Liaison and Diversion

I’ve been trying to think how to draw a one-page diagram of how I think Liaison and Diversion should work for several years!  Bearing in mind that nationally, we don’t have an agreed model on this and my previous views that some models we have seen miss the (legal) point however good they may be on health.  Given that NHS areas will vary in the nature and amount of investment they can make in terms of either money or staff, etc.; and given that police decision-making has to occur regardless of how good / bad that investment is, I came up with this which I’ve shared with various colleagues and with the CEO of Revolving Doors, Dominic WILLIAMSON is working in this field –

Liaison&Diversion**  Explanatory note – indicatable offences are the more serious ones, triable in the Crown Court.  Summary offences are comparatively minor, triable in the Magistrates’ Courts.

I’ve written before that in practical terms, in most areas, the single factor which triggers whether or not someone arrested for a criminal offence and suspected to suffer from a mental illness, is prosecuted into the justice system or diverted from it to the health system, is whether or not they are ‘sectionable’ under the Mental Health Act.  In other words, whether they require hospital admission in connection with their mental health problem.

The issue that arises from this de facto approach, is that the Mental Health Act is designed to operate with someone mentally ill patients being prosecuted so that the criminal courts can balance the important issues of their individual right to treatment and care with any prevailing public protection issues.  In other words, someone being sectioned under section 2 or 3 MHA may not be sufficient to ensure public protection, if that person has, for example, killed or seriously injured someone.  Equally, prosecuting someone for stealing ten pounds worth of food after living rough and in crisis for several days would probably not be in the public interest if they pose no risk to anyone and are in need of admission for acute mental health problems.

We need a balanced approach – not least because, in reality, a lot of cases are in between those extremes and are set against complex personal and social backgrounds.  The above hypotheticals are easy to conceive – reality is endless shades of grey and decisions needed may be about taking the least worst option available, rather than an ideal solution.

But to get there, we will need input to and output from the health system and we need the involvement in the criminal justice system for a few.  How do we get the balance?

Well I submit a model in which there are broadly four circumstances we consider:  serious or non-serious offending with either acute or non-acute illness.  Against those four combinations, we will either be dealing with a person who, in terms of their criminal and mental health antecedents either poses a “bail risk” or does not.  So you have eight situations – see this diagram.


My contention is, that the severity of the crime alleged and the gravity of someone’s illness should determine a way forward, with their treatment and care for their illness taking the immediate priority, unless that would compromise public safety.  This seems to balance off the considerations involved.  “Police bail criteria” from s38(1) Police and Criminal Evidence Act 1984 provides a useful framework to determine whether pausing the criminal justice process would be proportionate and wise – I suggest it most usually would be wise to do so where a suspect potentially has complex needs.  The criteria are –

  1. His name or address cannot be ascertained or the custody officer has reasonable grounds for doubting whether a name or address furnished by him as his name or address is his real name or address;
  2. The custody officer has reasonable grounds for believing that the person arrested will fail to appear in court to answer to bail;
  3. In the case of a person arrested for an imprisonable offence, the custody officer has reasonable grounds for believing that the detention of the person arrested is necessary to prevent him from committing an offence;
  4. In a case where a sample may be taken from the person under section 63B below, the custody officer has reasonable grounds for believing that the detention of the person is necessary to enable the sample to be taken from him;
  5. In the case of a person arrested for an offence which is not an imprisonable offence, the custody officer has reasonable grounds for believing that the detention of the person arrested is necessary to prevent him from causing physical injury to any other person or from causing loss of or damage to property;
  6. The custody officer has reasonable grounds for believing that the detention of the person arrested is necessary to prevent him from interfering with the administration of justice or with the investigation of offences or of a particular offence; or
  7. The custody officer has reasonable grounds for believing that the detention of the person arrested is necessary for his own protection.

So let’s try to get a process where we ask health to do two things to support all this police decision-making:

  • Have input into the process which assist the police in identifying more people in custody who may have mental health disorder or history.
  • Have input into the decisions which will be taken in slow time, through the use of police bail, about whether it is in the public interest to charge someone with an offence if they have a history of mental health disorders. << This is provision of information and opinion; not taking the decision which would always remain a CJ prerogative for police / CPS.

