Mistaken identity

Mistaken identity is a defense in criminal law which claims the actual innocence of the criminal defendant, and attempts to undermine evidence of guilt by asserting that any eyewitness to the crime incorrectly thought that they saw the defendant, when in fact the person seen by the witness was someone else. The defendant may question both the memory of the witness (suggesting, for example, that the identification is the result of a false memory), and the perception of the witness (suggesting, for example, that the witness had poor eyesight, or that the crime occurred in a poorly lit place).

Because the prosecution in a criminal case must prove the guilt of the accused beyond a reasonable doubt, the defendant must convince the jury that there is reasonable doubt about whether the witness actually saw what he or she claims to have seen, or recalls having seen. Although scientific studies have shown that mistaken identity is a common phenomenon, jurors give very strong credence to eyewitness testimony, particularly where the eyewitness is resolute in believing that their identification of the defendant was correct.

Researchers like Elizabeth Loftus have challenged eyewitness testimony based on the fact that people's memory can be distorted. In her study she questioned eyewitnesses about a videotape of a car accident. Witnesses were asked "How fast were the cars going when they hit each other?" However, some witnesses were asked the same question with the verb "hit" replaced by the verb "smashed". Those who were asked the question with "smashed" as the verb said the cars were moving faster than those who were asked the same question with the verb "hit." Additionally, when asked if there was broken glass at the scene, those who heard "smashed" were more likely to say there was than those who heard "hit." There was no broken glass in the videotape. Hers is only one example of studies that show memory can be susceptible to distortions.

With genetic fingerprinting and DNA evidence now commonplace, many convictions based on eyewitness testimony are being re-examined. According to statistics, over 75% of the cases of DNA exonerations have involved mistaken eyewitness identification.

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