- In criminal cases there are two main burdens. The first is the legal burden on the prosecution to prove the offence against the defendant beyond reasonable doubt. The second is the evidential burden on the defendant to introduce sufficient evidence to prove the probability of the defence or to create a reasonable doubt in the case of the prosecution. Esangbedo v The State, Nnaemeka-Agu JSC explained the meaning of the burden of proof in criminal cases, “For the avoidance of doubt the expression ‘burden of proof’ is often loosely used to include the burden to prove the guilt of a defendant beyond reasonable doubt – a burden which is always in the prosecution and never shifts – and the burden of introducing evidence on an issue in the trial – which may be place by law on either the prosecution or the defence”
- The nature of the evidential burden on defendants in criminal cases is far from settled. In Popoola v The State, the Supreme Court considered the defence of insanity. Ariwoola JSC said, “The standard of such proof is not as high as that cast on the prosecution. It is not proof beyond reasonable doubt but it is proof of reasonable probability, proof sufficient to create a reasonable doubt in the mind of a fair minded jury as to the sanity of the accused.” Then Ngwuta JSC said, “…..the burden of proof on the accused who relies on a defence of insanity is less than the burden cast on the Prosecution to prove his guilt beyond reasonable doubt. The burden of proof is satisfied on a balance of probability or preponderance of evidence.” The question is whether the views of the learned justices in Popoola (supra) are conflicting and if so, which is the correct view. Is the burden discharged on the balance of probabilities or upon proof of reasonable probability sufficient to create a reasonable doubt in the mind of the Judge?
- The burden of proof on defendants in criminal cases requires clarification because there are two kinds of burden on the defendant. The first is the statutory burden of proving the facts required to establish any defence to the charge. Section 139(1) of the Evidence Act 2011 states that, “Where a person is accused of any offence the burden of proving the existence of circumstances bringing the case within any exception or exemption from, or qualification to, the operation of the law creating the offence which he is charged is upon such person.” The second is the evidential burden of introducing sufficient evidence of facts which create reasonable doubt in the case of the prosecution. Section 135(3) of the Evidence Act states that, “If the prosecution proves the commission of a crime beyond reasonable doubt, the burden of proving reasonable doubt is shifted on to the defendant.”
- In Partap v State of Uttar Pradesh, the Supreme Court of India considered the burden of proof on the defendant and held that there is in fact more than one kind of burden on defendants in criminal cases. The first is the statutory burden of proving the existence of circumstances bringing the case within any defence to the offence and the second is the burden of introducing evidence sufficient to create reasonable doubt about the guilt of the defendant. Therefore, if the evidence does not prove the existence of any defence but upon a consideration of the whole evidence reasonable doubt is established then the defendant will be entitled to an acquittal. The Supreme Court, citing the decision in Rishi Kesh Singh, said, “The legal position of a state of reasonable doubt may be viewed and stated from two opposite angles. One may recognize, in a realistic fashion, that although the law prescribes only a higher burden of the prosecution to prove its case beyond reasonable doubt and the defendant lower burden of proving his plea by a preponderance of probability only, yet there is in practice, a still lower burden of creating reasonable doubt about the defendant guilt and that a defendant can obtain an acquittal by satisfying this lower burden too in practice. The objection to stating the law in this fashion is that it looks like introducing a new type of burden of proof, although it may be said, in defence of such statement of the law that it only recognizes what is true.”
- There is a burden on the defendant where; (i) where the law imposes upon him the burden of proving particular facts. See the proviso to section 36(5) of the Constitution FRN; or (ii) where the law requires him to prove the existence of any exception or exemption or qualification to the law creating the offence. See section 139 of the Evidence Act; or (iii) where any fact is especially within his knowledge. See section 140 of the Evidence Act. Section 136(1) of the Evidence Act places the burden of proof for any particular fact on the person who asserts the existence of that fact. See also section 139(1) of the Evidence Act. In NAF v Kamaldeen, a General Court Martial convicted the respondent of stealing money belonging to the Nigerian Air Force. In his defence the respondent stated that the Chief of Air Staff authorised the withdrawal of the money. The Supreme Court held that the burden was on the respondent to prove the alleged authorisation. Musdapher JSC said, “It is settled law that where a person is accused of any offence, the burden of proving the existence of circumstances bringing the case within any exception or exemption to the law lay within the accused. …… In the instant case, huge amounts of money were taken out from the Nigerian Air force and the money was shared amongst the officers who caused and participated in the withdrawal. If they had the authority to do so, the burden is clearly on them to prove the same, more so when the purpose of withdrawing the money was defeated.”
- Section 137 of the Evidence Act 2011 states that, “Where in any criminal proceedings the burden of proving the existence of any fact or matter has been placed upon a defendant by virtue of the provisions of any law, the burden shall be discharged on the balance of probabilities.” One must admit that several judicial authorities hold that the burden on the defendant must be discharged on the balance of probabilities. However, this author disagrees with the provisions of section 137 of the Evidence Act and humbly submits that the defendant does not discharge the evidential burden on the balance of probabilities.
- The standard of proof on the defendant can be found in section 121(a) of the Evidence Act. That section states that, “A fact is said to be proved when, after considering the matters before it, the court either believes it to exist or considers its existence so probable that a prudent man ought, in the circumstances of the particular case, to act upon the supposition that it does exist.” Therefore the burden is discharged if the defendant can satisfy the trial Judge of the reasonable probable existence of the facts. In Oteki v The State, Oputa JSC said, “Where the facts deposed to by a witness look probable when considered in relation to all the surrounding circumstances of the case, they induce belief. Probability is always a safe guide to the sanctuary where truth resides.”
