Memory for murder. A psychological perspective on dissociative amnesia in legal contexts

The Memory-Undermining Effect of Simulated Crime-Related Amnesia and Its Legal Implications: a Review

Pretending to suffer from amnesia for a mock crime has been shown to lead to memory impairments. Specifically, when people are asked to give up their role of simulators, they typically recall fewer crime-relevant details than those who initially confess to a crime. In the current review, we amassed all experimental work on this subject and assessed the characteristics of the memory-undermining effect of simulated amnesia for a crime procedure (i.e., crime stimuli, simulating amnesia instructions, memory tests, and memory outcomes). We specifically focused on the effect that crime-related amnesia claims may have on offenders’ final memory reports. Our review showed that simulators who initially claimed amnesia might paradoxically experience some sort of forgetting pertaining to crime-related information. This issue could likely lead to legal complications that need be taken into account in crime-related amnesia cases.

Do reminders of the crime reverse the memory-undermining effect of simulating amnesia?

Research shows that simulating amnesia impairs actual memory for a mock crime. Lack of rehearsal has been suggested as the most likely explanation for this finding because feigning amnesia is linked to reduced thinking about the offence. We investigated whether reminders about the crime could reverse the memory-undermining effect of simulation. In two studies, participants watched a video of a violent crime. After, they were asked to either simulate amnesia or confess the crime. During the week between the first and second memory test phase, participants were provided with reminders of the crime in two different modalities. In Study 1 (pilot), participants received frames of the mock crime video via WhatsApp. Findings showed that such reminders did not enhance ex-simulators' memory. In Study 2, participants were asked to put sequences of the mock crime in the right order. This latter modality led to enhanced memory for the offence in simulating participants. Theoretical and practical implications of our findings for the legal field are discussed.

The Detection of Malingered Amnesia: An Approach Involving Multiple Strategies in a Mock Crime

The nature of amnesia in the context of crime has been the subject of a prolonged debate. It is not uncommon that after committing a violent crime, the offender either does not have any memory of the event or recalls it with some gaps in its recollection. A number of studies have been conducted in order to differentiate between simulated and genuine amnesia. The recognition of probable malingering requires several inferential methods. For instance, it typically involves the defendant's medical records, self-reports, the observed behavior, and the results of a comprehensive neuropsychological examination. In addition, a variety of procedures that may detect very specific malingered amnesia in crime have been developed. In this paper, we investigated the efficacy of three techniques, facial thermography, kinematic analysis, and symptom validity testing in detecting malingering of amnesia in crime. Participants were randomly assigned to two different experimental conditions: a group was instructed to simulate amnesia after a mock homicide, and a second group was simply asked to behave honestly after committing the mock homicide. The outcomes show that kinematic analysis and symptom validity testing achieve significant accuracy in detecting feigned amnesia, while thermal imaging does not provide converging evidence. Results are encouraging and may provide a first step towards the application of these procedures in a multimethod approach on crime-specific cases of amnesia.

Feigning Amnesia Moderately Impairs Memory for a Mock Crime Video

Previous studies showed that feigning amnesia for a crime impairs actual memory for the target event. Lack of rehearsal has been proposed as an explanation for this memory-undermining effect of feigning. The aim of the present study was to replicate and extend previous research adopting a mock crime video instead of a narrative story. We showed participants a video of a violent crime. Next, they were requested to imagine that they had committed this offense and to either feign amnesia or confess the crime. A third condition was included: Participants in the delayed test-only control condition did not receive any instruction. On subsequent recall tests, participants in all three conditions were instructed to report as much information as possible about the offense. On the free recall test, feigning amnesia impaired memory for the video clip, but participants who were asked to feign crime-related amnesia outperformed controls. However, no differences between simulators and confessors were found on both correct cued recollection or on distortion and commission rates. We also explored whether inner speech might modulate memory for the crime. Inner speech traits were not found to be related to the simulating amnesia effect. Theoretical and practical implications of our results are discussed.

Testing Claims of Crime-Related Amnesia

Many violent offenders report amnesia for their crime. Although this type of memory loss is possible, there are reasons to assume that many claims of crime-related amnesia are feigned. This article describes ways to evaluate the genuineness of crime-related amnesia. A recent case is described in which several of these strategies yielded evidence for feigned crime-related amnesia.

Memory Interventions in the Criminal Justice System: Some Practical Ethical Considerations

In recent years, discussion around memory modification interventions has gained attention. However, discussion around the use of memory interventions in the criminal justice system has been mostly absent. In this paper we start by highlighting the importance memory has for human well-being and personal identity, as well as its role within the criminal forensic setting; in particular, for claiming and accepting legal responsibility, for moral learning, and for retribution. We provide examples of memory interventions that are currently available for medical purposes, but that in the future could be used in the forensic setting to modify criminal offenders' memories. In this section we contrast the cases of (1) dampening and (2) enhancing memories of criminal offenders. We then present from a pragmatic approach some pressing ethical issues associated with these types of memory interventions. The paper ends up highlighting how these pragmatic considerations can help establish ethically justified criteria regarding the possibility of interventions aimed at modifying criminal offenders' memories.

