understanding of some of the concepts underlying forensic science and quality management is required. The purpose of this section is to introduce those concepts and ensure all readers, irrespective of background, have a sufficient knowledge and understanding to gain benefit.

Some of the more fundamental concepts, such as “science,” will be introduced and discussed briefly with sufficient detail to afford an understanding that is of practical use but not further developed. Other concepts, particularly those related to quality, will be introduced here and developed in some detail prior to a comprehensive treatment later in the work. Key terms will be defined and explained. In addition, some important issues will be mentioned in passing and returned to later in the work.

In describing and discussing the concepts, the aim has been to be as precise as possible without clouding the meaning for the nonspecialist reader. Readers specializing in a particular field may well have issues with the precision of some of the explanations offered and definitions given. However, a degree of leeway must be permitted to ensure that the nonspecialist gains an understanding. In later sections the terminology will be more precise.

This section covers the following four areas:

1. • Science,
2. • Quality,
3. • Metrology, and
4. • Cognitive bias.

However, before proceeding, the concept of a “standard” needs to be introduced. Dictionary definitions include an accepted or approved example of something against which others are judged or measured or an authorized model of a unit of measure or weight. Simple examples are the standard kilogram or meter in metrology. In science the standard would be the scientific method and in quality the quality management standard, ISO 9001:2015. The quality management definition of a standard is given later in Section 1.3.2.

1.2. Science

1.2.1. Science

What science is and is not has been and remains the subject of debate among philosophers (Rosenberg, 2000). However, the philosophy of science is of little relevance in a work intended to be of practical assistance. Nevertheless, a practical and precise understanding of the concept is required so that the subject of quality management in forensic science might be better set out and understood.

The word “science” has two basic meanings:

• 1. a body of knowledge; e.g., the science of chemistry, and
• 2. a method of enquiry; to find out about the universe.

Science, as a method of enquiry, relies on observation, theory, and experiment (in no particular order), the so-called observational and experimental procedures of science. Theories, or hypotheses, usually arise from observations made, experiments conducted, or, more generally, data gathered. The resulting theory (an explanation for the observations made or results obtained) is tested by further observations, experiments, or the gathering of more data and, if necessary, revised accordingly. This definition of science is useful as all forensic disciplines, including those based on comparison and largely relying on skill, such as marks and impressions, involve observation (i.e., making measurements and obtaining results or, more generally, gathering data) formulating hypotheses and often testing those hypotheses.

As scientific knowledge is often counterintuitive, scientific enquiry must be characterized by rationality, logic, and the avoidance of bias. The inferential methods of induction, deduction, and abduction all play a part. A detailed discussion of inference is beyond the scope of this work, but it does affect the interpretation of results obtained and this is discussed in Section 3.4.2.4. Jon Nordby (1999) in his book “Dead Reckoning: The art of Forensic Detection” gives a practical and easily understood description of each inferential method in a forensic science context.

To the above elements and characteristics of enquiry peer review should be added. There are different forms of peer review, but review by an expert of at least equal standing is a minimum requirement for the enquiry to qualify as scientific.

All these properties taken together constitute what is often termed the Scientific Method, the precise definition of which is also a matter of debate among philosophers, e.g., Karl Popper (1959) rejected the notion and Francis Bacon (1620) is credited with being its father.

For the purpose of this book, science is both a body of knowledge and a method of enquiry with the properties outlined above and as represented in Fig. 1.1.

It is worth noting in passing that the Law, particularly in judicial proceedings, is also a method of enquiry. However, where science admits no final conclusion the Law must. The “certainty” of the Law and the “uncertainty” of science are often at the root of issues in forensic science.

Figure 1.1 Scientific processes.

1.2.2. Forensic Science

Quite simply, forensic science is the use of science, or the scientific method, to help resolve disputes in civil or criminal law or, at a greater degree of abstraction, prove facts in issue. In comparison, law enforcement agencies tend to see the role of forensic science as aiding incident reconstruction, i.e., determining what happened at a crime scene and piecing together the story of events (UK Home Office, 2016). However, incident reconstruction is essentially another evidence type to be placed before a tribunal of fact. At the philosophical level, and to some extent at the practitioner level, there has been much debate regarding the processes by which the objective of forensic science might be achieved. Three of these processes are individualization, identification, and classification (Broeders, 2006).

Individualization is a type of classification and is the process of assigning an item of evidence to a class of one; examples might include DNA typing and fingerprint examination. In these disciplines, the aim is to identify an individual to the exclusion of all others.

DNA evidence is presented probabilistically and fingerprints, at the time of writing (2017), categorically¹, i.e., “match,” “no match,” or “inconclusive”. The difference in the way these evidence types are reported can be explained, in part, by the fact that fingerprints, and similar feature-comparison disciplines, are mainly the province of skilled examiners rather than scientists.

The concept of individualization has fueled much debate and scholarship with the consensus emerging that it may not be helpful (Saks and Koelhler, 2008; Cole, 2009; Kaye, 2010). Individualization is now considered an unachievable aim.

The quality issues raised by this debate will be explored more fully in Section 6.3. It is worth noting in passing that for decades many scholars considered forensic science to be the science of individualization (Kirk, 1963; Inman and Rud...