In any type of legal action, including family law matters, a burden of proof must be met in order to “win” a case. In the U.S., there are three basic standards of proof:
In most civil cases, it is the plaintiff’s job to prove his point – that is, the person bringing the action must prove their story. In criminal cases, the defendant is not required to present a defense if the plaintiff cannot meet the standard of proof, thus the phrase “innocent until proven guilty”.
In family court, however, there is no “innocence or guilt” and both parties typically present their cases before any ruling is made. Typically, the two sides will present contradicting positions on a matter like property distribution, alimony or child custody. The judge then must decide how to render a fair judgment in the circumstances.
There are, however, some exceptions to this scenario:
Sometimes, a defendant will admit to the behavior or actions alleged but contend that the actions were justifiable. This is known as an affirmative defense. The most common courthouse example of this would be a defendant who claimed self-defense in a murder trial but there are other examples as well. A defendant/respondent being sued for divorce on the grounds of abandonment, for instance, could justify leaving the marriage if the other spouse was abusive. This would be considered an affirmative defense and it would be up to the defending spouse to prove the allegation of abuse.
There are instances in family court in which one side must “prove” something in the traditional sense too. If a father files a motion to modify custody several years after the divorce, the law will require him to prove, by a preponderance of the evidence, that there are such changed circumstances that a modification of custody is in the child’s best interests. If he cannot prove the change of circumstances, his motion will be denied.