- A defendant does not discharge the evidential burden on the balance of probabilities or on the preponderance of evidence because in criminal cases, unlike in civil cases, there is no imaginary scale and no weight of evidence. In Ozaki v The State, Obaseki JSC said, “It was therefore not a statement of law by the Supreme Court that the defendant’s duty in relation to the defence of alibi is to establish the defence on the balance of probabilities. Balance of probabilities means preponderance of evidence. In other words, the defendant person adduces evidence which outweighs the evidence of the prosecution on the issue of alibi. That is not the law. As stated above, the only onus on the defendant is the evidential burden. The effect of such evidence is not dependent upon its preponderance. It may be scanty or minimal but yet very effective in raising reasonable doubt in the minds of the tribunal.”
- In Olonade v Sowemimo, Muhammad JSC explained the meaning of the standard of proof in civil cases, the balance of probabilities, “My Lords, in a civil matter such as this, the court decides the case on the balance of probabilities or preponderance of evidence. The trial court does this by first deciding which evidence it accepts from each of the parties, putting the accepted evidence adduced by the plaintiff on one side of the imaginary scale and that of the defendant on the other side of the scale and weighing them together. The court then decides which side’s evidence is heavier, not by the number of witnesses called by either party or on the basis of the one being oral and the other being documentary, but by the quality or probative value of the evidence be it oral and/or documentary.” This is certainly not the manner in which criminal trials are conducted. In many criminal trials the defendant does not give evidence. There is no imaginary scale to weigh the evidence of both sides and if at the end of the case for the prosecution a prima facie case is not proved, the defendant must be discharged.
- It is for this reason that there is nothing wrong with the trial court in criminal cases evaluating the evidence of the prosecution first and making findings before evaluating the evidence of the defence. Unlike in civil cases the evidence of the prosecution and the defence are not placed side by side on an imaginary scale and decided on the preponderance of evidence. In Oteki v The State, the trial judge considered the evidence of the prosecution first and found that the charge had been proved before considering and rejecting the evidence of the defendant. The appellant complained that this procedure caused to the trial judge to wrongly evaluate the evidence. The Supreme Court held that there was nothing wrong with the trial judge assessing the prosecution’s case first and making findings of fact before considering and evaluating the appellant’s defence.
- One must admit that several judicial authorities hold that the burden on the defendant must be discharged on the balance of probabilities. However, there is also judicial authority that the standard of proof on the defendant seeking to prove the defences of alibi or insanity is not on the balance of probabilities but an evidential burden to establish the reasonable probable existence of the facts. That burden was explained in Ukwunnenyi v The State, where Oputa JSC said, “There is however an onus on the defendant – the onus of introducing evidence tending to show that he might not have been (not that he was not) at the scene and at the time the alleged offence was committed. If any trial court insists that the evidence tendered by the defendant (pleading the alibi) must show that he was not there, that will be casting the onus of proving his innocence on a defendant. That will be wrong. If the evidence tendered by the defendant merely raises a doubt as to whether he was present at the time and place of the offence that is enough to secure him an acquittal.”
- From the foregoing, can we say that the burden of proof on defendants in criminal cases is discharged on the balance of probabilities or upon proof sufficient to create a reasonable doubt in the mind of the Judge? Section 137 of the Evidence Act which states that, the standard of proof to discharge the burden on the defendant in criminal cases is on the balance of probabilities represents the current position of the law on this matter. However, it is the humble opinion of this author, supported by judicial authority that the burden of proof on the defendant is discharged on the reasonable probability of the existence of the fact to be proved and is established where there is sufficient evidence to show reasonable doubt in the case of the prosecution.
 (1989) NWLR (pt. 113) 57 at 69.
 (2013) 7 MJSC (pt.2) 191
 (1976) AIR (vol.63) 966 at 973, Rishi Kesh Singh (1970) AIR 51 at 89.
 (2007) NWLR (pt.1032) 164 at 188. See also, Abadom v The State (1997) NWLR (pt.479) 1 at 19,
Ohuka v The State (1988) NWLR (pt.86) 36, Ariche v The State (1993) NWLR (pt.302) 752 at 769,
Ohunyon v The State (1996) NWLR (pt.436) 264
 (1986) ANLR 371 at 392. See also, Ali v The State (1988) ANLR 1 at 28, Onuoha v The
State (1989) NWLR (pt.101) 23 at 32.
 (1990) ANLR 94 at 107. See also, Ukwunnenyi v The State (1989) NWLR (pt.114) 131 at 155.
 (2014) LPELR-22914(SC) at 27,
 (1986) ANLR 371 at 378, See also, Kim v The State (1992) NWLR (pt.233) 17 at 44, Igago v The State (1999) NWLR (pt.637) 1, Ezeuko v The State (2016) LPELR 40046 (SC)
 (1989) NWLR (pt.114) 131 at 155. See also, Esangbedo v The State (1989) NWLR (pt.113) 57 at 70, Adio v The State (1986) NWLR (pt.24) 581, Peter v The State (1997) NWLR (pt.496) 625 at 642, Onafowokan v The State (1987) NWLR (pt.61) 538, Abudu v The State (1985) NWLR (pt.1) 55, Aliyu v The State (2013) 6/7 MJSC (pt.3) 64, Olaiya v The State (2010) 1 MJSC (pt.1) 73, Esene v The State (2017) LPELR-41912(SC),