Gisli Hannes Gudjonsson is an Emeritus Professor of Forensic Psychology at the Institute of Psychiatry, Psychology & Neuroscience, King’s College London, and a Professor in the Psychology Department at Reykjavík University. Prior to his retirement from King’s College on 1 January 2012 he was the Head of Forensic Psychology Services for the Lambeth Forensic Services and Medium Secure Unit at the South London and Maudsley NHS Trust. Professor Gudjonsson is a Fellow of the British Psychological Society and a registered practitioner (clinical and forensic) with the Health Care Professions Council.

Professor Gudjonsson pioneered the empirical measurement of interrogative suggestibility and has published extensively in the areas of psychological vulnerabilities, false confessions, and police interviewing. He has provided expert evaluation in a number of high profile cases, including the Guildford Four, the Birmingham Six, Judith Ward, Engin Raghip, Stephen Miller, Donald Pendleton, Andrew Evans, Ian Lawless, and Raymond Gilmour. He has also testified in high profile cases in the USA, Canada, Norway, Iceland, and Israel.

Professor Gudjonsson was awarded an Honorary Doctorate in Medicine in 2001 by the University of Iceland for services to forensic psychiatry and psychology. In April 2009 the British Psychological Society presented him with a Lifetime Achievement Award. He was awarded The European Association of Psychology and Law Life Time Achievement Award for 2012, and received the 2017 Tom Williamson (iIIRG) Life Time Achievement Award ‘In recognition for his outstanding lifetime achievement to the area of investigative interviewing’ (iIIRG is the International Investigative Interviewing Research Group). He was appointed a Commander of the Order of the British Empire (CBE) in the Queen’s Birthday 2011 Honours List for services to clinical psychology.

Professor Gudjonsson is the author of The Psychology of Interrogations, Confessions and Testimony (John Wiley & Sons, 1992), The Psychology of Interrogations and Confessions, A Handbook (John Wiley & Sons, 2003), The Gudjonsson Suggestibility Scales Manual (Psychology Press, 1997), The Causes and Cures of Criminality (Plenum Press, 1989, jointly written with Hans Eysenck), and Forensic Psychology: A Guide to Practice (Routledge, 1998, jointly written with Lionel Haward).

The Wiley Series in the Psychology of Crime, Policing and Law publishes both single and multi‐authored monographs and edited reviews of important and emerging areas of contemporary research. The purpose of this series is not merely to present research findings in a clear and readable form, but also to bring out their implications for both practice and policy. Books in this series are useful not only to psychologists, but also to all those involved in crime detection and prevention, child protection, policing, and judicial processes.

The author of this new volume, Professor Gisli H. Gudjonsson, CBE, is pre‐eminent in the field of false confession, a subject of concern to all criminal justice systems. Professor Gudjonsson has devoted much of his professional career to studying this issue, both as a researcher and as an expert witness in cases where contentious confessions are an issue, not only in the United Kingdom but throughout the world. His first book The Psychology of Interrogations, Confessions and Testimony launched this book series in 1992. It described how psychological pressures induced by then accepted interrogation techniques could lead to false and sometimes self‐incriminating testimony, which in turn could result in miscarriages of justice. He illustrated this thesis with reference to a number of the high‐profile cases in which he had given evidence, notably those of the ‘Birmingham Six’ and the ‘Guildford Four’, where coercive interview tactics had resulted in innocent suspects confessing while in police custody to involvement in these shocking crimes. Despite their subsequent retractions of involvement, all defendants were found guilty at trial and sentenced to lengthy prison terms. Their eventual release by the Court of Appeal owed in part to Professor Gudjonsson’s expert testimony. He demonstrated through systematic analyses of the personal vulnerabilities of some of the defendants high levels of ‘interrogative suggestibility’, which in turn made their confessions an unsafe basis for conviction.

His second book The Psychology of Interrogations and Confessions: A Handbook appeared in the series in 2003 and summarized developments in the concept of interrogative suggestibility, again illustrated by many new cases in which he had given expert evidence. Much of that evidence was derived from administration of the Gudjonsson Suggestibility Scales, a psychometric tool he developed to tease out the potential effects of suggestibility and compliance in cases of contested confession evidence. The handbook also summarized the growing research literature on false confessions, much of which had been sparked by his pioneering work. His demonstration of the impact on evidence of coercive interview procedures led in turn to major changes being introduced to police interviewing procedures in England and Wales, although sadly, not in the United States, where disputed confessions remain a major concern for justice (Kassin, 1997).

