Schaffer v. Weast, Supreme Court of the United States, November 14 2005
[ruling that parents who challenge special education programs for not meeting their children's needs bear the burden of proving the programs' inadequacies]. Excerpt:

When we are determining the burden of proof under a statutory cause of action, the touchstone of our inquiry is, of course, the statute. The plain text of IDEA is silent on the allocation of the burden of persuasion. We therefore begin with the ordinary default rule that plaintiffs bear the risk of failing to prove their claims.

The ordinary default rule, of course, admits of exceptions. For example, the burden of persuasion as to certain elements of a plantiff's claim may be shifted to defendants, when such elements can fairly be characterized as affirmative defenses or exemptions. Under some circumstances this Court has even placed the burden of persuasion over an entire claim on the defendant. But while the normal default rule does not solve all cases, it certainly solves most of them. Decisions that place the entire burden of persuasion on the opposing party at the outset of a proceeding—as petitioners urge us to do here—are extremely rare. Absent some reason to believe that Congress intended otherwise, therefore, we will conclude that the burden of persuasion lies where it usually falls, upon the party seeking relief.

Read the full text of the opinon here. Reported in JURSIT's Paper Chase here.