PACE For Beginners – Part 1

If you’re a police officer, you can probably stop reading already – this one is not really for you! Now, if you’re a dummy … no, sorry: if you’re a mental health professional, then this is more-or-less at your request, whether or not you realise it. Incidentally, I don’t think you’re a dummy at all … perhaps I should just explain?! You’ll probably be familiar with the ‘…… For Dummies‘ series of books? Well, an AMHP / BIA on social media groaned aloud during a discussion that there wasn’t a volume PACE For Dummies edition, so this post is an attempt plug that market gap albeit for reasons of copyright and good manners we’ll call it PACE For Beginners!

Did I get away with that?! – it was all Aisling’s idea!

< Offstage: We don’t think you got away with it at all, if we’re honest! >

The Police and Criminal Evidence Act 1984, known by most police officers and lawyers who play with it as ‘PACE’, is the bedrock of much police procedure – covering such issues as stop & search, the granting and execution of search warrants (also affecting those issued under s135 of the Mental Health Act), detention in police custody including the issue of securing evidence by forensic samples, interviewing and commencing criminal proceedings against someone. It also covers the admissibility of evidence in criminal court proceedings. This post is the first of two which focus on the stuff that happens in custody after arrest. This first post aims to explicate the basic grounds for detention in custody and to the timescales which govern detention without charge. The second post covers the intricacies of detention for those who are detained. A third post (still under construction!) will cover how this all relates to the operation of the Mental Health Act 1983 (MHA).


First things first – the booking in procedure is a significant legal point because it does not necessarily follow that an arrest leads to detention being granted in custody. Whilst it is the arresting officer’s decision to take your liberty during a police incident, it is the custody sergeant  who is the key decision-maker once you arrive at a police station. I say custody sergeant as it is usually a sergeant who performs the statutory role of custody officer but there are some rare and unusual circumstances in which officers of other ranks perform this role. The custody officer is recognised in human rights and other law as an independent authority. They are there to govern the detention of those detained, cannot be involved in the investigation in any way and primarily charged with protecting the legal rights and ensuring the welfare of those detained.

The first legal question the custody officer must consider is whether there are grounds for further detention and this will depend what the person was arrested for. There are broadly five things –

  • Arrested in connection with an offence – see Evidence to Charge, below.
  • Arrested for a Breach of the Peace – can be detained to appear before the Magistrates to be ‘bound over’ to keep the Peace, or until the Breach of the Peace is over, whichever comes first. Those taken to court should be taken to the first available court sitting after their arrest.
  • Arrested under warrant – A warrant can be issued for anyone in connection with criminal proceedings (including rarely, for victims or witnesses) and allows detention in police custody until the person can be taken before the relevant court. I will also lump in offenders ‘recalled to prison’ under this category – detention until someone who is ‘on licence’ can be returned to a relevant prison.
  • Detained under Immigration Law – police officers or immigration officers can detain under this legislation and if investigation is still ongoing, someone can be detained for the purposes of that investigation. Where their immigration matters have been finalised and deportation is necessary, they can be detained in police custody once the IS91 document is served until removed to an Immigration Centre.
  • Detained under the Mental Health Act – custody officer can authorise detention at a police station for up to 24hrs as a Place of Safety under ss135 or 136 of the Act.  But only if an officer at the rank of inspector has authorised a police station to be used in exceptional circumstances.  Detention can be extended up to 36hrs on the authority of a superintendent and the doctor in charge of the person’s assessment.


Most commonly, individuals are arrested in connection with an alleged offence. This is where section 37 of PACE comes in – it requires the custody officer to decide upon arrival whether or not there is sufficient evidence to charge the person with the offence for which they have been arrested. It tells us that where the custody officer believes there is such evidence, they can detain. the person at the police station only for as long as it takes to do so.

Where there is insufficient evidence to charge, the custody officer may only authorise detention if that is necessary in order to secure and preserve evidence relating to the offence or to obtain evidence by questioning the suspect. These are the only two reasons to continue the detention of someone who is arrested where there is insufficient evidence. At all times whilst the suspect remains detained in police custody, the custody sergeant (also known as the custody officer) must have ongoing regard to this question of whether there is sufficient evidence to charge.

