If you are accused of a violent crime, the prosecution may produce an eyewitness who allegedly saw the event take place. Maybe someone claims that you brandished a firearm in a bar, for example. You admit to going to the bar in question but you claim you had nothing to do with the incident.
Why is the eyewitness wrong? There are many potential reasons. Maybe you simply look like the person who committed the crime. The lighting in the bar was not good and they couldn’t really tell who they were looking at. Maybe they saw you earlier in the night and have since confused the two memories, assuming you were the one they watched produce the firearm.
One common mistake, though, happens because the eyewitness was not looking at the alleged perpetrator in the first place. Instead, they were looking at the weapon itself.
This happens often enough that it has been deemed the weapon focus effect. It makes it hard for the eyewitness to remember details about the person holding the weapon because they’re just focusing on the weapon during the event. They have a hazy memory of the person’s face and may not have stored memories of identifying information that, under different circumstances, they would have remembered easily.
This could be why they are getting confused about what they saw. They’re trying to piece together their memories of the night in question, but they can’t do so because their brain neglected to store those memories. When this leads to a false accusation, you need to know about all of the defense options you have.