Crime Library: Criminal Minds and Methods

The Art of Forensic Psychology

A Friend of the Court

Ronald Cotton
Ronald Cotton

"Jane" was raped by a man whom she saw from several different angles.  She managed to escape and she gave police details for a composite drawing.  It was circulated and people called in with names of men it resembled.  Ronald Cotton heard that his name had been called, so he went to the police station to set them straight about his innocence.  Instead, he was arrested and placed in a line-up.  To his surprise, Jane identified him as the man from the line-up and from a photo spread.  She was strongly encouraged by police when she made her choice, increasing her confidence.  Cotton went to trial and was convicted, but DNA evidence a decade later exonerated him and implicated another man--a man who was in prison for another rape and who admitted he had done it.  He looked nothing like Cotton.  While Jane had to admit that she had been wrong and she now knew what the real perpetrator looked like, she continued to have a persisting memory of Ronald Cotton as her rapist.

The degree to which eyewitness memory can be influenced by suggestion is the first documented case in the history of forensic psychology, occurring in the late nineteenth century in Germany.  Despite its long history, it is still not easy for psychologists to direct the court's attention to this issue, because judges often believe that juries can decide such issues for themselves.  In other words, assessing witness memory appears to many in the judiciary as a phenomenon that requires no expert explanation.  Nevertheless, from the findings among those psychologists who focus on it, eyewitness memory is clearly an issue that anyone who cares about justice should recognize.

It's estimated that each year, 4,500 wrongful convictions are based on mistaken eyewitness identification, which generally grows out of faulty memory encoding.  It is the most common cause of wrongful convictions.  In part, this is due to the exposure to misinformation after an event, which has been shown to lead to erroneous reports of that information.  (A person sees the theft of a hammer, for example, but someone tells him she saw the thief take a screwdriver, so when he responds to questioning, he says that a screwdriver was taken.) 

This is called the misinformation effect, and the errors result from erroneous information to which a person is exposed during the process of acquiring, retaining or retrieving the subject of the memory: the unconscious acceptance of suggested information affects how new memories get formed.  In other words, misleading or new information can interfere with how we may remember an event and can supplant our own memory with information that is not our memory at all.  In studies, it was found that subjects who reported erroneous information from the misinformation effect retrieved this "memory" as quickly as they did an actual memory and felt just as confident that they had had the experience that they "remembered." That should be of concern to anyone involved in the legal system.

Elizabeth Loftus
Elizabeth Loftus

Research indicates the memory is quite malleable.  Research psychologist Elizabeth Loftus says that "many influences can cause memories to change or even be created anew."  We cannot rely on our memories to be accurate, no matter how confident we may be, since even confident people can be mistaken -- to great damage done to innocent people's lives.

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