Section 34 governs the ongoing decision by the custody officer to keep someone detained without charge when there is insufficient evidence.  It requires the custody officer to release the person from custody as soon as the custody officer is aware that the original grounds for detention have ceased to apply. When released, the person shall be released without bail, unless investigation in to he allegation will continue, in which case he shall be released on bail (see below). If at any stage the custody officer is satisfied that there is now sufficient to charge, then the person may be detained under s37(7) for the purposes of charging them or taking CPS advice as to whether to charge (see below).


This is the fun and games: the timescales of detention – if you are an AMHP reading this post, it’s the equivalent legal topic to your intellectual wranglings over Nearest Relatives under s26 MHA for its potential simplicity but its apparent complexity in real situations.

  • Someone may be detained for 6hrs from the ‘relevant time’ – this is calculated as being their first arrival at a police station, OR 24hrs after their arrest, whichever comes sooner.
  • They suspect may be detained beyond 6hrs under section 40 of PACE where an officer not below the rank of inspector (known as the review officer) has granted further authorisation and they remain subject to the custody officer’s ongoing considerations under s37 and s34.
  • When an review officer completes such a ‘review of detention’ (see below), the person may be detained for a further 9hrs following which a subsequent review of detention must be undertaken by a review officer.
  • After two or more reviews, a maximum of 24hrs after the relevant time will be reached and the suspect must be charged with an offence or released from detention.
  • In serious cases, a police superintendent can authorise a further 12hrs beyond the 24hrs under section 42 of PACE where there remains insufficient evidence to charge.
  • Consideration to an extension of detention under s42 may be given at any time after completion of the second review under s40.
  • In complex cases, the police may present an uncharged suspect to a Magistrates Court who may grant a warrant under section 43 of PACE to extend detention by a further 36hrs period.
  • Finally, Magistrates may grant an a second warrant of detention under section 44 of PACE for a final 24hrs period – after this period the suspect must be charged or released without charge.
  • During all superintendent and Magistrate court extensions, custody officers continue to be bound by s37 and s34 of PACE and review officers at the rank of inspector must continue to review detention every 9hrs, under s40.

If you’re good at maths – you’ll have worked out that the maximum period you can spend in police custody without charge is 96hrs: the original 24hrs; plus the superintendent’s 12hrs; plus the Magistrates 36hrs; plus the Magistrates final 24hrs.


In practice, the first question asked by the custody officer is NOT the legal question of whether there is sufficient evidence to charge! – it is the question of whether there is any reason to think the person needs urgent medical attention. Questions around welfare loom large in police custody and are addressed within the Act itself as well as within the supporting Code of Practice. (PACE has eight Code of Practice, in all – it is Code C to PACE that is relevant to detention in custody.)

At all times, the custody officer must have regard to the welfare of detainees – paragraph 9.5 to Code C of PACE outlines that the custody officer must ensure that detainees receive appropriate clinical attention if they are “physically ill, injured, mentally ill or if they appear to need clinical attention.” This obliges the custody officer to call an ‘approved healthcare professional’ (distinct language in PACE, not to be confused with MHA terminology) if the person requires it and to call an ambulance if they require it immediately.

It needs to be constantly borne in mind that police custody is not a healthcare environment and at all times, detention is subject to an assessment of whether a detainee remains medically fit to be there – this is the custody officer’s assessment, and no-one else’s!


Where someone is removed from the custody block for hospital assessment or treatment, any time spent out of the custody area does NOT count towards the overall detention timescales – the relevant time is pushed back by exactly that amount of time although reviews remain necessary every nine hours after the first once becomes due.

For example –

  • 2200hrs on Day One – arrested for assault after allegedly punching someone.
  • 2215hrs – arrives in custody, relevant time will be 2215hrs on Day Two
  • 2225hrs – detention authorised, first review no later than 0425hrs
  • 2310hrs – seen by FME who advises that A&E assessment is required because of a query broken wrist.
  • 2350hrs – taken from police custody to nearest A&E.
  • 0415hrs – returns to police custody from A&E.
  • 0425hrs – first review of detention by the review officer. Had the person remain in hospital any longer, the review officer would still have had to undertake a review of detention by no later than 0425hrs.
  • Total time spent at hospital is 4hrs 25mins.
  • New relevant time is 0240hrs on Day Three.


