Burden and Standard of Proof

In each case, one side has the burden of proof. Having the burden means a party must prove its case to the trier of fact-judge or jury, whoever is weighing the evidence. The burden of proof can shift from one side to the other during hearing or a trial depending on the kind of case. For example, in criminal, the prosecution has the burden of proving the defendant committed a crime. In many states, the defendant has the burden of proving certain defences to that crime. But, particularly in criminal cases, opposing sides can be held to different standards of proof.

The standard of proof refers to the extent to which a party with the burden of proof has to prove its case. In general, the higher the stakes, the higher the standard of proof. A higher standard of proof means that, to find for the side with the burden of proof, the trier of the fact has to be more certain that that side has proved its case.

Meaning and nature of Burden of proof

Burden of proof is the obligation which the law imposes on a party who desires the court to give judgment in his favour or who will fail if no evidence is adduced whether in criminal or civil trial.  In Elemo v Omolade (1968) NMLR 359 the court observed that in discussing the burden of proof there are two limbs that cannot be dispensed with, they include the following:

            i.            The burden of proof as a matter of law and pleading i.e the burden as it has been called of establishing a case whether by preponderance of evidence or beyond reasonable doubt.

         ii.            The burden of proof in the sense of introducing evidence.

The first limb of  burden of proof as canvassed by the court in the above case is referred to as legal burden of proof. This burden is fixed by law on a party and never shifts. It is a burden on a party to prove his case to the satisfaction of the court, whether by preponderance of evidence or beyond reasonable doubt. Legal burden of proof is settled throughout the trial by the state of pleading and is settled by law, it is allocated by rules of law and are fixed at the beginning of the case.

The second limb of burden of proof is not always stable as it shifts constantly more as one scale of evidence or the other preponderate. In this sense, the onus propend rest on the parties who will fail if no evidence at all or no more evidence as the case may be were given on either side. It rests before evidence is gone upon the party asserting the affirmative of the issue and itrest after evidence is gone into upon the party against whom a tribunal at the time the question arises will give judgment if no further evidence were adduced. The burden of intoducing evidence is the obligation on a party to adduce evidence on a particular fact.

We will now specifically examine burden of proof in civil and criminal cases.

a.    Burden of proof in Civil cases: The general burden of proof is on the party who alleges the existence of a fact in issue. Thus, the burden of proof is usually fixed by the state of pleading and where there is any dispute about the general burden of proof as the matter is resolved by the court as a matter of law. Where a defendant denies the allegations in the pleadings of the plaintiff, the general burden of proof is on the plintiff to establish the allegation in the pleadings. Once the plaintiff has done this, the onus of establishin the contrary facts shifts to the defendant. Note that a plaintiff’s claim may even fail where the defendant does not defend the action if the legal burden is not discharged. This point was analysed by the court in the case of  Pickford v Imperial Chemical Industries Plc (1998) 3 All ER 462, where the English House of lords held that where the trial judge does not believe the evidence of either party on an issue in dispute, the party who has the legal burden of proof is the party who must fail. The court further pronounced on this matter of law in the case of Oguejiofor v Siemens Ltd (2008) 2 NWLR pt 1071, 283 the court in this case held that in civil cases, the burden of proof is on the plaintiff to proof his case and the burden is not removed simply because the defendant abandons his case by refusing to any evidence in support of his defence or fails to cross-examine plaintiff’s witnesses. It was held that the defendant bears no burden to adduce any evidence or satisfactory evidence. It was also held that where the plaintiff has produced evidence in support of his prima facie will entitle him to judgment, the defendant will need to lead some evidence to enable the court to consider on whose side the case preponderances. 

b.     Burden of proof in Criminal cases: The burden of proof in criminal cases is provided for respectively by the provisions of the Nigerian 1999 Constitution (as amended) and the Evidence Act 2011. The presumption of innocence held in favour of the defendant in criminal cases fixes the burden on the prosecution to prove the existence of all elements of an offence or offences a defendant in criminal cases is charged with or the case fails. This position was canvassed by the court in the case of Kinnami v Bornu Native Authority (1957) NRMLR where the court held that it is not the duty of the accused to prove his innocence but it is the duty of the accuser to prove his guilt. By virtue of this, th burden is always on the prosecution to prove all the ingredients of the offence. The import of this presumption held in favour of the accused is that he is not deemed to have committed the offence until the prosecution is able to prove that the accused person actually committed the offence.

The second provision is section 135(2) of the Evidence Act, 2011 which provides that the burden of proving that any person has been guilty of a crime or a wrongful act, is subject to section 139 of the Act, on the person who asserts it. In the case of Woolmington v DPP, the accused had been convicted of the murder of his wife by shooting her in the kitchen of her mother’s house. The accused testified at the trial that the shooting was an accident. His story was that his wife had left him and returned to live with her mother; he had gone to the house to persuade her to come back to him, with the plan of producing a gun and threatening to shoot himself if she refused. On her refusal he duly poduced the gun, but some how it went off accidentally and shot her. In his direction to the jury, the tial judge stated that once the prosecution had proved that the deceased had died at the hands of the accused, then he was presumed to be the murderer unless the accused could satisfy the jury that it was an accident. However, the House of Lords held that the direction was wrong and allowed the appeal of the accused to it. The court held that the prosecution not only has the burden of proving that the accused killed the deceased, but that the killing was not an accident, that the accused as done it with malice required for the offence of murder.

Meaning and nature of standard of proof

While burden of proof is the obligation which the law imposes on a party who desires the court to give judgment in his favour or who will fail if no evidence is adduced whether in criminal or civil trial, standard of proof refers to the degree of probability facts must be proved to be true. The term standard of proof also means the “quantum of proof” required to discharge burden of proof. Although the law sets a degree of proof required to discharge a burden, no party is ever required  to prove facts to an absolute standard mathematical or certainty. It it noteworthy that standard of proof is categorised into standard of proof in civil cases and criminal cases. Thus, the standard of proof in criminal cases is higher in degree to civil cases. We will now consider these two categories below:

a.     Standard of proof in civil cases: Generally, in civil cases, the standard of proof is based on proof by preponderance of evidence. The plaintiff is not  required to proof his case beyond reasonable doubt, the burden on him is just to establish that the story is more likely to be true than that of the defendant. Standard of proof received judicial pronouncement in the case of Miller v Minister of Pensions (1947) AC 154 at 156, the court per Lord Denning stated thus:

the… degree of cogency… required to discharge a burden  in a civil case… is well settled. It must carry a reasonable degree of probability, but not so high as required in a criminal case. If the evidence is such that the tribunal can say: ‘we think it is more probable than not ‘the burden is discharged, but, if the probabilities are equal, it is not.

Standard of proof in criminal cases: Section 133(1) of the Evidence Act 2011 provides that there must be proof beyond reasonable doubt in criminal cases. This means that every ingredient of the offence must be provided. This point was illustrated in the case of Ishola v State (1962) 1 NMLR 259. The court cannot convict where there is a doubt about the accused’s guilt. Thus, the inquirer is not concerned with the proof of innocence of the accused, but the prove of guilt.