Prosecutor's fallacy is when someone makes a mistake in a court case. It happens because they think that if someone is accused of a crime, then they must be guilty. This is not true, because other things could be true. For example, someone could be innocent, or there could be a mistake in the way that the evidence was found and presented. So, in a court case, it is important to remember that the accused person is innocent until proven guilty, and we need to make sure to have all the facts straight before making any judgement.