 For example, if a judge believes that the evidence in question was obtained illegally, the judge can rule that it not be shown in court.It could also refer to a prosecutor improperly or intentionally hiding evidence that does not go with their case (their theory of what happened) and could suggest or prove to the judge or jury that the defendant is not guilty or that (s)he is legally obligated to show the defense.In the latter case, this would be a violation of the 5th amendment to the United States Constitution.