There is an adage that says “There are three sides to every story: yours, mine, and the truth. And all three are right.” The sentiment behind this saying is that everyone can recall a particular event or circumstance differently, without any one of them being wrong. Differing memories, opinions, or impressions about the same event do not necessarily mean that somebody is lying. Sure, some people tell flat out lies. But most people speak what they believe to be the truth. This phenomenon is especially prevalent in the court system.
Under Minnesota law, acts constituting perjury are those when a person “makes a false material statement not believing it to be true” in specified actions, hearing, proceedings, or writings that required by law to be made under oath or affirmation. Minn. Stat. § 609.48. In other words, perjury is when a person knowingly makes a false statement which relates to the case in hand, under oath, that is capable of influencing the decision of the judge or jury. State v. Burnett, 867 N.W.2d 534, 537 (Minn. Ct. App. 2015). Perjury is a serious offense and is treated accordingly. Those convicted of perjury potentially face a prison sentence of up to 5 years, or if the statement was made during a felony case, 7 years.
What this means is that a witness may have seen or remembered things differently than you, but it does not necessarily mean that they are lying or perjuring themselves. Unless the person knows that the statement is false, but they are making the statement anyway, while under oath, and there is a chance that what they say will affect the proceeding, it’s not perjury.