Eyewitnesses to a crime often experience high levels of stress and anxiety. The traumatic nature of the events they witness can impact their ability to recall details accurately. Stress can lead to the narrowing of attention, causing eyewitnesses to focus on certain aspects of the event while neglecting others.
This tunnel vision can result in a distorted or incomplete account of what actually transpired.
Human memory is not infallible. Instead, it is highly susceptible to distortion. Over time, various factors can influence a witness’s recollection of events, including post-event information, suggestions from others and memory consolidation’s cognitive processes. Eyewitnesses may unknowingly incorporate erroneous details into their testimony, leading to inaccuracies.
Lineup and photo array biases
The process of identifying a suspect from a lineup or photo array can introduce significant biases. Eyewitnesses may feel they must choose a person from the presented options, even if the true perpetrator is not among them. Thus, they may identify perpetrators with low levels of confidence.
Research shows that individuals find it hard to identify people from racial or ethnic groups different from their own. This phenomenon, known as the cross-race effect, can result in misidentifications when witnesses need to identify suspects of a different racial background.
A study of almost 350 criminal convictions later overturned by DNA evidence revealed that eyewitness misidentifications had a hand in 70% of them. Recognizing the issues contributing to eyewitness misidentifications minimizes the risk of inaccurate testimony while reducing the chances of wrongful convictions.