Personal Injury, Serious Injury & Clinical Negligence

Capacity and Crime – developments in the legal test for mental capacity in the criminal justice system


It is now over a decade since the Mental Capacity Act 2005 (MCA) was introduced. At its heart was a new test for determining whether any individual was capable of taking decisions regarding aspects of their own life.

The MCA has not been without its critics particularly in relation to the assessment process itself. It is, however, currently applicable in England and Wales in respect of assessing an individuals mental capability save in respect of one very important area.

Those charged with a criminal offence cannot rely upon an assessment of incapacity under the MCA either as a defence to a charge or as an indication that they are unfit to stand trial.

The legal tests currently utilised to determine those issues within the criminal courts jurisdiction both remain rooted in the common law and date back to the early part of 18th century.

Despite judicial adeptness in applying those tests to reflect changes in jurisprudence and medical understanding they remain fundamentally anachronistic and furthermore probably fail to serve well either society or the individual charged due to their attendant limitation on disposal and sentencing.

The Law Commission consultation

The Law Commission recognised this unsatisfactory situation and in 2008 commenced a process of consultation to look at this issue.

Originally conceived as a joint project the Commission has subsequently confined itself to examining the test for ‘fitness to plead’ only in the first instance. Formal consultation was commenced in 2010 and Commission’s report was scheduled for publication in November 2015 but in fact became available on the 13th January 2016.

For those interested in the development of the law relating to capacity one of the primary considerations was whether the Commission would look to the MCA for potential application within the criminal justice system.

The Commissions report is substantial running to some 340 pages in part one. The second part comprises draft legislation the aptly named ‘Criminal Procedure (Lack of Capacity) Bill’ (the Bill).

The recommendations

So what is the commission recommending?

First, that there is an underlying presumption of capacity which accords with the approach in the MCA.

There are slightly different provisions for cases proceeding through the Crown Court and the generally less serious matters that are dealt with in the Magistrates Courts.

In the Crown Court capacity is to be determined by the Court without input from a jury and the evidence provided to assist the Court will come from reports produced by at least two doctors, psychologists or other ‘suitably qualified persons’ (suitable qualification is yet to be defined).

The Commission recommends a two level test (i.e. the two issues using MCA parlance).

First does the Defendant have capacity to participate effectively in a trial; and

Second, does the Defendant have capacity to plead guilty.

The applicable tests are set out in clause 3(3) on effective participation and clause 6 (2) on guilty plea, and are as follows:

‘Are the Defendants relevant abilities when taken together sufficient to enable the them to participate effectively in the proceedings; either

On the offence or offences charged’ – c.3(3);


In a hearing where there is a guilty plea or change of plea’ – c.6(2).

Relevant abilities are defined within c’s 3(4) and (5) and 6 (4) and (5).

The tests differ largely in respect of the ability to understand the trial process and give evidence neither of which is necessary where a guilty plea is tendered.

Clauses 3(5) and 6(5) however are identical and require in particular that the Defendant has:

  • An ability to understand information relevant to the decision,
  • An ability to retain that information,
  • An ability to use and weigh that information when making a decision,

(d) An ability to communicate the decision.

Those familiar with Clause 3 (1) of the MCA will immediately identify the similarity in the language used.

The burden of proof falls upon the party raising the issue and the standard of proof will generally be the ‘balance of probability’

There is provision within the bill to delay any determination of capacity if there is a prospect of recovery and for reassessment of capacity if during the proceedings it might have been regained.

For proceedings within the Magistrates Court the Court can accept written or oral evidence of two or more persons one of whom must be a doctor.

There is again provision for separate assessment of capacity to participate in a trial or to plead guilty, however, the tests set out at c. 32(4) and (5) and c. 35 (4) and (5) are broadly similar to those applicable in the Crown Court and such changes as there are relate primarily to the differences of procedure in the respective Courts.

There is a great deal more in the bill of course much of it dealing with the Courts powers on disposal and sentencing of defendants. This article however is not aimed at those whose main interest is criminal procedure but rather the wider development of the law relating to the assessment of capacity beyond the MCA.

What now?

Whether and when this bill will come before Parliament remains to be seen.

There is one further issue arising from this report. As indicated earlier the commission embarked on the consultation process with the intention of examining not only the test in respect of fitness to plead but also the defence of ‘insanity’.

In short a defendant might currently be found to be fit to take part in a trial but then successfully plead that, due to mental incapability they were not guilty of the offence charged.

It might have been expected therefore that the Commission would go on to examine the test for ‘insanity’ and in due course bring forward proposals that would update the test along similar lines to those now proposed in the current Bill.

They may yet do so, however the Bill does contain reference to the current defence of insanity and it is supposed therefore that the expectation is that any review of the insanity defence will postdate the enactment of this Bill. That in itself suggests to the writer that it is unlikely to happen very soon.

Finally in embarking on this exercise the Commission had the benefit of a wide range of views in relation to the operation of the MCA in practice. It will be interesting to see to what extent that data is utilised for the purpose of amending the MCA in the future.

Contact our specialist serious injury and medical negligence department

Martin Pettingell, Head of the Serious Injury and Clinical Negligence Department at Clarke Willmott LLP.

Martin is a Court appointed Deputy, Chairman of the brain injury charity Headway Somerset and an expert in issues arising from brain injury and the loss of mental capacity. For further advice contact Martin on 0117 305 6256.