How areas achieve these two things, is the challenge of Liaison and Diversion, but it could be as simple as a properly established phone-call mechanism between the police and mental health –


When a person is booked into custody, if there are no mental health nurses based in custody to screen everyone – we know areas struggle to achieve this because of cost – why not ask the custody staff to ring a Mental Health Trust professional and give the name, date of birth and address of the suspect along with confirmation of whether the police / FME have reason to suspect a mental health disorder?

All we’d need back from the NHS in the phone call, is confirmation of whether they are now going to respond to custody and see the person.  This would obviously occur if the police / FME had reason to have concern AND / OR if the Mental Health Trust knew that the person is or has been a mental health patient and they could vary by time of day who might respond:  CrisisTeam for those who are not known and those arrested out-of-hours; patients CMHT / AOT in office hours?  Obviously, those for whom there are no concerns and who have no mental health history would not need to be seen and this makes it a cheap and easy way of doing something, even in areas with few resources.  And! – it has nothing to do with breaching anyone’s confidentiality because the details of those who were not known to the MH trust would not be retained by them unless they subsequently became a patient.  The police would initially be told little, until the initial screening had taken place and the outcome needed to feature, if relevant, in the police’s decision-making.

The reasons this is important, is because when you let the police try to identify prevalence amongst those arrested, you get a number between 10-15%.  In some areas, as many as 50% of those arrested either are known, were known or need to be known to the mental health trust.


So, the arrested person had a pause placed on their investigation in order for a multi-disciplinary meeting to occur to share information and reach a more balanced view about the prosecution decision.  We need input into this from health and areas just need to work out where this comes from.  But are we saying that in the fifty-eight mental health trusts in England, they can’t identify one or two staff to sit down with the police once a month for an hour or so and discuss about six to ten people?  My research indicates in a busy custody area, that is roughly the demand that would arise from this model.

The more I think about Liaison & Diversion, the more I think you could do good things, for relatively little, even if you keep working out where you can get money from to do great, even better things.  And the benefit for the police, is that the model I’ve outlined above, can be operated regardless of how much or how little input the NHS are able to give in your area.

IMG_0053IMG_0052Winner of the President’s Medal from
the Royal College of Psychiatrists.

Winner of the Mind Digital Media Award.



7 thoughts on “Liaison and Diversion

  1. I think your blog is brilliant! I have just returned from Wales and I have just done a blog about my terrible experience. It is shocking what is going on under the mental health and in the middle is a vulnerable person – it is so very sad. I have documented this in my blog. I wish the police could be involved in a more positive way than just arresting someone. That is why I myself wanted to be a police officer.

  2. Michael – thanks for this. It is very helpful and interesting to see the respective roles/responsibilities of NHS and criminal justice services in relation to Liaison and Diversion outlined in a flow diagram.

    However, I think that there is something else which needs including/factoring into the model – the delivery of holistic, social care and housing services. In my experience as a practitioner and latterly a development worker in L&D, it is exactly these services which are essential in helping to stabilise the lives of many people experiencing mental health crisis and coming into contact with the justice system. They are also particularly important for people with multiple problems or ‘dual diagnosis’, and for those whose mental health needs are assessed as not being sufficiently severe to warrant input from statutory mental health services. However, frequently they are not the ‘gift’ of the health sector.

    I have been meaning to put down my thoughts about the importance of holistic and social care interventions in Liaison and Diversion for a while – if you wanted, I would be happy to write down something for a future blog post.

    Best wishes, Rob

    1. Rob, please do – I’d happily publish them and your feedback is welcome and, as ever, spot on. I guess being the policeman, all that “stuff” is in the left hand column … whatever or however we improve that aspect of assessing and providing for need, it should have input and output at those points mentioned, but totally agree it’s about determining what that looks like versus what is possible / affordable.

      Hence my deliberately rather vague left hand column, because different areas have different views / resources. But you are, of couse, quite correct.

      1. Great – I’ll put some thoughts together. Liaison and Diversion seems for the first time ever to be having its moment in the limelight – but a challenge to come will be how to make L&D and all the other initiatives taking place (street triage, NHS commissioning of custody healthcare, S136 places of safety etc) comprehensible to both front line Police officers and the people who will access these services. Will be back in touch soon …

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