Amnesia and crime. How much do we really know?

Claims of amnesia occur frequently after the commission of violent crimes and can have a significant bearing on the outcome of criminal trials. This article considers the relation between amnesia and crime within the broader context of research on memory and amnesia and provides a critical evaluation of current knowledge concerning the issue. Particular attention is paid to the problem of distinguishing between genuine and simulated claims of amnesia. It is suggested that reliable data concerning the nature of amnesic episodes that occur after the commission of a crime are sparse, and that there is as yet little evidence that genuine and simulated amnesia can be distinguished in criminal cases. The results of several laboratory studies are summarized that indicate that feeling-of-knowing ratings distinguished between genuine and simulated amnesia under conditions in which psychologists and psychiatrists did not. In July of 1982, a small item appeared in the back pages of the Toronto Star concerning an ongoing trial in the Ontario Supreme Court ("Accused Killer," 1982). The accused was a 33-year-old man who, several months earlier, had signed a confession in which he admitted to the brutal murder of a 61-year-old man, A striking feature of the confession was the apparent ability of the accused to recall numerous details of the incident. At the time of the trial, however, the defendant claimed that he had made the earlier statement to protect a close friend who otherwise would have become a suspect. In support of this claim, a psychologist testified that the accused never would have remembered the murder in such detail if he had, in fact, committed it. Amnesia, stated the psychologist, follows the commission of a violent crime; a claim of detailed memory for an alleged act of homicide casts doubt upon the possibility that it ever occurred. The psychologist's testimony in this case was surprising. It suggested, at least indirectly, that much is known about the nature of amnesia following a violent crime--so much, in fact, that one could confidently make an absolute statement about an individual case, as had been done in this instance. After all, a psychologist would presumably be reluctant to testify that people cannot remember committing violent crimes unless there is substantial evidence to that effect, because misleading or inaccurate testimony can have profound consequences in