Doli Incapax in UK Law

But if criminal proceedings are begun and the defence raises any of the capacity issues, how should the court proceed? However, although the jurisdiction exists, I think that it will be in only exceptional cases that it should be exercised, on the ground of one or more of the capacity issues, before any evidence is heard.

This is an issue which the court has to decide, not the doctors, although of course the medical evidence may be of great importance. But, the medical evidence must almost always be set in the context of other evidence relating to the child, which may well bear upon the issues of his understanding, mental capacity and ability to participate effectively in a trial. It is the court's opinion of the child's level of understanding which must determine whether a criminal trial proceeds.

Accordingly, it is my view that, in most cases, the medical evidence should be considered as part of the evidence in the case and not as the sole evidence on a freestanding application.

If the court decides that it should call a halt to the criminal trial on the ground that the child cannot take an effective part in the proceedings, it should then consider whether to switch to a consideration of whether the child has done the acts alleged (the fact-finding process), under the procedure referred to in the Barking case. It is clear since Re H (see above) that the fact that a child cannot take an effective part in the fact-finding process does not infringe his Article 6 rights.

When Parliament confers a discretionary power exercisable from time to time over a period, such power must be exercised on each occasion in the light of the circumstances at that time. In consequence, the person on whom the power is conferred cannot fetter the future exercise of his discretion by committing himself now as to the way in which he will exercise his power in the future.

In his long dissenting judgment, which has stood the test of time better than the judgments of the majority, Brett J said that on all the cases he had reviewed he thought it was proved that there could be no conviction for crime in England in the absence of a criminal mind or mens rea, and that a mistake of facts, on reasonable grounds, to the extent that if the facts were as believed, the acts of the prisoner would make him guilty of no criminal offence at all, was an excuse, and that such excuse was implied in every criminal charge and every criminal enactment in England.

Surprising though it may seem, such errors do occur in particular in connection with repealed legislation. That would fall comfortably within the language of mistake. We would not exclude the possibility that section 142(2) would be apt to deal with a case in which circumstances developed after a guilty plea and sentence which led the prosecution to conclude that the conviction should not be sustained.