For most of human history, eyewitness reports have been used when people are accused of crimes. But in the last few decades, DNA evidence has been developed. This DNA evidence has proven that witnesses are often wrong in their accounts of what took place, as many false convictions that are overturned by DNA were initially made due to inaccurate eyewitness testimony.
Why do eyewitnesses make these mistakes? There are numerous potential reasons.
Memory is malleable
First of all, memory is not static or permanent. It’s not like a video recording. It is malleable and it can change over time. Each time that a witness recalls something, new details could alter their perceptions of that memory. It still seems real, even though it is no longer accurate.
Eyewitnesses may be biased
In some cases, witnesses themselves are biased. Maybe someone has a racial bias against people of a certain ethnic group or background. When asked to pick someone out of a lineup, they may be more likely to choose someone with that background.
Things happen quickly
It’s also worth noting that criminal activity often happens very quickly. The witness doesn’t expect to see the crime take place. If someone witnesses a bank robbery, for instance, they may be very surprised and shocked, in a poor position to see clearly or so focused on a weapon that the bank robber is holding that they don’t really look at that person‘s face. The witness may believe that they remember who robbed the bank after the fact, but the chaos as the robbery happens impacts their memory.
Because eyewitnesses are so often wrong, it’s very important for those who are facing charges to know what legal defense options they have to secure the proper outcome.