On the Balance of Probabilities - But What Does That Mean?
On the Balance of Probabilities - But What Does That Mean?
In criminal law, we use two different standards of proof, the most well known is 'beyond reasonable doubt' (although these days expressed as 'so that you are sure'), and the balance of probabilities.
The latter standard of proof gets less attention but is nonetheless of critical importance in criminal cases. Whilst we hear the term bandied about in courts up and down the land on a daily basis, we hardly ever hear lawyers articulating its meaning to the court, which may well be a serious error of judgement if a magistrates' court is hearing the case.
In Miller v Minister of Pensions  2 All ER 372 (a civil case) Lord Denning expressed the legal test in this way [374A-B]:
'...the case must be decided according to the preponderance of probability. If at the end of the case the evidence turns the scale definitely one way or the other, the tribunal must decide accordingly, but if the evidence is so evenly balanced that the tribunal is unable to come to a determine conclusion one way or the other, then the man must be given the benefit of the doubt. This means that the case must be decided in favour of the man unless the evidence against him reaches the same degree of cogency as is required to discharge a burden in a civil case. That degree is well settled. It must carry a reasonable degree of probability, but not so high as is required in a criminal case. If the evidence is such that the tribunal can say: “We think it more probable than not,” the burden is discharged, but, if the probabilities are equal, it is not.'
In Pope v General Dental Council  EWHC 278 (Admin) the following assistance can be derived:
'In a civil case, the burden of proof is fixed at the beginning of the trial by the state of the pleadings and remains there never shifting. Similarly, in criminal cases, the burden of proof lies on the same party (in practice usually, but not always, the prosecution) throughout.
The general practical impact of this is that at no stage of the proceedings is the fact finder entitled to say that the evidence on any given issue has accreted to the extent that the persuasive burden of proof has, as a result, been effectively shifted from one party onto the other party.
This point was authoritatively and emphatically made by Viscount Sankey L.C. in Woolmington  AC 462 at page 481:
'If at any period of a trial it was permissible for the judge to rule that the prosecution had established its case and that the onus was shifted on the prisoner to prove that he was not guilty and that unless he discharged that onus the prosecution was entitled to succeed, it would be enabling the judge in such a case to say that the jury must in law find the prisoner guilty and so make the judge decide the case and not the jury, which is not the common law. It would be an entirely different case from those exceptional instances of special verdicts where a judge asks the jury to find certain facts and directs them that on such facts the prosecution is entitled to succeed. Indeed, a consideration of such special verdicts shows that it is not till the end of the evidence that a verdict can properly be found and that at the end of the evidence it is not for the prisoner to establish his innocence, but for the prosecution to establish his guilt. Just as there is evidence on behalf of the prosecution so there may be evidence on behalf of the prisoner which may cause a doubt as to his guilt. In either case, he is entitled to the benefit of the doubt. But while the prosecution must prove the guilt of the prisoner, there is no such burden laid on the prisoner to prove his innocence and it is sufficient for him to raise a doubt as to his guilt; he is not bound to satisfy the jury of his innocence.'
The importance of applying the burden of proof on any issue by taking into account all of the evidence at the end of the case was also stressed by Viscount Sankey in Woolmington at page 483 deploying a metaphor the vividness of which has been long since been rewarded with the status of cliché:
"Throughout the web of the English Criminal Law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner's guilt … If, at the end of and on the whole of the case, there is a reasonable doubt, created by the evidence given by either the prosecution or the prisoner, as to whether the prisoner killed the deceased with a malicious intention, the prosecution has not made out the case and the prisoner is entitled to an acquittal. No matter what the charge or where the trial, the principle that the prosecution must prove the guilt of the prisoner is part of the common law of England and no attempt to whittle it down can be entertained."
And, with respect specifically to the facts of that case in which the charge was one of murder:
"If the jury are either satisfied with his explanation or, upon a review of all the evidence, are left in reasonable doubt whether, even if his explanation be not accepted, the act was unintentional or provoked, the prisoner is entitled to be acquitted."
The time at which the burden of proof must be applied is, therefore, at the end of the case without either attenuation or reversal as a result of the ebb and tide of evidential fortunes in the hearing which had preceded it.
The evidence in favour of one party is put in one pan of the scales and that of the other in the other pan. As the case progresses, one pan may rise as the other falls and vice versa. When the evidence has concluded, the scales will have tipped in one direction or another or will have ended up evenly balanced. The fact that one party bears the burden of proof means that he will lose not only if the pan has fallen in favour of the other party but also if the scales end up evenly balanced.
The application of the burden of proof does not, however, involve putting some unspecified weight into the pan of the party who does not bear the burden of proof before any evidence is called. The burden of proof and the standard of proof comprise the criteria which are to be applied to all of the evidence after it is complete in order to determine how any given issue is to be resolved. As such, the burden of proof has no "weight" either in the scale analogy or, literally, in the context of a contested issue as a piece of evidence in itself. To say that the burden remains on one party throughout is merely to make the point that, however imbalanced the scales may appear to be at any given stage in the proceedings, the test to be applied remains unchanged throughout.'
So, Not So Simple After All?
As you can see, the issue of burdens and standards of proof has exercised the courts on a great many occasions in the past (there are at least another dozen or so important judgments dealing with these issues). We understand that these issues lie at the heart of almost all criminal cases and leave nothing to chance. It is essential that all tribunals deciding cases correctly understand the underlying framework of criminal evidence.
How we can assist
If you need specialist advice, then get in touch with the team on 0208 808 0774 or alternatively by email at firstname.lastname@example.org and let us help, we deal with all manner criminal offences on a daily basis and have the expertise to get you the best result possible.