In July 2012, the Law Commission published a Scoping Paper to find out how the criminal defences of insanity and automatism operate in practice.  The responses to that paper have informed  a Discussion Paper  that has just been published.  The paper is of particular interest for its suggestion there should be a move to a defence of lack of criminal capacity, and for the discussion of how such a lack of criminal capacity overlaps with/differs from a lack of capacity as understood for purposes of the MCA 2005. 

As the Law Commission puts it in their summary:

We think that people should be exempted from criminal responsibility for an offence if they lacked all criminal capacity, which means that they could not have avoided committing the crime they are charged with because of a mental disorder or a physical disorder. In other  words, people who totally lacked capacity not to commit the crime charged, because of a medical condition and through no fault of their own, should have a defence.

This defence would extend to cover not solely those who would satisfy the diagnostic criteria for purposes of the MCA 2005, but also those suffering from physical disorder.   A lack of criminal capacity would arise where a person lacked the capacity (1) to make a judgment rationally; (2) to understand that what they are doing is wrong; or (3) to control their bodily actions, and in each case would require that the incapacity be the result of a qualifying recognized medical condition.  That capacity would (in similar fashion to the definition under the MCA 2005) be issue and time specific.   Successfully establishing this defence would not lead to acquittal, but rather to a special verdict and disposal, for instance, by way of a hospital order.

Consistent with the scope of the new proposed defence, there is also a proposal that the defence of automatism should only be available  where there is a total loss of capacity to control one’s actions which is not caused by a recognised medical condition and for which the accused was not culpably responsible. A person who successfully pleaded automatism would be simply acquitted.