Our minds are constantly taking in information, then filtering it through our various experiences and biases so that it makes sense in our lives. That's why several eyewitnesses to the same event often report different stories. You may see a two-car collision and recall how the blue car broadsided the red car after blowing through a stop sign, because that once happened to you, while someone else may emphasize the fact that the driver of the red car was yakking on her phone, because that's a pet peeve of hers. One memory researcher explained it this way: We all have personal narratives that are formed by our beliefs and values. Our minds take our memories and create explanations for what we've seen or heard based on those beliefs and values [source: Hayasaki].
Filtering may be behind some of the numerous inconsistencies in eyewitness reports of crimes, such as the 2014 tragedy in Ferguson, Missouri. In that incident, a white police officer (Darren Wilson) shot and killed an unarmed, 18-year-old black man (Michael Brown). Some witnesses said Wilson charged at Brown first. Others said Brown never moved toward Wilson. Some witnesses claimed Brown put his hands up in the air but Wilson shot him anyway; others said Brown never put his hands up or only put them briefly [source: New York Times].