There are various ways that evidence is gathered to convict criminals and narrow down suspect lists in South Carolina. However, eyewitness testimonies have been proven to be highly problematic, and their flaws have only become apparent over time. The shortcomings of this widely discredited source of evidence are largely owed to eyewitness cognition and countless mental processes.
Memory and biases
One of the major issues with eyewitness testimonies in criminal defense is that human memory is far from perfect. Witnesses are often asked to recount an intense situation that may have been brief and unclear, even in the moment. It’s easy to forget what happened and change details without realizing it. But it isn’t just eyewitnesses’ memory at play here.
People tend to make assumptions because each eyewitness comes with their own biases and beliefs, whether they realize it or not. How strongly these biases affect their judgment varies from person to person, but some form of prejudice is almost always present to some degree. These preconceived notions have been shown to alter a person’s memory in various ways. For one, if a person sees or hears something that aligns with their understanding of the world, they’re more likely to accept it.
The longer it takes to get the testimony, the witness may remember less of what happened. Key details can slip away as their memory becomes cloudier and more tainted by what the witness personally believes instead of the actual events.
The problem with post-event information
Recent experiments and research have provided evidence that also shows how key post-event information is with eyewitness testimonies. Witnesses may receive new information after the event has occurred that can change the way they understand and contextualize what they saw.
Post-event information may cause a person to see connections that they didn’t form on their own. The witness doesn’t realize that their testimony has been tainted, and the investigators likely don’t realize their influence on the witness.
Powerful evidence has come from the testimonies of credible eyewitnesses, but unfortunately, that’s not always the case. The perfect eyewitness is rare or nonexistent, and innocent mistakes have led to wrongful accusations. Often, it’s out of the eyewitnesses’ hands entirely and falls on the investigators working on the case.