Professor Gudjonsson’s new book describes two murder cases in his native Iceland following the disappearance of two young men, Gudmundur Einarsson and Geirfinnur Einarsson, in 1974. No trace of the men was ever found, but police investigations led eventually to the arrest and subsequent trials for murder of six young persons. The evidence against them rested almost entirely on their confessions and no forensic evidence was offered at trial. The confessions themselves, secured in many instances after long periods of solitary confinement and intensive interrogation, were contradictory. In an effort to iron out such contradictions, the authorities involved a former senior investigator with the German police who conducted a further round of interrogations, which in turn led to further unreliable admissions. In the subsequent trial, the investigator’s findings were used by the prosecution, while the defendants, now freed from oppressive detention, retracted their earlier confessions. All were found guilty and sentenced to lengthy prison terms.

As Professor Gudjonsson explains, when he examined the evidence in these cases, they showed the same pattern of coerced confession followed by subsequent retraction, reminiscent of many other proven cases of false confessions that he had investigated. His careful and detailed examination of the evidence and the experiences and personality of the accused led him to conclude that all six were innocent and that a serious miscarriage of justice had taken place. By a curious quirk of fate, he had met five of the six accused as a young police officer conducting research for a psychology dissertation. In 2012, he returned to Iceland as an internationally renowned expert, to assist with an official enquiry into the disputed convictions. Sadly, for two of the six, this development came too late, but the remaining four and the families of the two deceased men now await the decision of the Iceland Supreme Court to see whether their names will finally be cleared.

The Psychology of False Confessions: Forty Years of Science and Practice is a fascinating and personal account of the mysterious disappearances, and their subsequent investigation and the fight of the accused and their supporters for justice. In addition, Gudjonsson uses the opportunity to look back over his own career and to review the latest research on false confessions, with particular relevance to the travails of the Icelandic six. It is a story that can be read with profit by psychologists, criminologists, and lawyers and indeed, all those concerned with the prosecution of crime and the importance of justice.

This book would not have been written had it not been for my becoming involved as a ‘confession expert’ in two Icelandic cases in 2011. The cases involved the disappearances of two unrelated men, Gudmundur Einarsson and Geirfinnur Einarsson, in January and November 1974, respectively. At the end of December 1975 and beginning of January 1976, the Reykjavík Criminal Investigation Police commenced murder investigations without the victims’ bodies, a known crime scene, or credible leads. Despite the investigations floundering on numerous occasions, after eliciting confessions that were massively contradictory and could not be independently corroborated, six young people were convicted and imprisoned on the basis of their confessions. The convicted persons Saevar Ciesielski, Kristján Vidarsson, Tryggvi Leifsson, Gudjón Skarphédinsson, Erla Bolladóttir, and Albert Skaftason all claimed to be innocent and alleged that their confessions were coerced by the police. Saevar and Tryggvi are now dead, but the other four convicted persons and the families of the two dead men are currently fighting to have their convictions overturned.

In the summer of 1976 while working as a detective in Reykjavík, I met four of the six suspects and they participated while in custody in an experiment I was conducting into lie detection for an MSc dissertation in clinical psychology. I was not involved in the criminal investigation and was oblivious to what was really going on behind the closed doors at Sídumúli [Holding] Prison, where most of the interrogations took place. These were to become the biggest murder investigations in Iceland’s history and the Minister of Justice, Ólafur Jóhannesson, sought help from Karl Schütz, a retired, senior, and high profile investigator with the German Federal Criminal Police Office (Bundeskriminalamt; BKA). Karl Schütz dominated the Geirfinnur investigation in the summer and autumn of 1976 and helped the Icelandic judiciary to convict the six defendants by his strong presumption of guilt and forthright assertions. The bodies of the two men were never found and no forensic evidence linked the suspects to the alleged murders.

In early 1997, Saevar Ciesielski contacted me and asked whether I could help him with his pending appeal application before Iceland’s Supreme Court. He was fighting a desperate battle to seek justice for himself and the others. Sadly, I had to turn him down, not only for practical reasons to do with other commitments, but I did not think that the Icelandic judiciary was ready to consider any psychological or other grounds for appeal. At the time, the psychological evidence base for investigating disputed confessions was still modest, but it was growing fast. In the 1990s, interest in the psychology of false confessions had gained momentum after the publication of my first Wiley book, The Psychology of Interrogations, Confessions and Testimony in 1992, followed ten years later by The Psychology of Interrogations and Confessions. A Handbook.