'Drugs That Make You Feel Bad'? Remorse-Based Mitigation and Neurointerventions

In many jurisdictions, an offender's remorse is considered to be a relevant factor to take into account in mitigation at sentencing. The growing philosophical interest in the use of neurointerventions in criminal justice raises an important question about such remorse-based mitigation: to what extent should technologically facilitated remorse be honoured such that it is permitted the same penal significance as standard instances of remorse? To motivate this question, we begin by sketching a tripartite account of remorse that distinguishes cognitive, affective and motivational elements of remorse. We then describe a number of neurointerventions that might plausibly be used to enhance abilities that are relevant to these different elements of remorse. Having described what we term the 'moral value' view of the justification of remorse-based mitigation (according to which remorse-based mitigation is justified insofar as mitigation serves as a deserved form of response to the moral value of the offender's remorse), we then consider whether using neurointerventions to facilitate remorse would undermine its moral value, and thus make it inappropriate to honour such remorse in the criminal justice system. We respond to this question by claiming that the form of moral understanding that is incorporated into a genuinely remorseful response grounds remorse's moral value. In view of this claim, we conclude by arguing that neurointerventions need not undermine remorse's moral value on this approach, and that the remorse that such interventions might facilitate could also be authentic to the recipient of the neurointerventions that we discuss.

The neuroscience of face processing and identification in eyewitnesses and offenders

Humans are experts in face perception. We are better able to distinguish between the differences of faces and their components than between any other kind of objects. Several studies investigating the underlying neural networks provided evidence for deviated face processing in criminal individuals, although results are often confounded by accompanying mental or addiction disorders. On the other hand, face processing in non-criminal healthy persons can be of high juridical interest in cases of witnessing a felony and afterward identifying a culprit. Memory and therefore recognition of a person can be affected by many parameters and thus become distorted. But also face processing itself is modulated by different factors like facial characteristics, degree of familiarity, and emotional relation. These factors make the comparison of different cases, as well as the transfer of laboratory results to real live settings very challenging. Several neuroimaging studies have been published in recent years and some progress was made connecting certain brain activation patterns with the correct recognition of an individual. However, there is still a long way to go before brain imaging can make a reliable contribution to court procedures.

Let's use those tests! Evaluations of crime-related amnesia claims

Suspects awaiting trial often claim that they cannot remember important parts of their violent crimes. It is not unusual that forensic experts readily accept such claims and interpret them in terms of dissociative amnesia or, more specifically, a "red-out". This interpretation hinges on the assumption that heightened levels of stress implicated in violent crimes interfere with memory. We argue that the notion of red-out is a priori not plausible and that alternative interpretations-primarily malingering and substance-induced organic amnesia-should be considered and ruled out first before concluding that memory loss is dissociative in nature. We illustrate our point with four cases that superficially have the contours of red-out tragedies. We believe that, in such cases, neuropsychological tests and/or psychopharmacological information on dose-response relationships can assist forensic experts to exclude malingering or substance-induced amnesia. There is no reason for not using tests and tools from neuropsychology and psychopharmacology.

Evaluating amnesia for criminal behavior: a guide to remember

This article provides a guide that is important to remember in evaluating a criminal defendant's amnesia claim. Important concepts to understand regarding memory formation, memory systems, proposed causes of amnesia, reasons why amnesia claims may be true or false, and important strategies to implement as part of the evaluation process are reviewed. Structured assessment approaches are critical components of amnesia evaluations and generally require detailed questioning, review of collateral records, medical and neurologic workups, psychological testing, neuropsychological testing, and specific malingering assessments.

A study of amnesia in homicide cases and forensic psychiatric experts' examination of such claims

About one third of defendants in homicide cases claim amnesia during the time of their alleged act. Examining the authenticity of claimed amnesia is a special challenge for forensic experts. Because the experts' conclusions have legal implications, it is useful to study the characteristics of defendants who claim amnesia regarding a homicidal act and how forensic experts assess these defendants' claims. The forensic psychiatric reports from 2001 to 2007 on 102 Norwegian defendants charged with homicide were assessed quantitatively with a structured rating form. Due to multiple comparisons p of .003 was chosen. Twenty-six defendants claimed partial and 17 claimed total amnesia. No significant differences in the characteristics of the defendants were found between the partial, total, and no amnesia claiming groups. Claims of partial or total amnesia did not change the procedures and content of the forensic experts' examination. A memory test was applied in only one case. Despite the seriousness of the crime and the difficulty of assessing amnesia, the experts did not apply psychological testing of memory function or appropriate tests of possible malingering. Guidelines or standardized procedures for evaluation of defendants who claim amnesia should be developed. This could eventually contribute to more reliable and valid evaluations by forensic experts and increase the probability of just court outcomes.

