Amina Memon is a Professor in Psychology and director of the Royal Holloway Eyewitness Research Group. She has 25 years of research and practice in the field of investigative interviewing and eyewitness memory. She is a trustee for the Centre for the study of Emotion and the Law.
Using the Furundzija case as an insight into the relationship between law and psychology, this article focuses on the need for those that work on the legal field to take into account the research developments around Post Traumatic Stress Disorder (PTSD). Challenging the claim that the credibility of witness evidence is compromised by PSTD, this article stresses the need for awareness of the complexity around determining the reliability of the memory of a witness with PTSD. It also highlights the distinction between the reliability (accuracy) of a witness account and its credibility (whether it is true or not). These conclusions are highly relevant for asylum and refugee cases where traumatic events on a witness testimony are dismissed as not credible due to inconsistencies or to changes in the details of a witness account.
In December 1998, the International Criminal Tribunal for the Former Yugoslavia (ICTY) sentenced the local commander of the Croatian defence council, a Bosnian Croat named Furundzija, to ten years imprisonment for the confinement and repeated rape of a Muslim woman by his subordinates. Furundzija was found guilty as a co-perpetrator of torture and of aiding and abetting in outrages upon personal dignity, including rape. Upon completion of the trial in June 1998, Furundzija brought a motion to set aside the evidence of one witness A, or alternatively for a retrial, on the basis that he had been prejudiced by the non-disclosure of witness A’s rape counseling records. The court allowed the motion and ordered the disclosure of any relevant documents and subjected all prosecution witnesses, including witness A, to cross-examination with respect to these documents.
The proceedings concerning the reliability of witness A’s evidence hinged heavily on the assumption that quality of evidence may have been compromised as a result of post-traumatic stress disorder (PTSD). In November 2008, witness A was subjected to the ordeal of giving further testimony. The reliability of witness A’s memory and the possible diagnosis, and implications, of PTSD became central issues as did the credibility of testimony from victims of trauma generally. The prosecutor in his submission to the Appeals Chamber stated: ‘any evidence relating to the mental health or psychological state of witness A generally would have been material to his [the appellant’s] case since his defense had been conducted on the basis that Witness A’s memory was flawed.’ The first issue concerned the admission of medical and psychological reports of treatment and diagnosis of witness A.
The Trial Chamber accepted the argument of the defense regarding the relevance of these documents and permitted a reopening of the trial on the issue of the ‘medical, psychological or psychiatric treatment or counselling received by witness A’ (F 338). The defense had already offered expert evidence as to the diagnosis of witness A as suffering from PTSD and its implications for the reliability of witness A’s evidence. What is interesting here is that PTSD was introduced as evidence against a complainant. Witness A was adamant that she did not suffer from PTSD, nor had she received psychological treatment for it. The defense’s expert witness claimed that witness A’s rejection of the diagnosis and her ‘denial’ of the symptoms of PTSD were typical of sufferers of chronic PTSD. The defence expert argued that ‘the more trauma, the worse the memory’ (F 340). In other words, the higher the degree of trauma suffered, the more unreliable the memory (F 340). This line of argument, however, is unsubstantiated by the empirical literature.
To begin with, let us define post-traumatic stress disorder. The concept of trauma embodied in the Diagnostic and Statistical Manual (DSM-V) of Mental Disorder (American Psychiatric Association, 2000, p. 467-468) has two parts, and only if people meet both parts do they count as trauma survivors. One, criterion A2, requires that the person must have experienced extreme fear, horror, or helplessness as the event was occurring. The other, criterion A1, certifies three groups of people as potentially eligible for the diagnosis of PTSD: direct recipients of serious threat or harm, such as rape victims or combat veterans; those experiencing vicarious exposure to the trauma experienced by others, such as bystanders at a drive-by shooting; and those who are ‘confronted with’ information about threats to others, such as horrified television viewers of the 9/11 terrorist attacks. What distinguishes PTSD from other anxiety disorders is that the traumatic event is of monumental significance and violates formerly held concepts of safety.
In line with the scientific literature on PTSD and memory, the prosecution expert in the Furundzija case challenged the scientific basis of the evidence that PTSD, and in particular, that severity of PTSD led to a more unreliable testimony. The prosecution were correct in making this challenge, but what the tribunal did not do is explain why they rejected the defense arguments, neither did they set any precedents. The testimony provided by the experts in Furundzija did not provide much guidance and for this reason it is important to examine more fully the reliability of testimony from an individual who may have PTSD or one who has received a PTSD diagnosis.
Each eyewitness has a unique reaction to a traumatic event, and response to trauma is not only influenced by the personality and coping style but also by language and culture (Herlihy et al. 2012). Importantly, memories of traumatic events are not unlike memories of non-traumatic events (Brewin, 2011). Both types of memories are subject to decay over time and with both types of memory, we reconstruct our reports and we may fill in gaps with details that ‘fit’ the story. This does not necessarily mean our memories are embellished with false details. Our memories for details may change over time and this fact, together with the way in which a witness is questioned, may result in discrepancies in what is reported on different occasions.
The prosecution in the Furundzija case were correct in concluding that the scientific literature shows that individuals suffering from PTSD can remember events accurately. Some laboratory studies find that memory reports relating to traumatic events tend to be accurate when it comes to the central details relating to an event or plot, but there may be more discrepancies relating details in the ‘periphery’ which may include things happening in the background and smaller details (Herlihy and Turner, 2006, Herlihy et al., 2007).