At the end of September 2011, an Icelandic journalist, Helga Arnardóttir, contacted me and asked me to look at three diaries that Tryggvi Leifsson had written while in solitary confinement in Sídumúli Prison in 1976 and 1977. The diaries were never used at trial and their contents were unknown to anybody, apart from Tryggvi, his wife, and his daughter. Reading the diaries had a profound effect upon me; they seemed authentic and Tryggvi came across as very sincere when describing his immense mental suffering during lengthy solitary confinement and compelling claims of innocence. Knowing from my extensive involvement in cases of disputed confessions in the UK, the USA, and elsewhere, and the growing and by now well‐established empirical evidence base, I was in no doubt that the convictions in the Gudmundur and Geirfinnur cases needed to be reviewed, a view I repeated in an Icelandic television documentary on the cases. Within days of the broadcast, Iceland’s Minister of the Interior, Mr Ögmundur Jónasson, contacted me and asked me to act as an expert to a Committee he was setting up to look into the cases. The Committee referred to in this book as the ‘Working Group’ reported its findings in March 2013 and concluded that the confessions of all six convicted persons were wholly unreliable. The Government then established the Icelandic Court Cases Review Commission, which concluded in February 2017 after two year’s work that there were good grounds for appeal regarding the manslaughter convictions and Albert’s conviction for participating in interfering with the crime scene (removal of the body) in the Gudmundur case. The appeal has already been lodged with the Supreme Court.

My experience as a detective in Iceland in the summers of 1975 and 1976 inspired me to become a forensic psychologist after completing my clinical psychology training in 1977. I remained fascinated by the psychology of confessions and in the early 1980s it became one of my principal areas of research interest and endeavour. I never envisaged that almost 40 years later I would become involved in the Gudmundur and Geirfinnur cases as a ‘confession expert’ and able to bring back to Iceland the science that had evolved during that period. This book shows the development of the science behind the psychology of false confessions, building on my two previous books, with minimum overlap, and describes how I have applied the science to the two Icelandic cases.

A large number of people have contributed to the completion and success of this book. Professor Graham Davies, the Series Editor, and my wife Julia have read and commented on drafts of all the chapters. Their comments have been invaluable and improved the quality of the book. They have also provided me with continued support and encouragement throughout. With regard to Parts II and III of the book, Erla Bolladóttir, Sigurthór Stefánsson, and Ragnar Adalsteinsson provided me with important material regarding the Gudmundur and Geirfinnur cases. Sigurthór gave me his hard copy of all the ‘Books of Evidence’. This made it easier for me to read and access the voluminous and complex material. Gudmundur Gudjónsson and Haraldur Steinthórsson suggested helpful background material. Erla, Gudjón, and Albert agreed to further interviews and this strengthened the psychological analysis of their individual cases and gave me deeper insights into their interrogation, confinement, and mental state in the 1970s. Hafthór Saevarsson provided me with his father’s ‘Social Journal’ where I discovered that Saevar had been diagnosed in Denmark in 2010 with attention deficit hyperactivity disorder (ADHD), just over a year prior to his early tragic death at the age of 56. ADHD has featured in my individual analyses of the cases of Saevar, Tryggvi, and Albert. Emma‐Louise Bush assisted with the production of some of the figures. The following people have read and provided comments on one or more of the chapters: Erla Bolladóttir, Gudjón Skarphédinsson, Kristín Tryggvadóttir, Sjöfn Sigurbjörnsdóttir, Tryggvi Rúnar Brynjarsson, Júlia Marinósdóttir, Hafthór Saevarsson, Sigurthór Stefánsson, Helga Arnardóttir, Arndís Sigurdardóttir, Haraldur Steinthórsson, Gudmundur Gudjónsson, Helen Grady, Dr John Pearse, and Professor Susan Young. Cathryn Primrose‐Mathisen, commissioned by Wiley, provided diligent and efficient copy‐editing.

Icelandic names can be difficult and in order to simplify matters, I generally avoid giving middle names, which are very common in Iceland, unless it has a specific purpose (e.g. differentiating people with the same first names). Icelandic names are patronymic, indicating the father of the child and not the historic family lineage (i.e. son or daughter being added to the father’s Christian name, becoming the child’s surname). Therefore, people with the same surnames are not necessarily related (e.g. Gudmundur Einarsson and Geirfinnur Einarsson). It is customary in Iceland to address people by their first name rather than their surname and I generally keep to this tradition. With regard to my own name, I have kept the English spelling, Gisli Gudjonsson, rather than Gísli Guðjónsson, in order not to confuse the reader with regard to the citations of my international publications. I have replaced the consonants ð and þ with ‘d’ and ‘th’ respectively.