McMahon v Independent Office for Police Conduct

Permission to appeal from a judicial-review permission decision requires a real prospect of success or another compelling reason. Judicial review examines the legality of the decision-making process, not whether the underlying decision was right on the merits. Disclosure is exceptional and must be necessary to resolve a particular public-law issue fairly and justly. The material must bear on the decision under challenge and the information considered by its decision-maker. Later evidence of conflicting accounts or unreliability does not itself establish public-law error. The limited remit of a police-complaints oversight body must also be respected.

The claimant challenged the Independent Office for Police Conduct’s decision to refuse a review of a Greater Manchester Police reinvestigation into complaints concerning the handling of domestic-abuse allegations and a request for disclosure under Clare’s Law.

Mrs Justice Lang refused permission to apply for judicial review and refused specific disclosure in [2024] EWHC 556 (Admin). The claimant sought permission to appeal, alleging errors concerning disclosure, procedural fairness, missing body-worn video evidence and the assessment of the police investigation. The central issue was whether any proposed ground had a real prospect of success or whether there was another compelling reason for an appeal.

Application refused. Lady Justice Andrews held as follows.

1. Permission threshold. Permission to appeal required a real prospect of success or some other compelling reason for an appeal to be heard. The latter category usually concerns a point of law of wider public importance. This was not such a case. The court therefore had to consider whether the High Court judge had applied the correct legal principles, considered the relevant evidence and reached a conclusion reasonably open to her.
2. Judicial review and disclosure. Judicial review concerns the process by which a public body reaches a decision, rather than the merits of whether it was right or wrong. Disclosure is rarely ordered in judicial review. It should be ordered only where necessary to deal fairly and justly with a particular issue. The requested footage concerned matters outside the investigation reviewed by the IOPC and was not necessary to determine whether the challenged decision contained a public-law error.
3. Decision-maker’s material. The court ordinarily assesses the lawfulness of a decision by reference to the material before the decision-maker. It should not evaluate evidence that played no part in the challenged decision, save in exceptional circumstances. The High Court was entitled to find that the IOPC had neither possessed nor viewed the relevant footage and to refuse disclosure.
4. Evidence and public-law error. Complaints about conflicting evidence, administrative error or the reliability of police accounts were merits arguments unless they showed that the decision-maker considered irrelevant matters, failed to consider relevant matters or acted irrationally. Evidence said to demonstrate unreliability only after the decision could not establish an arguable public-law error where the decision-maker had no clear evidence of unreliability before it.
5. Fairness and the IOPC’s remit. The late witness statement was admitted and considered, and no party was prejudiced. Although counsel’s interruptions were unacceptable, the judge intervened and allowed the claimant to complete her submissions. There was no arguable procedural unfairness or breach of Article 6 of the European Convention on Human Rights. The IOPC’s limited function was to assess whether the police complaint investigation was reasonable and proportionate; it was not required to conduct a fresh criminal investigation or decide the merits of the underlying allegations.
6. None of the grounds had a real prospect of success. Permission to appeal was refused on all grounds.

• Court of Appeal (Civil Division): Permission to appeal was refused on all grounds.
• High Court of Justice, King’s Bench Division: Mrs Justice Lang refused permission to apply for judicial review and refused specific disclosure in [2024] EWHC 556 (Admin).