New CPS Guidance

One of the last things I did at the College of Policing was attend a meeting in London with the Crown Prosecution Service who had begun to review their guidance on the ‘prosecution of mentally disordered offenders’. The CPS issue prosecution guidance on a large number of topics, all publicly available on their website and they’d decided mental health guidance needed revising. First things first: the title of the old guidance sounded dated and pejorative by modern standards so I’m glad to find that new guidance gets rid of the term ‘mentally disordered offenders’.   Doesn’t get rid of the word ‘disordered’ but in fairness to the CPS, that is the term used in s1(1) Mental Health Act 1983 – “mental disorder is any disorder or disability of the mind and ‘mentally disordered’ shall be construed accordingly.”  The difficulty with all this, though, as Professor Jill PEAY points out in her (really quite wonderful) book “Mental Health and Crime” (2010), it’s not a straight-forward enterprise to determine a mentally ‘disordered’ offender from a mentally ‘ordered’ one.

So in October 2019, the CPS issued two new documents –

If you’re involved in criminal investigation in the police, you’ll need to read both of these.


In light of the number of discussions I had over the years with police officers, mental health and allied professionals as well as CPS themselves, I was glad to read this document because of what it says about ‘capacity’.  I’m going to over-focus on this specific point, to be honest because it’s the main problem I’ve seen repeatedly over the years and all professions and organisations fall in to the capacity trap!  In some of the discussions I’ve had, I will admit to some significant frustration about the times I would hear that investigation and prosecution is fairly straightforward because “it’s all about whether the person has capacity as defined by the Mental Capacity Act 2005”.

No, it’s not! – it never, ever was and it still isn’t … not really.

Capacity is, strictly speaking, not a ‘thing’ in criminal law – even to the extent that we use this word as a proxy term or metaphor for some other, quite complex matters, ‘capacity’ is not the determining variable. In other words, if a suspect does not have ‘capacity’ (whatever on earth that is meant to mean) but they’ve killed someone else, they’re almost certainly still going to be prosecuted for murder and the issue of mental illness, insanity or ‘capacity’ can all be untangled at court. Even if it were a less serious matter, it may still be necessary to prosecute the person because the legal issues inherent within this discussion are, ultimately, a matter for courts and even if someone is insane, unfit or seriously unwell, it may be the criminal courts still need to impose orders that only they control.  Prosecution is the only route to that, whether rightly or wrongly.

Equally, just because a suspect ‘has capacity’ it does not mean they must be prosecuted – the public interest test may still not be met even though the person knew what they were doing and knew what they were doing was wrong. All cases turn on their individual merits and circumstances.


There has been discussion about these matters in my own force over the last two weeks, as we ran training courses for the new ‘mental health tactical advisor’ concept being piloted. It is the area of policing and mental health which, in my own view, could do with the greatest effort by forces to improve their response. There are plenty of areas where I think the police are over-exposed on mental health related demands, but this is not one of them – history and public record shows we are under-involved, inconsistent and not always given the time and attention to investigations that we would give if those of us involved were not affected by our mental health.  The same is true of CPS who did research a number of years ago which suggested they under-prosecute where cases are referred to them by the police.

I think all organisations have been guilty over the years of over-focussing on this near-total red-herring – I’ve heard officers, nurses and psychiatrists say things like “he could be prosecuted because he has capacity!”  I’ve known officers argue against investigation and prosecution “because she lacks capacity” and intense discussion across professions about this stuff and CPS lawyers at the charging stage to decline to give a decision on prosecution, “unless the doctor provides a statement confirming they had capacity.” So what do these new guidelines say?!

The word ‘capacity’ appears five times in the suspects’ guidance: twice in the specific context of defences to murder, but otherwise purely to make the point that’s not really a valid way of looking at this stuff.  The main paragraph is in the section on information material available for a charging decision —

A request for evidence as to capacity, for example, lacks precision.  This term appears elsewhere in mental health law and in some criminal offences, it is not a term which makes clear whether it is focused on the evidence (the mental elements of a crime or a potential defence) or the public interest test.  A prosecution does not have to prove as part of the evidence the suspect’s capacity.  It implies that a prosecution would not proceed if the suspect lacks capacity: as will be discussed below, this may be the case but it may not be.”  

[The bold emphasis is mine.]


So now, we have clear and unambiguous guidance from the Director of Public Prosecutions:

It’s not a concept in criminal law, strictly speaking; and it’s certainly not correct that the Mental Capacity Act 2005 provides some kind of legal test that can be applied to criminal investigation and prosecution. We need to stop (over-) focusing on this as a determining variable or proxy decision-making tool for prosecution and start discussing, investigation and determining investigations properly! Criminal investigation remains (as it always did) about proving to the relevant standard the actus reus of the offence; the mens rea of the offence (which is not the same as the suspect’s mental health or capacity!) and then whether or not it is in the public interest to charge. The public interest test assessment may end up concluding that it is not necessary to prosecute someone despite the fact that we could. It may determine that someone serious and acute mental illness is no barrier to prosecution, because of the offence and / or background and / or context.

Essentially, the more serious the offence or background, the less relevant someone’s illness will be to determining the investigative and prosecution decisions. We can investigate and prosecute, the CPS can authorise a charge and all without having statements of evidence from doctors about whether someone ‘has capacity’.  Investigating officers should stand ready to refer clinicians and CPS lawyers to this guidance, as it’s still new and no doubt there are some people who need to read it and know it well, who don’t yet know it exists.

I didn’t, until last week.

(NB: there will be a separate post on the victims / witnesses guidance at a later date.)

Winner of the President’s Medal,
the Royal College of Psychiatrists.

Winner of the Mind Digital Media Award


All opinions expressed are my own – they do not represent the views of any organisation.
(c) Michael Brown OBE, 2020

I try to keep this blog up to date, but inevitably over time, amendments to the law as well as court rulings and other findings from inquests and complaints processes mean it is difficult to ensure all the articles and pages remain current.  Please ensure you check all legal issues in particular and take appropriate professional advice where necessary.

Government legislation website –