Although they may not always be able to retrieve their memories, PTSD sufferers generally have access to specific details of events because traumatic memories are associated with more vivid and detailed imagery than ordinary memories. Some research suggests that trauma survivors who have suffered more severely may display a heightened accuracy in their memory for details associated with the trauma. In addition, memories of trauma can change during the course of PTSD treatment or therapy, presumably due to a change in the severity of PTSD symptoms (see Brewin, 2011). For example, re-living the trauma, a technique commonly used in treatment of PTSD, can result in a gradual decline in the frequency of intrusions and associated distress (Ehlers, Hackmann and Michael, 2004). This may reduce one type of memory associated with PTSD, namely over general memory, a type of memory that may be a result of trying to suppress memories of trauma.
The issue of stability of trauma memory is a key one and this is directly relevant to the issue of whether memories remain consistent or not over time. To sum up so far, PTSD brings with it both an enhanced and impaired memory for a traumatic event. This makes it extremely complex when assessing the reliability of a given witness’s memory. Added to this is the fact that reliability is often confused with credibility.
Reliability refers to accuracy of a witness’s memory whereas credibility is whether or not a witness appears to be speaking the truth or whether they come across as honest. A witness may come across as credible but be completely unreliable or inversely, a witness may have a reliable memory but may not appear credible. The scientific literature shows there are few reliable indicators of credibility and yet there is the mistaken belief among decision-makers that they can tell when someone is speaking the truth or lying. For example, decision makers may invoke factors such as delayed disclosure, inconsistencies in accounts, and a calm or overly emotional demeanor on the part of a female applicant to justify suspicion regarding allegations of rape. Advocates may also adopt questioning strategies with the aim of the making the witness appear less credible. For example, they may ask very specific questions which a witness cannot answer confidently, thus giving the impression that the witness is not credible (Fisher et al. 2012). This undermines the reliability of the witness and does not serve justice.
Furundzija was the first trial in the international criminal courts in which the credibility of the defendant was attacked by virtue of the witness’s psychological and neurological state. In other words, the reliability of the memory of the complainant was questioned by putting her credibility into doubt. However, there is an inherent contradiction in the argument here because the Trial Chamber is assuming a link between reliability and credibility and is erroneously conflating these terms. Judges and legal professionals are very suspicious of changes in testimony because they do not understand that a witness can be reliable but not credible or unreliable but credible (Fisher, Brewer, & Mitchell, 2009).
It is useful for legal institutions to understand why discrepancies in witness accounts may occur. People who suffer from trauma or have experienced stressful event may be more likely to try and make sense of what has happened to them. In doing so, events which may have previously been seen as irrelevant may increase in importance over time and may be labeled differently too (Engelhard et al. 2008). Events which may have seemed irrelevant at the time they occurred may have increased in importance and be labeled differently.
Discrepancies in memory reporting (for both traumatic and non-traumatic events) are not merely a function of questioning strategy, but they can arise as a result of genuine memory problems. One common occurrence is a confusion about the source of a memory. For example, in their study of memory consistency for traumatic events in Dutch soldiers, Engelhard et al. (2008) discuss how when Dutch soldiers received new information about deployment to Iraq, it sometimes gets inadvertently incorporated into the memories of their experiences of when they were in Iraq. These kinds of errors in memory can reduce the accuracy of a witness and where it is suspected this may be the case, legal institutions are justified in questioning the reliability of a witness’s evidence. However, these types of errors do not necessarily mean the witness is engaging in deceit or deliberately trying to mislead the court (the latter being an issue of credibility).
In a recent review of the deception literature, Hartwig & Bond (2011) suggest that the behavioural differences between liars and truth-tellers are very small, because people are skilled at deception and both liars and truth-tellers work at creating a credible impression. Thus, we need to adopt strategies to elicit cues and increase sender transparency.
However, Herlihy’s work suggests this may not work (see Herlihy et al. 2012). Herlihy and colleagues examined the testimony of individuals seeking asylum as a result of abuse or fear of persecution in their home country. Here we have a situation where victims and witnesses may be coerced into concealing facts. Moreover, the stakes are high for asylum seekers for whom it is very important that they are believed. It is because of this that asylum seekers may deliberately attempt to appear credible and use strategies to achieve this goal. Herlihy et al. suggest that asylum seekers may add details to a predominantly truthful statement to strengthen their case, or omit details for fear of safety or to protect others. Witnesses may not come forward and give evidence if they have doubts about whether they will be believed. Some evidence suggests that in a (non-asylum seeking) sample of rape victims, beliefs that one’s memory about the rape is inadequate was associated with a reduced likelihood of pursuing a conviction (Hardy, Young & Holmes, 2009).
Educating judges and jurors about the different ways in which a witness may respond to trauma and the complex effects on testimony may reduce reliance on witness demeanor in making decisions. An improved understanding of the effects of trauma on witness memory and testimony, with a clear distinction between factors that may affect reliability and factors that may affect credibility, would not only aid the courts but ensure that evidence from survivors of sexual violence can be heard without prejudice.
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Prosecutor v. Anto Furundzija - Case No. IT-95-17/1-T. ‘Judgement’. 10 December 1998. Retrieved 6 Jul 2012.
Prosecutor v. Furundzija, Decision (on Defence Motion to Strike testimony of Witness A), No. IT-95-17/1-T (July 16, 1998).