Australasian Science: Australia's authority on science since 1938

How Reliable Is an Eyewitness?

Credit: auremar/adobe

Credit: auremar/adobe

By John Dunn

Eyewitness identification of criminals is notoriously unreliable, but a new study based on police records has identified factors that can determine which witnesses are accurate and which are guessing.

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Eyewitness misidentification is the single greatest cause of wrongful convictions in the United States, having played a role in more than 70% of original convictions later overturned by new DNA evidence (www.innocenceproject.org).

This is consistent with a great deal of psychological research using simulated crimes and lineups. This research shows that our memories can be surprisingly fallible – we forget important details of events, even whole events themselves, and we remember things that have never happened. What’s worse, we can make these mistakes even when we seem very confident that our memories are correct.

Findings like these have cast doubt on the reliability of eyewitnesses. Even when witnesses appear to remember something, or someone, strongly and with high confidence, they can still be wrong.

Our research challenges this widespread view. Rather than relying on laboratory studies, we were interested in the reliability of eyewitnesses in actual police lineups and tested two important conclusions drawn from laboratory research: that confidence is not a good guide to accuracy, and that sequential lineups are better than simultaneous lineups.

In a simultaneous lineup, the eyewitness is given all the photos, usually laid out in a grid, and asked to identify the...

The full text of this article can be purchased from Informit.