In contrast to the rare circumstances where a burden of proof may shift in a criminal trial, there are several applications of such a concept in civil matters.
Generally speaking, the party that filed the action (be it a criminal complaint by the state’s attorney, or a civil law suit by a private party), has the burden of proof to establish, through evidence, all the requisite elements of a prima facie case. For example, in a case for the offense of tortious battery, the complainant has the burden of proof to establish (1) that there was a specific intent to make contact with the person of another (2) in a harmful or offensive manner, (3) without consent, and (4)a harmful or offensive contact occurred.
If that burden is met, the burden of proof then shifts to the defendant in the case, who now has to plead and prove any defense, by a preponderance of evidence. Often, the defendant raises an affirmative defense, which will have its own elements of proof that must be met by the defendant. Of course, if the defendant raises a counterclaim against the plaintiff, the entire burden of proof shifts to the defendant on the matter of the counterclaim (or third party claim).
Another example of a shifting burden is that in employment discrimination cases. Once the plaintiff has met his or her burden of proof by establishing a prima facie case, the burden of proof shifts to the defendant to show some non-discriminatory reason for its action. If the defendant essentially meets that burden of proof by presenting legitimate reasons for the alleged action, the burden again shifts back to the plaintiff to show that the proffered “legitimate” reasons were pretextual.
A burden of proof generally attaches at the trial or adjudicatory stage. A plaintiff (in a civil case) or a petitioner (in an administrative case), or the state (in a criminal case) need only allege the existence of facts needed to prove each requisite element of the alleged wrong, offense, or crime. The averments or allegations contained therein are presumed to be true during this initial stage. However, at the actual trial, the party then bears the burden of proof to present evidence tending to support or prove the facts alleged in the complaint or petition. Following this presentation of the case in chief, an opposing party may then petition the court to dismiss the case (before it reaches a jury), for failure in meeting a required burden of proof.