When a crime occurs, the prosecution will often rely on the testimonies of people who were there when it happened. The police will ask them questions about the crime before they take the stand and tell their story. They will try to recall the event from their memory, but the human memory is not always reliable.
Eyewitnesses usually believe their story is the truth; thus, they can provide very convincing narratives in the courtroom. Because of eyewitness errors, the truth gets lost in perspective and the reconstruction of their memories.
Why do eyewitness errors occur?
The capacity to store short-term and long-term memory varies from person to person, but a person rarely recalls every exact detail of an event. People even have difficulty remembering an actor from a movie. A crime can be a highly stressful and traumatic experience for anyone, and these emotions tend to affect cognition. Sometimes, an eyewitness will use what they believe to be true to fill in the missing pieces of their narrative.
An eyewitness will need to provide a cohesive and detailed testimony of the crime by piecing together information from their mind. The problem is that memories change in the mind because personal beliefs and stored knowledge influence how people remember things.
The information an eyewitness obtains after the crime may also play a role in restructuring their memory. An investigator may ask the eyewitness what weapon the accused used when there was no weapon at all. Suddenly, the eyewitness remembers a knife or a gun.
How significant is the impact of eyewitness errors?
Eyewitness errors can lead to wrongful convictions. Their false accounts of the crime can send an innocent person to jail.