““police officers, like all humans, are subject to a powerful phenomenon that psychologists call confirmation bias. This means that after they have come to a conclusion, especially if it is a conclusion that they have publicly announced (for example, by arresting someone and accusing him of a serious crime), it is very difficult for them to admit that perhaps they have made a terrible mistake. It is much easier and more comfortable for them to convince themselves that they did not make a mistake, and that their initial accusations were correct. Their memories will gladly cooperate in that effort. Even if they are not aware of how it is happening, they might recall nonexistent details to coincide with and corroborate the story they have already begun persuading themselves to believe.””
