Risk Assessment in Forensic Practice

217 Pages·2022·4.517 MB·English

by  David Crighton

Risk Assessment in
Forensic Practice
Risk Assessment in Forensic Practice sets out a concise critical review of the way in
which risk is assessed in current forensic practice. Setting the area in its historical
context, this text outlines current practice in an accessible and clear format and
discusses major critiques as well as the ways in which current practice might be
developed to improve public protection.
Providing an account of the main issues involved in risk and probability and
the ways that these have been applied in practice, the book describes current
forensic practice in relation to the dominant algorithmic and checklist-based
methods. Critiques of these arising from social-legal, risk analysis and experi-
mental psychology perspectives are summarised, and questions of the accuracy,
fairness and lack of analysis are considered, along with the main challenges asso-
ciated with making group and individual predictions of events. The text rejects
the idea that clinical assessments of risk are generally ineffective and stresses
the role of environmental context, training and expertise in improving practice.
Through the author’s work in the field, this text also offers insight into the ways
in which current practice might be improved and calls for greater analysis and
methodological rigour.
Risk Assessment in Forensic Practice appeals to a wide range of forensic prac-
titioners including psychologists, psychiatrists, social workers, mental health
nurses and lawyers. The text is also relevant to those involved in management
and decision-making across forensic settings.
David Crighton is a Consultant Psychologist and Visiting Professor of Forensic
Psychology at Durham University, UK. He was previously Acting Chief/Deputy
Chief Psychologist at the Ministry of Justice, UK.
“Risk Assessment in Forensic Practice is an astonishing accomplishment. David
Crighton provides a trenchant and sweeping analysis of cutting-edge research
on the prediction and management of violent behavior. Historically grounded
and written in clear, jargon-free prose, this work is sure to have an immense and
long-lasting impact on the field.”
—John Monahan, PhD
John S. Shannon Distinguished Professor of Law,
Professor of Psychology, University of Virginia, USA
“David Crighton has done the field a great service in writing this book. He
provides an analysis of contemporary forensic practice that is both thoughtful
and balanced and which invites the reader to engage with foundational knowl-
edge about the history, meaning, and nature of risk. David then, rather gently it
should be said, draws our attention to the problems that will inevitably surface
if we continue to simply follow convention, before offering some concrete sug-
gestions for strengthening and advancing practice. Whilst this is both an easy
and engaging read, David challenges us all to do much better. Please take the
time to read this important contribution!”
—Professor Andrew Day
School of Social and Political Sciences, University of Melbourne, Australia
“This book is an articulate and authoritative examination of risk assessment in
forensic practice. An in-depth exploration of both current and historic issues
in theory and practice that will be a catalyst for much needed discussion and
reform. An invaluable and accessible resource for forensic psychologists and
other scholars, front-line practitioners and policy makers.”
—Dr Roxanne Khan
Director of Honour Abuse Research Matrix (HARM),
University of Central Lancashire, UK
“Based on the fundamental but often ignored distinction between risk and
uncertainty, this comprehensive and easy-to-read book provides an excellent
introduction to risk assessment, its tools, and its future. It is essential for forensic
practice, but also for a better understanding of human judgment, the nature of
probability, and the nature of rationality.”
—Gerd Gigerenzer
Max Planck Institute for Human Development, Berlin
New Frontiers in Forensic Psychology
Series Editors
Graham Towl is Professor of Forensic Psychology at Durham University and
was formerly Chief Psychologist at the Ministry of Justice, UK. He is the recipi-
ent of the British Psychological Society Award for Distinguished Contributions
to Professional Practice and forensic academic knowledge.
Tammi Walker is Professor of Forensic Psychology and Principal of St Cuth-
bert’s Society Durham University. She is a Chartered Psychologist and Fellow
of the British Psychological Society. Her research interests are gendered inter-
ventions for managing self-harm and suicide in prisons, mental health, physical
health and addressing sexual violence in universities.
New Frontiers in Forensic Psychology is a new series of forensic psychology books, which
brings together the most contemporary research in core and emerging topics in the field,
providing a comprehensive review of new areas of investigation in forensic psychology,
and new perspectives on existing topics of enquiry. The series includes original volumes
in which the authors are encouraged to explore unchartered territory, make cross-dis-
ciplinary evaluations, and where possible break new ground. The series is an essential
resource for senior undergraduates, postgraduates, researchers and practitioners across
forensic psychology, criminology and social policy.
Child to Parent Aggression and Violence
A Guidebook for Parents and Practitioners
Hue San Kuay and Graham Towl
New Perspectives on Arson and Firesetting
The Human-Fire Use Relationship
Faye K. Horsley
Risk Assessment in Forensic Practice
David Crighton
For a complete list of all books in this series, please visit the series page at: https://
www.routledge.com/New-Frontiers-in-Forensic-Psychology/book-series/NFFP