A comparison of memory for homicide, non-homicidal violence, and positive life experiences

Defendants commonly claim amnesia for their criminal actions especially in cases involving extreme violence. While some claims are malingered or result from physiological factors, other cases may represent genuine partial or complete amnesia resulting from the psychological distress and/or extreme emotion associated with the perpetration of the crime. Fifty Canadian homicide offenders described their memories of their homicide, a non-homicide violent offense, and their most positive adulthood life experience. Self-reported and objective measures of memories for these events revealed that homicides were recalled with the greatest level of detail and sensory information. Although dissociative tendencies were associated with a self-reported memory loss, objective measures of memory quality did not reflect this perceived impairment, suggesting a failure of meta-memory. Recollections of positive life events were superior to those of non-homicidal violence, possibly due to greater impact and meaning attached to such experiences. Findings suggest that memory for homicide typically is enhanced by the powerful emotion associated with its perpetration.

Amnesia for violent crime among young offenders

Amnesia for the perpetration of violent offences is an important issue in medico-legal proceedings. Previous studies of amnesia have mainly relied on selected groups of unconvicted offenders, which raises the question of how reliable the findings are. The purpose of this study was to examine the prevalence and phenomenological qualities of amnesia in violent offenders. In semi-structured interviews with 105 young offenders convicted of serious violence, 20 (19%) reported partial amnesia for their offence and only one (1%) reported complete amnesia. Amnesia was associated with high alcohol intake, emotional ties to the victim, and cognitive processing during the assault. Complete amnesia for violent crime appears to be less frequent than suggested by previous reports using unconvicted samples. The findings have implications for the clinical assessment of claimed amnesia for violent crime and are potentially of medico-legal significance.

Claims of amnesia for criminal offenses: psychopathology, substance abuse, and malingering

The forensic psychiatric examiner often encounters defendants who deny memory for their offense. Past research proposes a variety of factors to account for offense amnesia. To date there have been few systematic studies of offense amnesia in relation to psychiatric diagnosis, either alone or in combination with other known factors such as substance use and malingering. We studied 53 pretrial felony defendants who had been referred for psychiatric examination; 40% claimed amnesia for their offense. Examinees with psychotic disorders in general, and schizophrenia in particular, were relatively less likely to claim amnesia than were examinees with other diagnoses. Substance use at the time of the offense and associated substance use disorder diagnoses were positively associated with offense amnesia. Malingering diagnosed by general clinical criteria was a poor predictor of amnesia claims. These data suggests that two prominent reasons for referral for forensic psychiatric evaluation include the presence of psychotic symptoms and claims of amnesia for the offense.

"I'm sorry I did it... but he started it": a comparison of the official and self-reported homicide descriptions of psychopaths and non-psychopaths

This study concurrently examined the characteristics of violent actions (homicides) and the manner in which the violent acts are described by the perpetrators. N=50 offenders incarcerated for homicide were classified as psychopathic or non-psychopathic, according to the Psychopathy Checklist-Revised (Hare, 1991, 2003). The instrumentality/reactivity and major details of their violence were coded from the official files. Further, the offenders' own accounts were coded on the same variables by independent raters. Results indicated that whereas psychopaths were far more likely than their counterparts to have perpetrated primarily instrumental homicides, this difference disappeared when examining the self-report descriptions. Overall, although psychopaths and non-psychopaths both tended to exaggerate the reactivity of their homicides, psychopaths did so to a greater degree. Psychopaths also were more likely to omit major details of their offenses.

What violent offenders remember of their crime: empirical explorations

Little systematic evidence is available about how violent offenders remember and think about their violent crimes. The general aim of this article is to selectively review a range of different 'types' of memory disturbance and their risk factors, in an attempt to draw together different strands of research concerning memories of offending that might usefully be considered together for clinical purposes. A selective review of psychiatric or psychological studies related to amnesia, intrusive memories, posttraumatic stress disorder (PTSD), ruminations, and pleasurable memories was performed. The body of research on amnesia in relation to violent crime is relatively small and is subject to significant limitations. The empirical base of studies identifying intrusive memories arising from violent crime is also very limited, with no previous published study primarily focusing on description of the form and content of intrusive memories related to acts of violence in a population of violent offenders. A small number of studies have investigated PTSD directly arising from the commission of a violent or sexual crime, in those with mental illness. No published studies that investigated the presence of ruminations related to violent offending were identified. No systematic comparative studies were identified that described the form and content that positive memories of non-sexual violence might take. Relevant phenomenological reports from extreme populations raise concerns about selection bias. A memory-based approach to eliciting descriptions of violent offending may elicit clinical information relevant to violence risk assessment and therapeutic interventions within forensic settings.

Dissociation and violence: a review of the literature

Violent acts are sometimes committed by people who do not normally appear violent or aggressive. This simple observation and others have led some to speculate about a relationship between dissociation and violence. However, no systematic review of the literature has so far been published. To address this gap, studies assessing the prevalence of dissociation among violent individuals, and violence among highly dissociative persons, are reviewed. Possible links between dissociation and violent behavior are explored. It is concluded that dissociation predicts violence in a wide range of populations and may be crucial to an understanding of violent behavior. There is a clear need, however, for large scale, well-designed studies using reliable structured instruments in a number of areas reviewed. Recommendations for clinical applications include the routine screening of offenders for dissociative disorders and adequate consideration of dissociation and dissociative disorders in the development and implementation of violence treatment and prevention programs.