An, R (on the application of) & Anor v Secretary of State for the Home Department & Ors

The civil standard of proof is a single standard: proof on the balance of probabilities. Its flexible application requires stronger and more cogent evidence where an allegation or its consequences are serious; it does not create an intermediate standard or require proof akin to the criminal standard.

A Mental Health Review Tribunal should apply that standard to all questions arising under sections 72 and 73 of the Mental Health Act 1983. It has particular practical importance for disputed facts. For evaluative judgments about the appropriateness and necessity of detention, it forms the backdrop to the tribunal’s assessment of all the evidence and argument.

The statutory detention criteria in section 72(1)(b) are cumulative. A patient must be discharged if the detaining authority fails to satisfy the tribunal as to either criterion.

AN was detained under a hospital order and restriction order. In 2004 the Mental Health Review Tribunal refused to direct his discharge under section 73 of the Mental Health Act 1983. It preferred evidence that he continued to suffer from a treatable psychopathic disorder, that hospital detention remained appropriate, and that it was necessary for protection and treatment.

AN sought judicial review, contending that the tribunal had adopted the wrong standard of proof. Munby J dismissed the claim: [2005] EWHC 587 (Admin). He held that factual issues attracted the ordinary civil standard, while evaluative questions of appropriateness and necessity were not susceptible to a defined standard of proof.

The appeal concerned the applicable standard, whether it governed all statutory issues, and the proper discharge consequences where the detaining authority failed to establish a criterion.

1. Appeal dismissed. The tribunal’s only misdirection was favourable to AN: it had used a standard akin to the criminal standard for important factual issues. That error could not assist him.

2. English law has one civil standard of proof: the balance of probabilities. Following In re H (Minors) (Sexual Abuse: Standard of Proof) [1996] AC 563 and Secretary of State for the Home Department v Rehman [2003] 1 AC 153, there is no intermediate standard between that test and the criminal standard. The standard is flexible in application because serious allegations or serious consequences ordinarily require more cogent evidence before a tribunal can find the matter proved. The degree of probability required remains more likely than not.

3. For continued mental-health detention, cogent evidence is required but no heightened evidential threshold beyond that. The interests in avoiding unjustified detention must be balanced with the patient’s interests in treatment and the risks to the patient and the public arising from an unwarranted release.

4. The balance-of-probabilities standard applies to all questions under sections 72 and 73. It applies directly to disputed facts, including mental disorder, its nature and degree, and past conduct. Questions of appropriateness, necessity and future risk remain evaluative judgments, so the standard will usually play a less prominent practical part. Nevertheless, it provides the appropriate backdrop to the whole decision-making process and avoids an artificial division between fact and evaluation.

5. This approach complies with article 5 of the European Convention on Human Rights. Proof on the balance of probabilities supported by cogent evidence can satisfy the requirement that mental disorder be reliably shown.

6. Munby J’s description of the statutory default position was incorrect. The criteria in section 72(1)(b)(i) and (ii) are cumulative. The tribunal must direct discharge if the detaining authority fails to satisfy it as to either criterion. The mistake was unnecessary to the earlier decision and did not affect AN’s case.

• Court of Appeal (Civil Division): Appeal dismissed. The court corrected parts of Munby J’s reasoning but upheld the dismissal of the judicial review claim: [2005] EWCA Civ 1605.
• High Court, Administrative Court: Munby J dismissed AN’s judicial review challenge to the Tribunal’s refusal to direct discharge: [2005] EWHC 587 (Admin).