An appropriate adult must be called for anyone in custody who is under the age of 18yrs of age and for any adult thought to be ‘mentally disordered or otherwise mentally vulnerable’. PACE Code C specifically states that the definition to be considered is section 1 of the Mental Health Act: “any disorder or disability of the mind”, quite a wide definition. It is a recent development following a legal challenge that 17yr olds are entitled to an appropriate adult. Most usually, this appropriate adult for a juvenile will be their parents, guardian or a social worker from a local authority.

An appropriate adults are otherwise defined as someone experienced in dealing with mentally disordered or otherwise mentally vulnerable people but who is not a police officer or employed by the police. Failing that, it can be any other responsible adult who is not a police officer, etc., etc.. However, appropriate adults cannot be witnesses or victims in the offence being investigated or people who have received admissions in connection with the offence under investigation. And whilst there is a statutory responsibility on local authorities to provide appropriate adults for juveniles who are detained in police custody where no other adult can be obtained. There is, alas, no corresponding duty on anyone to do so where the vulnerable person is a vulnerable adult.

A second post in this series covers the specifics of what happens can happen for some prisoners within the overall framework in this post that applies to all those who are detained.

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, 2019

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 –


2 thoughts on “PACE For Beginners – Part 1

  1. Firstly – This is a great idea to paraphrase as it were PACE for many reasons. However re AA T
    ..So why would we as a society give the right to distinguish people diagnosed with ill MH from those that are “mentally vulnerable” to police officers and healthcare workers – whilst they maybe compassionate they are not trained in the field of psychiatry, and therefore cannot be expected to make these decisions.
    We are all by its very nature “vulnerable” in custody,add complex MH or quite frankly any chronic MH diagnosis that can be triggered or escaloted by being detained and the criminal justice system thats a concoction for disaster This is precisely the reason ALL people with MH diagnosis were originally entitled to an appropriate adult during these times and in addition particularly if strip or intimate search is to take place. It was there for very obvious reasons, not only to protect the detained but also the credibility of investigation and the practices of all police personell.If someone asks for an AA and has diagnosed MH they should be given one, just because someone is assessed as being highfunctioning does not negate being vulnerable or the vital role of the AA. Changes to PACE CODE C seem to me to reflect more about our sparce resources and rising ill MH levels rather than what is best practice,or humane. It is an act of disability discrimination for police personell to judge certain behaviours in an individual in order to deem their vulnerability or not. #mentalhealthonthemighty

    1. The thing is, your characterisation here is quite right – either of the past or the present after changes. It is not correct, for example, that ALL people with a MH health diagnosis (or for that matter, children) were entitled to an appropriate adult for a strip search. It has always been the case during my 20-odd years service that if the urgent need for the search would put the person at risk by invoking delay to obtain an adult, it can proceed. Of course, where such urgency did not exist, then the delay must occur and the adult be obtained.

      Society would give the ‘right’ (it’s not a right the police or healthcare workers have claimed, it’s an obligation that society HAS, in fact, decided to give) to the police and healthcare workers because the blunt fact of the matter is: no-one else is there to do it. You don’t need to be trained in the ‘field of psychiatry’ to form a working view of whether someone may need more specialist assessment. And that’s all it is – it’s not the police making massive decisions about people and cracking on: if the police felt someone’s mental health *may* be such that they are vulnerable in custody, then all that means is they pause whatever can be paused and seek healthcare advice. The healthcare professionals in police custody are trained to screen mental health conditions for the purposes of determining whether even more specialist input is required and then there are NHS liaison and diversion services in most custody areas and all custody blocks have the ability to refer for a full Mental Health Act assessment.

      And on the point that everyone is vulnerable: if that’s true then paradoxically, no-one is. If someone with a mental health diagnosis asked for an appropriate adult in custody, they probably would be given one if one could be found, (depending only on the point they’d asked and the legal basis for them being in custody). And that last comment about availability is key: you should remember at all times, that no-one, anywhere has a legal responsibility to provide an appropriate adult for a vulnerable adult and the police are professionally barred from doing so. This means an occasional reality where an appropriate adult simply cannot be found despite police spending many hours begging services to help us out only to find repeated refusals.

      Final point: there is no mention of appropriate adults in the Police and Criminal Evidence Act 1984 (except for one brief mention in connection with intimate samples). The concept is defined and outlined in Code C which is a Code of Practice, this means the police are obliged to try to comply with its requirements but if that legitimately cannot or have a “cogent reason for” departing from its requirements, they are not breaking the law, regardless of the merits of anyone’s argument. This was made clear by the House of Lords (now the Supreme Court).

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