## Facts

- Stephanie Sweet, the appellant, was the sub-tenant of a farmhouse and rented out several rooms to others while retaining one for herself.
- Sweet occasionally visited the property to collect rent and mail but did not reside there full-time.
- Police searched the property during Sweet’s absence and discovered cannabis.
- Sweet was charged under Section 5(b) of the Dangerous Drugs Act 1965 with being concerned in the management of premises used for smoking cannabis resin.
- Sweet maintained she had no knowledge of drug use on her premises.
- The case turned on whether her lack of knowledge could exempt her from liability under the statute.

## Issues

1. Should Section 5(b) of the Dangerous Drugs Act 1965 be interpreted as requiring proof of mens rea, specifically knowledge of the illicit activity, or as imposing strict liability regardless of knowledge?
2. Does silence in a statutory provision regarding mens rea create an offence of strict liability?
3. How should courts determine whether to imply a mental element when a statute does not expressly address it?

## Decision

- The House of Lords held that the presumption of mens rea applies to statutory offences unless Parliament clearly indicates a contrary intention.
- The offence under Section 5(b) was deemed "truly criminal" and thus required proof that Sweet had knowledge of the drug use.
- Sweet’s conviction was quashed due to absence of evidence of her knowledge regarding the use of her premises for drug consumption.
- The court distinguished between "truly criminal" offences and regulatory offences, finding that more serious offences warrant a requirement for mens rea.
- The House of Lords criticized earlier approaches, particularly as seen in R v Prince, that had favored strict liability for statutory offences.

## Legal Principles

- There is a strong presumption at common law that mens rea is required for serious (truly criminal) offences unless explicitly excluded by legislation.
- Statutes silent on mens rea will not automatically be interpreted as creating strict liability unless the offence is regulatory or Parliament’s intent is clear.
- Regulatory offences related to public safety may appropriately be strict liability, but serious crimes require proof of a guilty mind.
- The decision in Sweet v Parsley reaffirmed the importance of protecting individuals from unjust criminal convictions due to strict liability.
- Subsequent guidance, such as the Gammon principles, clarified the criteria for identifying strict liability offences in statutory interpretation.

## Conclusion

The House of Lords in Sweet v Parsley established that, for statutory offences classified as true crimes, courts must presume a requirement for mens rea unless Parliament's intention to impose strict liability is clearly expressed, thus safeguarding against unjust criminal liability based solely on statutory silence.


Sweet v Parsley [1970] AC 132