As goes the famous ‘golden thread’ speech given by Viscount Sankey in Woolmington v DPP ; “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 simpler terms, the general rule above is that the prosecution carries a legal burden to prove the elements of the offence and that the accused only need to raise a defense on a burden that is merely evidential.
A legal burden is one where there is an obligation to prove, which is a heavy responsibility and would generally reside on the prosecution. A judge would direct a jury as to the burden of proof and failing so or giving an incorrect direction would result in a quashed conviction. An evidential burden on the other hand is a much lighter burden, where it requires the accused to merely raise the defense, rather than to prove it.
As well as the general rule created by Viscount Sankey, there were exceptions as well, where the legal burden has been shifted to the accused to prove his defense on a balance of probabilities.
The two exceptions given by Viscount Sankey are that the defense of insanity and statutory reversals. The defense of insanity will require the application of the McNaghten Rules if it is alleged by the accused, which will have to prove the rules in McNaghten with a legal burden on a balance of probabilities. If insanity is being purported by the prosecution, the case on point would be Robertson , where the accused was said to have punched his mother to the ground and stamped on her head and thigh whilst wearing heavy boots or shoes. Here, the burden on the prosecution is a legal one, to satisfy the jury beyond reasonable doubt.
Statutory reversals are where ‘reverse onuses’ are placed upon the accused by statute, either impliedly or expressly. This is where the crux of the issue is placed, regarding the principle given by Viscount Sankey and the presumption of innocence. Reverse onuses give the accused a much heavier burden, which is a legal burden to prove his defense whilst the presumption of innocence would have given the accused a much lower burden, an evidential burden. However, before a shift of burden can take place, there must be consideration given to Article 6(2) of the European Convention on Human Rights (ECHR) which provides for the presumption of innocence until proven guilty, in deciding the burden. There is then a difficulty for a court in upholding a reverse onus because under s.6 of the HRA 1998 it is unlawful for it to act in a way which is incompatible with a Convention right. If the courts are unable to decide in a way which is compatible with a Convention, s.4 of the HRA confers authority upon the courts to make declarations of incompatibility for statutory provisions they find to be incompatible with the ECHR.
An implied reversal is when an Act of Parliament lays down both the offence and...