BURDEN OF PROOF, or ONUS PROBANDI. This term has two significations in the law of evidence. First it means the obligation resting upon the party having the affirmative of the issue in a litigation to prove his case. In this sense, the burden of proof is generally upon the plain tiff. lf, however, the defendant sets up an af firmative defense, the burden is upon him. An example of such a defense is afforded when an insurance company, sued upon a marine insurance policy, sets up as its only defense the unsea worthiness of the insured ship. In such a case the defendant has the burden of proving that the ship was unseaworthy. Second, the term means the obligation to give evidence at some particular stage of the trial. For example, if the party having the affirmative of the issue has given evidence enough to entitle him to a judgment, the burden of giving further evidence rests upon his opponent. When the term is used in this
sense, it is proper to say that the burden of proof shifts from one party to the other during the trial. When used in the first sense, it is incorrect to say that the burden of proof shifts. The burden of making out his ease is always upon lam who has the affirmative of the issue. Hence, in a criminal case, it is always upon the Govern ment, which is also bound to make out its case. i.e. to establish the guilt of the prisoner beyond a reasonable doubt. In civil cases, the one having the affirmative of the issue makes out his case if lie convinces the jury that the preponderance of proof is on his side. Consult Thayer, Pre inary Treatise on Evidence at the Common Lair 1898). See EVIDENCE; PROOF.