Sierny v Director of Public Prosecutions

Under section 31 of the Anti-Social Behaviour Act 2003, an authorisation for dispersal powers must specify the grounds on which it is given within the authorisation itself. A statement that the authorising officer has reasonable grounds for the statutory belief is insufficient. The authorisation need not recite the underlying evidence or identify complainants. A brief, relevant and concise summary of the nature of the material supporting the belief is enough. The requirement is mandatory because the written authorisation must demonstrate a properly considered basis for the power and inform constables and later courts of the mischief addressed.

The claimant was convicted at Sheffield Magistrates' Court of knowingly contravening a dispersal direction given under section 30(4) of the Anti-Social Behaviour Act 2003. The direction was made under an authorisation issued by a police superintendent covering an area of Sheffield. The authorisation stated the statutory beliefs but gave no explanation of the grounds supporting them.

On appeal by way of case stated, the issue was whether section 31(1)(c)(ii) required the grounds to appear in the instrument of authorisation and, if so, whether the authorisation was invalid for failing to do so.

1. Appeal allowed and conviction quashed. The authorisation was invalid because it merely recited the superintendent’s statutory beliefs and did not specify the grounds for those beliefs.
2. Section 31(1)(c)(ii) uses mandatory language. The authorising officer must specify the grounds in the authorisation itself. The requirement is not satisfied by stating that the officer has reasonable grounds for believing that members of the public have been intimidated, harassed, alarmed or distressed, or that anti-social behaviour is a significant and persistent problem.
3. The statute does not require detailed evidence, the names of complainants, or a full rehearsal of the material considered. A brief, relevant and concise summary of the nature of that material is sufficient. This provides information to constables exercising dispersal powers, interested members of the public and any later court.
4. The approach was illustrated by Parminder Singh v Chief Constable of the West Midlands Police [2005] EWHC 2840, where a broad description of alcohol-related anti-social behaviour and violent incidents was sufficient. An authorisation directed at a particular problem may also be used in relation to a previously unforeseen group, but that does not remove the requirement to specify the grounds.
5. The court therefore answered the first question in the case stated in the negative and did not determine the remaining questions. The conviction was quashed, with no remittal required.

• High Court (Administrative Court): The appeal by way of case stated was allowed. The court held that the authorisation was invalid and quashed the conviction.
• Sheffield Magistrates' Court: The Deputy District Judge convicted the claimant of knowingly contravening a dispersal direction issued under section 30(4) of the Anti-Social Behaviour Act 2003.