B (A Minor) v Director of Public Prosecutions

A statutory offence is presumed to require mens rea unless Parliament excludes it expressly or by necessary implication. A necessary implication must be compellingly clear, particularly where the offence is serious, carries substantial stigma and covers a broad range of conduct.

A mistake of fact which prevents the required mens rea need only be honest. Its reasonableness is evidence bearing on whether the belief was genuinely held, but it is not an independent condition of the defence. For an offence under section 1(1) of the Indecency with Children Act 1960, the prosecution must therefore prove the absence of a genuine belief that the child was aged 14 or over. No special rule of strict liability applies merely because an offence is age-related or protects children from sexual conduct.

The appellant, aged 15, repeatedly asked a 13-year-old girl to perform an act of oral sex. He was charged with inciting a child under 14 to commit an act of gross indecency contrary to section 1(1) of the Indecency with Children Act 1960. It was admitted that he honestly believed the girl was over 14, but no finding was made about whether that belief was reasonable.

Harrow Youth Court ruled that his state of mind afforded no defence because the offence imposed strict liability as to age. He then pleaded guilty and received an 18-month supervision order. On an appeal by case stated, the Divisional Court dismissed his appeal in R v B (A Minor) v Director of Public Prosecutions [1999] 3 WLR 116.

The House considered whether mens rea was required in relation to the child's age, whether an honest mistake had to be reasonable, and where the burden of proof lay.

1. Disposition. The House unanimously allowed the appeal and quashed the conviction. Lord Nicholls of Birkenhead delivered a leading speech which Lord Irvine of Lairg LC adopted. Lord Mackay of Clashfern agreed with the reasons given by Lord Nicholls, Lord Steyn and Lord Hutton.

2. Presumption of mens rea. Per Lord Nicholls, Lord Steyn and Lord Hutton, a statutory offence is presumed to require a mental element unless Parliament excludes it expressly or by necessary implication. The implication must be compellingly clear. Relevant considerations include the statutory language, the nature and seriousness of the offence, the mischief addressed and the wider statutory context. The governing approach in Sweet v Parsley [1970] AC 132 was applied.

3. Construction of section 1(1). The Indecency with Children Act 1960 did not expressly exclude mens rea concerning age. The offence was serious, carried grave stigma and applied to conduct extending from predatory abuse to sexual approaches between teenagers. These features strengthened the presumption. Its protective purpose did not itself establish that Parliament had selected strict liability as the means of protecting children.

4. Per Lord Nicholls and Lord Steyn, the disparate offences collected in the Sexual Offences Act 1956 disclosed no coherent legislative policy capable of supplying the necessary implication. Express mistake provisions elsewhere in that Act did not establish that silence in section 1(1) of the 1960 Act imposed strict liability. Sections 14 and 15 were also materially narrower because an assault was an ingredient of those offences.

5. Honest mistake. The required mental element was the absence of a genuine belief that the child was aged 14 or over. A belief need not rest on reasonable grounds. Reasonableness remains relevant evidence when deciding whether the belief was genuinely held, but an unreasonable belief which negatives mens rea does not become criminal negligence. The reference to reasonable grounds in Lord Diplock's formulation in Sweet v Parsley was therefore to be omitted for the future.

6. Burden of proof. Once evidence raised the possibility of an honest belief that the child was 14 or over, the prosecution had to prove its absence in the ordinary way. There was no basis for placing the legal burden on the defendant.

7. Earlier age-related authorities. The correctness of the actual decisions in Regina v Prince and R v Maughan did not require determination because they concerned different offences and provisions. However, no special rule of construction for age-based sexual offences could be extracted from Prince. Its reasoning based on conduct being wrong in itself or on defective drafting was unsound and had to be read in light of the modern presumption of mens rea.

1. House of Lords: Unanimously allowed the appeal and quashed the appellant's conviction: B (A Minor) v Director of Public Prosecutions [2000] 2 AC 428.
2. Divisional Court: Brooke LJ, Tucker J and Rougier J affirmed the justices' ruling that the offence imposed strict liability as to age and dismissed the appeal by case stated: R v B (A Minor) v Director of Public Prosecutions [1999] 3 WLR 116.
3. Harrow Youth Court: Ruled that the appellant's honest belief concerning the girl's age afforded no defence. The appellant then pleaded guilty and received an 18-month supervision order.