Why are some testimonies unreliable?

Historically, eyewitness testimony has been deemed the cornerstone in resolving both criminal and civil cases. For decades, if a witness could identify a suspect or recount details of an incident, their words had the power to tip the scales of justice. However, is human memory truly a reliable record?

The Irony of Memory in a Judicial Context

Ironically, although eyewitnesses are expected to recall events accurately, studies have shown that the error rate in their testimonies is alarmingly high. This phenomenon is particularly concerning when someone’s life, liberty, or fortune depends on what might be a flawed memory, formed under less than ideal circumstances such as poor lighting or high stress.

The Manipulation of Memories

One of the main issues is the often lengthy period between the event in question and the trial. During this time, memories can be influenced or even manipulated. For example, in a lineup, the presence of a suspect who vaguely matches the initial description of the witness can bias their memory, leading to a convincing yet erroneous identification in court.

Scientific Evidence of Memory Manipulation

The research of Dr. Elizabeth Loftus has been pioneering in demonstrating how memories can be altered. In her experiments, subjects acted as jurors in simulated trials, where the presentation of evidence significantly influenced their decisions. These studies underscore how persuasive presentations can distort memory, leading to manufactured memories that favor one narrative over another.

Debunking Myths About Memory

Contrary to popular belief upheld by old theories like those of Sigmund Freud, memory does not function like a video camera that captures and replays experiences accurately. Human memory is, instead, extremely susceptible to decay and reconstruction. Our brain stores and retrieves information in a way that can be altered over time, affected by new experiences and insights.

The Evolution and Loss of Memory

Scientists now understand that memory evolves. With each recollection, there is an opportunity for it to be modified. This phenomenon is vividly illustrated in studies where participants could not correctly identify a common design, such as a penny, despite their familiarity with the object in everyday life.


Acknowledging the fragility of our memory is crucial, especially in the judicial context, where mistakes can have devastating consequences. It is essential that legal systems understand and mitigate the risks associated with reliance on eyewitness testimonies, always seeking to corroborate these accounts with more tangible and reliable evidence.