Burden of Proof

The duty to prove disputed facts. In civil cases, a plaintiff generally has the burden of proving his or her case. In criminal cases, the government has the burden of proving the defendant's guilt.

Additional Sources

Answers.com

The responsibility of proving a disputed charge or allegation.

Duhaime Legal Dictionary

A rule of evidence that imposes on a participant in a court case the initial obligation to prove a certain thing or the contrary will be assumed by the court.

FindLaw

The responsibility of producing sufficient evidence in support of a fact or issue and favorably persuading the trier of fact (as a judge or jury) regarding that fact or issue.

Law.com Dictionary

The requirement that the plaintiff (the party bringing a civil lawsuit) show by a "preponderance of evidence" or "weight of evidence" that all the facts necessary to win a judgment are presented and are probably true. In a criminal trial the burden of proof required of the prosecutor is to prove the guilt of the accused "beyond a reasonable doubt," a much more difficult task. Unless there is a complete failure to present substantial evidence of a vital fact (usually called an "element of the cause of action"), the ultimate decision as to whether the plaintiff has met his/her burden of proof rests with the jury or the judge if there is no jury. However, the burden of proof is not always on the plaintiff. In some issues it may shift to the defendant if he/she raises a factual issue in defense, such as a claim that he/she was not the registered owner of the car that hit the plaintiff, so the defendant has the burden to prove that defense. If at the close of the plaintiff's presentation he/she has not produced any evidence on a necessary fact (e.g. any evidence of damage) then the case may be dismissed without the defendant having to put on any evidence.

Lect Law Library

The obligation of a party to prove his allegations during a trial. Typically, the plaintiff must prove whatever allegations he included in his complaint in order to win his case. The defendant is given the opportunity to submit evidence to rebut the plaintiff's case. To rebut generally means to contest a statement or evidence presented by another.

Legal-Dictionary.org

Responsibility of party in a lawsuit to persuade a judge or jury that the evidence proves its side of the case.

The Free (Legal) Dictionary

A duty placed upon a civil or criminal defendant to prove or disprove a disputed fact.

Burden of proof can define the duty placed upon a party to prove or disprove a disputed fact, or it can define which party bears this burden. In criminal cases, the burden of proof is placed on the prosecution, who must demonstrate that the defendant is guilty before a jury may convict him or her. But in some jurisdiction, the defendant has the burden of establishing the existence of certain facts that give rise to a defense, such as the insanity plea. In civil cases, the plaintiff is normally charged with the burden of proof, but the defendant can be required to establish certain defenses.

Wikipedia

The burden of proof (Latin: onus probandi) is the obligation to shift the assumed conclusion away from an oppositional opinion to one's own position. The burden of proof may only be fulfilled by evidence.

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 which 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 defence might alter the burden of proof its proponents shoulder. The burden may also be assigned institutionally.