Burden of Proof

1. Introduction

The burden of proof (Latin: onus probandi) is the obligation to shift the accepted conclusion away from an oppositional opinion to one's own position. The burden of proof is often associated with the Latin maxim semper necessitas probandi incumbit ei qui agit, the best translation of which seems to be: "the necessity of proof always lies with the person who lays charges." This is a statement of a version of the presumption of innocence that underpins the assessment of evidence in some legal systems, and is not a general statement of when one takes on the burden of proof. The burden of proof tends to lie with anyone who is arguing against received wisdom, but does not always, as sometimes the consequences of accepting a statement or the ease of gathering evidence in its defense might alter the burden of proof to its proponents shoulder. The burden may also be assigned institutionally.

He who does not carry the burden of proof carries the benefit of assumption, meaning he needs no evidence to support his claim. Fulfilling the burden of proof effectively captures the benefit of assumption, passing the burden of proof off to another party. However the incidence of burden of proof is affected by common law, statute and procedure.

A "legal burden" or a "burden of persuasion" is an obligation that remains on a single party for the duration of the claim. Once the burden has been entirely discharged to the satisfaction of the Trier of fact, the party carrying the burden will succeed in its claim. For example, the presumption of innocence places a legal burden upon the prosecution to prove all elements of the offense (generally beyond a reasonable doubt) and to disprove all the defenses except for affirmative defenses in which the proof of non-existence of all affirmative defense(s) is not constitutionally required of the prosecution.

It is not to be confused with evidential burden, which is an obligation that shifts between parties over the course of the...