This post does not seek discuss the case as such. What is interesting is the comment
in the BBC's article about proving innocence. It is not for the defendant in a criminal case to prove his innocence. I fear that there is some danger that we are losing sight of this essential point. In recent times, we have heard much of "rebalancing the system in favour of victims” (White Paper "Justice for All" - 2002 Cm. 5563) and denunciation of the old adage - " it is better that ten guilty persons go free than one innocent convicted" - a comment which appears in William Blackstone's "Commentaries on the Laws of England" published in the 1760s.
What is referred to by lawyers as "the burden of proof" is a burden resting on the prosecution. The "standard" of proof is, in the now time-honoured phrase, "beyond a reasonable doubt." If a reasonable doubt exists, the defendant is entitled to the benefit of it. The standard of proof is a high standard.
In modern law, "making the jury sure" is often used. Thus, the jury or magistrates must be "sure" of the defendant's guilt.
It was in the famous case of Woolmington v Director of Public Prosecutions  AC 462 (Viscount Sankey LC, Lord Hewart LCJ, Lord Atkin, Lord Tomlin and Lord Wright) - that the burden and standard of proof were set out by the House of Lords. Viscount Sankey, the Lord Chancellor, stated -
"Through-out 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 subject to what I have already said as to the defence of insanity and subject also to any statutory exception. 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."
In 1935, the defendant was referred to as "the prisoner." This term is now used only for those serving sentences of imprisonment. Interestingly, the case also states that the Attorney-General of the day gave his "fiat" (i.e. permission) for an appeal to the House of Lords. The requirement for this fiat lasted until the Administration of Justice Act 1960 and afterwards the question of whether an appeals would be allowed to the House of Lords was decided by the judiciary. This remains the situation now that the House of Lords has been replaced by the Supreme Court of the U.K.
In modern law, the burden and standard of proof remain as laid down in Woolmington's case. Viscount Sankey's speech referred to certain exceptions. One is the common law defence of insanity where the defendant bears the burden of proof. Where the defence have a burden of proof, the standard of proof is the lower standard of "on a balance of probabilities." A further exception is where a statute places a burden on the defence. This category has expanded massively by the enactment of what are often referred to as "reverse onus provisions." Since the Human Rights Act 1998, any such provision is open to challenge on the basis of its possible incompatibility with the presumption of innocence guaranteed by Article 6(2) of the European Convention on Human Rights. This is a complex topic. In "The Modern Law of Evidence" by Adrian Keane (8th ed) - (now in its 9th ed), the question of burden and standard of proof takes some 38 very detailed pages.
In Attorney-General's Reference (No. 4 of 2002)  1 AC 264, Lord Bingham said - "The underlying rationale of the presumption of innocence in both domestic law and in the Convention, is that it is repugnant to ordinary notions of fairness for a prosecutor to accuse an accused of a crime and for the accused then to be required to disprove the accusation on pain of conviction and punishment if he fails to do so."
Thus, it is not for defendants to prove their innocence: it is for prosecutors to prove their guilt. This "golden thread" remains a bedrock of our criminal procedure though it often seems necessary to dig down deeply to find it. In doing so one digs through matters such as "reverse burdens of proof"; statutory provisions affecting the "right to silence"; admissibility of "bad character"; "admissibility of hearsay"; "retrial for serious offences"; rules about "disclosure", before trial, of the prosecution and defence cases and then there is the growing impact of the "Criminal Procedure Rules." These are all areas where our law has undergone major changes in recent years and which, in one way or another, seem to blur the view of the "golden thread."
Criminal Law and Justice - 7th August 2010 - "Reasonable Doubt" - authors David Wolchover and Anthony Heaton-Armstrong
The serious student / legal professional should read "The presumption of innocence in Irish criminal law: Recent trends and possible explanations" by Dr Claire Hamilton and her book "The presumption of innocence in Irish law." Although written in the context of the law in the Republic of Ireland, the article and the book make extensive references to the law in England and Wales.
See also "Four threats to the presumption of innocence" by Professor Andrew Ashworth (Vinerian Professor of English Law, Oxford). Prof. Ashworth wrote about the negative effects of recent criminal justice policies on the presumption in England and Wales and identifies four sources, namely:
... confinement, by defining offences so as to reduce the effect of the presumption; erosion, by recognising more exceptions; evasion, by introducing civil law procedures in order to circumvent the rights conferred on accused persons; and side-stepping, by imposing restrictions on the liberty of unconvicted persons that fall only slightly short of depriving them of their liberty.
Any law student seeking a "First" would do well to master Prof. Ashworth's work.
The rights of defendants in criminal proceedings - European Union - the Bar Council played a significant part in producing this