Risk Assessment in
Forensic Practice
DAVID CRIGHTON
Cover image: Getty Images
First published 2023
by Routledge
4 Park Square, Milton Park, Abingdon, Oxon OX14 4RN
and by Routledge
605 Third Avenue, New York, NY 10158
Routledge is an imprint of the Taylor & Francis Group, an informa business
© 2023 David Crighton
The right of David Crighton to be identified as author of this work has been
asserted in accordance with sections 77 and 78 of the Copyright, Designs and
Patents Act 1988.
All rights reserved. No part of this book may be reprinted or reproduced or
utilised in any form or by any electronic, mechanical, or other means, now
known or hereafter invented, including photocopying and recording, or in any
information storage or retrieval system, without permission in writing from the
publishers.
Trademark notice: Product or corporate names may be trademarks or registered
trademarks, and are used only for identification and explanation without intent
to infringe.
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library
Library of Congress Cataloging-in-Publication Data
Names: Crighton, David A., 1964- author.
Title: Risk assessment in forensic practice / by David Crighton.
Description: Abingdon, Oxon; New York, NY: Routledge, 2022. |
Series: New frontiers in forensic psychology | Includes bibliographical references and index. |
Identifiers: LCCN 2021060885 (print) | LCCN 2021060886 (ebook) |
ISBN 9780367622671 (hardback) | ISBN 9780367622534 (paperback) |
ISBN 9781003108665 (ebook)
Subjects: LCSH: Forensic psychology. | Forensic sociology. | Risk assessment.
Classification: LCC RA1148 .C737 2022 (print) | LCC RA1148 (ebook) |
DDC 614/.15—dc23/eng/20220121
LC record available at https://lccn.loc.gov/2021060885
LC ebook record available at https://lccn.loc.gov/2021060886
ISBN: 978-0-367-62267-1 (hbk)
ISBN: 978-0-367-62253-4 (pbk)
ISBN: 978-1-003-10866-5 (ebk)
DOI: 10.4324/9781003108665
Typeset in Avenir and Dante
by codeMantra
Contents
Series Foreword xi
Acknowledgements xiii
Disclosure xiii
Introduction 1
1 Key Issues in Risk 4
Risk and Uncertainty 4
Probability 8
Measuring Probability 9
The Principle of Indifference 11
Types of Probability 12
Relative Frequency Probability 12
Knowledge- Based Probability 13
Problems with Knowledge- Based Probability 16
Applying Probability 16
Descriptive and Inferential Statistics 16
Conclusion 17
2 The Language of Risk 19
Risk Assessment 22
Risk Treatment 23
Dose Response 24
Risk Management 25
viii Contents
Cautionary and Precautionary Principles 26
Robustness and Resilience 27
Risk and Protective Factors 27
Conclusion 30
3 Current Practice in Risk: Actuarial and Algorithmic Approaches 31
Use of Actuarial and Algorithmic Approaches in Practice 34
Policing 34
Sentencing and Conditional Release 35
Risk Treatment 37
The Case for Using Actuarial and Algorithmic RAIs 40
Conclusion 42
4 Current Practice in Risk: Structured Clinical Judgement Approaches 43
Use in Practice 47
Policing 47
Sentencing and Conditional Release 51
Risk Treatment 52
The Case for Using Checklist RAIs 54
Conclusion 55
5 Critiques of Current Practice: Socio-L egal Perspectives 56
Fairness 58
Accuracy 67
Individual and G roup- Based Predictions 70
Impact 77
Conclusion 78
6 Critiques of Current Practice: Risk Analysis Perspectives 80
Risk Management 85
Risk Analysis 87
Measuring Risk 88
Simplified Qualitative Analysis 90
Standard Qualitative and/o r Quantitative Analysis 90
M odel-B ased and Primarily Quantitative Methods 92
Treating Risk as an Expected Value 93
Criticisms of Using Relative Frequency Probability 95
Criticisms of Using K nowledge-B ased Probability 97
Contents ix
Syntactic Criterion 99
Pragmatic Criteria 99
Calibration 99
Treating Risk as a Product of History 100
Standardisation and Consensus 103
Using Models 104
Conclusion 104
7 Critiques of Current Practice: Psychological Perspectives 106
Unbounded Rationality 108
Optimisation Under Constraints 108
Cognitive Illusions 109
Ecological Rationality 110
Biases Associated with Cognitive Illusions 110
Representativeness 110
Availability 111
Anchoring and Adjustment 111
Affect 112
Heuristics and Judgement 112
Critiques of Cognitive Illusions Research 115
Some Problems while Using Content- Blind Norms 118
Studies of Heuristics 123
Are Cognitive Illusions and Ecological Rationality
Essentially Similar? 124
The Adaptive Toolbox 125
Conclusion 128
8 Dealing with Risk Better: Analysis and Treatment of Risks 129
The Scale of the Problem 130
Analysing Risks 132
Barriers to Change 134
Doing Better 138
Risk Analysis: Planning 139
Risk Analysis: Methods 140
Cause and Effect Analysis ( CEA) or Ishikawa
Diagrams 143
Structured What If Technique (S WIFT) 143
Fault Tree Analysis ( FTA) 144
Event Tree Analyses (E TA) 144