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Capacity and Consent: The Supreme Court's Ruling in A Local Authority v JB

By Kristen Palmer

Supreme court

Key Facts

JB, a 36-year-old man with autism and impaired cognition, was unable to comprehend neither the necessity of obtaining consent from a sexual partner nor that sexual activity without consent may amount to a criminal offence. Experts assessed that he posed a “moderate risk” of committing sexual offences, particularly towards vulnerable women. Mrs Justice Roberts from the Court of Protection, the first judge to hear his case, held that it would be discriminatory to require JB to understand consent before pursuing a sexual relationship because he would be dealt “a burden which a capacitous individual may not share”. This burden would have been an “unfair and unwarranted interference in his basic rights to a private and family life.”


A number of interesting principles were raised in the judgement. Firstly, Lord Justice Stephens clarified the scope of the concept of capacity within the Mental Capacity Act (MCA) 2005, particularly Section 1(4), stating that “an important purpose of the MCA is to promote autonomy[…] If P has capacity to make a decision then he or she has the right to make an unwise decision and to suffer the consequences if and when things go wrong. In this way P can learn from mistakes and thus attain a greater degree of independence.”

Secondly, the courts weighed the issue of individual autonomy against public benefit. He considered that the MCA and Court of Protection “do not exist in a vacuum but are part of a wider system of law and justice, and so must take into account the need to protect others”. He referred to the expert evidence identifying the risks that JB posed to women and the potential risks incurred by JB if he were allowed to pursue sexual relationships despite his inability to understand consent. The risks JB incurred included physical or psychological harm to others, especially relatives or friends of the potential victims, incarceration (which would likely result in ‘significant harm’ to his mental health) or hospitalisation. Lord Stephens ultimately reasoned that the “court for protection should have regard to reasonably foreseeable adverse consequences, with the aim of protecting members of the public as well as persons who may lack capacity” and dismissed the appeal.


This marked the first time the courts have been asked to decide whether and on what basis the law should act when someone without capacity asks for permission to act in a way that may harm others. The ruling was significant because it raised broader questions of what sexual consent should constitute, possibly leading to re-evaluation of many past cases.


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