Where the text of a statute did not make clear where the burden of proof lay, the court should consider the mischief at which the statute was directed and the ease or difficulty that the different parties would face in discharging the burden of proof.

B (19 years), and C (16 years), were cornered by police on the roof of a warehouse. B was held by police on the roof. C produced a pistol and shot one of the police officers. It was alleged that B had shouted ‘Let him have it, Chris’ before the fatal shot was fired. Both were convicted of murder and B was sentenced to death and executed in 1953 despite widespread pleas for clemency. In 1993 he was posthumously pardoned.

A clear and unambiguous direction on the burden of proof was a cardinal requirement of a properly conducted trial. The direction in this case was not satisfactory. By stressing the abundant evidence calling for an answer in support of the prosecution case and by suggesting that that case had been ‘established’ and that there was a burden on C to satisfy the jury that the killing had been accidental (however little, on the facts of the case, the injustice caused to C thereby) the jury could well have been left with the impression that the case against B was proved and that they should convict him unless he had satisfied them of his innocence.

C was convicted of health and safety breaches following a dumper truck accident in which an employee died. Their appeal was dismissed in the Court of Appeal, and they appealed to the House of Lords.

The prosecution had to prove that C had not ensured the employee’s health and safety or prevented exposure to risk. This established breach unless the defendant could establish that it had not been reasonably practicable to do so. The prosecution did not have to identify and prove specific breaches of duty; the overriding test was whether or not defendants had been given fair notice of the claim against them.

E was convicted of selling alcohol without a licence. He appealed on the grounds that the prosecution had not produced evidence that he had not been granted a licence. His appeal was dismissed.

Under the common law where a statute prohibited an act, save in specified circumstances, the court could construe the statute such that the burden of proving the existence of the circumstances, including the granting of a licence, could lie on the defendant.

H was convicted of being in unlawful possession of a Class A drug, morphine. One issue at the trial was the composition of the alleged drug. The statute provided that if the proportion of morphine was not more than 0.2 per cent the substance was not unlawful under the regulations. The prosecution had not adduced evidence on the proportion of morphine, the judge would not allow a defence submission of no case to answer.

The House acknowledged the principle that the burden of proof on an element of the defence could be placed on the defendant. However, in this instance the legal burden of proving the composition of the substance was on the prosecution. Courts should examine the linguistic construction of the statute and if that is ambiguous take into account policy considerations and also the relative ease with which defence or prosecution could discharge the burden. The same approach should be taken whether the offence was a summary one or a trial on indictment. Edwards was approved. Hunt and Edwards have been largely overtaken by the post-HRA cases such as Lambert.

J was convicted of violations of the Trade Marks Act 1994. He had relied on s92(5),whereby it was a defence for the accused to show he believed on reasonable grounds that the use of the sign in question did not infringe the statute. The Court of Appeal, upholding the conviction, had not made it clear where the burden of proof on this section lay. The House of Lords refused the appeal and pronounced on the burden of proof.

Article 6(2) ECHR permitted reverse burdens provided they were kept within reasonable limits which took account of the importance of what was at stake and maintained the rights of the defence. In this instance there were compelling policy reasons to place the legal burden of the specific defence on the accused to the standard of the balance of probabilities.

A conjoined appeal. Two Albanian nationals, MK and PG, had been convicted respectively of conspiring to supply a Class A drug and possession of identity documents with improper intention and of possession of identity documents with improper intention. At trial they claimed in their defence that they had been victims of trafficking and slavery under s45(1) Modern Slavery Act 2015. This set out several provisions needed to mount the defence of victimization due to slavery or trafficking. The trial judges ruled that the defendants had the evidential burden of providing they had been trafficked and the prosecution the legal burden of disproving this but that the legal burden of proving the other elements of the defences under s45 lay on them,

The Court of Appeal held that s45 did not implicitly require defendants to bear the legal burden of proof on any elements. To rule otherwise would thwart the will of Parliament that the victims of trafficking or slavery should be convicted of offences committed as a result of their victimization. The prosecution was likely to have less difficulty proving to the criminal standard that the defendants had a realistic alternative to committing the offences than the defendants establishing on the balance of probabilities that they had no realistic alternative than to do what they did. MG’s conviction was quashed but PG’s was upheld since the evidence of guilt was overwhelming.

A civil servant was charged under the Official Secrets Act 1989, having handed to an MP’s researcher a copy of a letter from the PM to the US President. The Act required the defendant to prove that he did not know and had no reasonable cause to believe the disclosure of the secret information would be damaging. The judge concluded that the Act infringed the presumption of innocence, but this was justified in the circumstances. The Appeal Court allowed the defendant’s appeal.

The Act could operate effectively without obliging the defendant to prove that he did not have a guilty state of mind. Given its natural meaning, the Act was incompatible with Art 6 ECHR, and the relevant sections should be ‘read down’ by applying a similar interpretation to that achieved by s118 Terrorism Act 2000. That provides: ‘If the person adduces evidence which is sufficient to raise an issue with respect to the matter the court or jury shall assume that the defence is satisfied unless the prosecution proves beyond reasonable doubt that it is not.’

L was convicted of being in possession of a controlled drug. The judge directed the jury that the prosecution had to prove that L knew he had the bag in his possession and that the bag contained the controlled drug. If L wanted to rely on the defence in s28(3)(b)(i) that he did not believe or suspect or have reason to suspect that he was in possession of a controlled drug he had to prove on the balance of probabilities that he did not know the bag contained a controlled drug. His conviction was upheld by the Court of Appeal and the House of Lords. L could not rely on the HRA since it was not in force at the time of trial. The House held by a majority that when the HRA was in force, s28 of the 1971 Act should be read as imposing an evidential burden on the defendant.

In order to comply with s3(1) HRA it may be necessary to read down a statutory provision which imposes a legal burden of proof on the defendant. Given the seriousness of the offence, if the HRA had been in force, the court should have imposed only an evidential burden on the accused in relation to s28(3)(b)(i). However, Lord Steyn stated (at para 43) that even if that direction had been given in this instance ‘the appellant’s conviction would have been a foregone conclusion’.

On a charge of wounding with intent to cause grievous bodily harm, the accused argued that he was acting in self-defence. The trial judge held that the burden of proving this lay on him. The Court of Appeal allowed the appeal.

The prosecution had the legal burden of disproving self-defence. The issue should only be put to the jury if the accused produced sufficient evidence to make it possible for a reasonable jury to acquit. This is an instance of what are known as common law defences where the accused has the task of producing sufficient evidence to make the issue a live one before the jury, but the legal burden remains on the prosecution.

The House of Lords considered two conjoined appeals. Sheldrake concerned s5(1)(b) Road Traffic Act 2000 and A-G Ref concerned s5(2) Terrorism Act 2000.Both provisions imposed reverse burdens on the accused. The House held that the task of the court was not that of deciding whether a reverse burden should be imposed on the defendant but whether a burden that Parliament had enacted unjustifiably infringed Art 6(2). The Road Traffic Act provision imposing the burden was justifiable, but the Terrorism Act provision was not.

The House acknowledged that the decision in relation to the Terrorism Act meant flouting the clear will of Parliament in relation to the allocation of the burden of proof.

W was convicted of the murder of his wife by shooting. He claimed the gun had been fired accidentally. The trial judge and the Court of Appeal had held that the defence of proving lack of mens rea was on W. The House of Lords allowed the appeal.

At common law in criminal proceedings the entire burden of proving, beyond reasonable doubt, the actus reus and the mens rea is on the prosecution. This included disproving any defences. The two exceptions to this rule were the defence of insanity and statutory provisions.