What place has 'capacity' in the criminal law relating to sex post JB?

The term 'capacity' has come to assume a variety of meanings in the law of England and Wales, and the failure of statutes and judges to specify its meaning and application across the civil and criminal law leads to problems. Nowhere is this perhaps clearer than in the law relating to sexual capacity. This paper begins with an overview of two streams of law on sexual capacity in the civil and criminal law. The first stream traces through the criminal law provisions of the Sexual Offences Act 2003, the work by the Law Commission which led to its enactment, and the ways in which its provisions have been applied by the courts in practice; and the second examines the Mental Capacity Act 2005 ('MCA 2005') and its parallel application by the civil courts. We illustrate how the case of A Local Authority v JB [2021] UKSC 52 brought these problems to the fore, as the Supreme Court was at last confronted with the differences between the definition and use of the term 'capacity' by the civil and criminal law on sexual capacity. We suggest that the decision made by the Supreme Court in JB has left open terrain which ought to be used to reframe, or perhaps even replace, the concept of 'capacity' within the criminal law on sexual capacity.¹.