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Improving protections for vulnerable people in police custody

Dr Roxanna Dehaghani’s research investigated the Appropriate Adult safeguard and led to legislative reform and a revision of national standards.

An Appropriate Adult (AA) safeguards the interests, rights, entitlements, and welfare of vulnerable people in custody who are suspected of a criminal offence. The role of an AA is to ensure that a person in custody is treated in a fair and just manner and can participate effectively.

Person in handcuffs

In 2015, out of 297,000 detained police interviews with vulnerable adults, the AA safeguard was only implemented in 3% of cases. This means around 288,000 detained interviews took place without the appropriate safeguards in place.

Law lecturer, Dr Roxanna Dehaghani explored the underuse of the AA measure in the UK and set about improving the service for a range of stakeholders including the police, the network that implements the scheme and the vulnerable people who benefit from it being in place.


The Police and Criminal Evidence Act 1984 (PACE) Code C is at the centre of all work connected to the AA safeguard. It sets out the rights of adult suspects detained in police custody and states that police custody officers should obtain an AA for all vulnerable suspects, including those who have a mental illness, learning disability, brain injury or autism spectrum condition.

Without the support of an AA, suspects may have difficulty understanding their rights, become confused, provide unreliable information, or be suggestible or acquiescent.

Dr Dehaghani’s research, beginning in 2017, uncovered limitations of PACE Code C, including the definition and identification of vulnerability, and a lack of incentives for implementation.

Working with the Police

Dr Dehaghani conducted the first systematic examination of why the AA safeguard was often not implemented in police interviews.  

Observing and interviewing police custody officers from two forces over a six-month period, Dr Dehaghani identified that:

  • PACE Code C failed to clearly define how or why a suspect might be considered vulnerable.
  • The wider effects of detention in police custody and the process of criminalisation were often not considered when assessing an individual.
  • Officers reported that they tended to rely on a ‘hunch’ to detect vulnerability and were not always confident in their judgements.

Working with National Appropriate Adult Network (NAAN)

NAAN, the national infrastructure for the coordination and provision of AA, invited Dr Dehaghani to compile the first evidence base to conceptualise the safeguard and the AAs role in developing effective support.

Dr Dehaghani provided new findings and insights on how vulnerability could be better identified in critical safeguarding legislation and set out what the key functions of an AA in law and practice should be.

The research underpinned NAAN's revision of its National Standards in 2018. The Standards provide clear guidance and best practice for effective AA supervision and have also underpinned the creation of a new self-assessment tool for commissioners and providers of AA services.

Working with the Home Office

Dr Dehaghani was the only legal academic to sit on the Home Office Working Group on Vulnerable Adults, tasked with reforming PACE Code C. The Group’s contributions were used to produce a new version of the code for public consultation in October 2017.

Dr Dehaghani’s recommendations were reflected in changes made to the final PACE Code C published in 2018.

Why is the research important?

PACE Code C states that vulnerable adult suspects and children should be accompanied by an AA. However, out of an estimated 850,0000 adult suspects detained in police custody each year, 39% have a mental disorder, including mental health and learning disabilities.

Independent research has shown that vulnerable adults who received the safeguard “felt supported emotionally, and more protected against mockery, intimidation, fear, dehumanising, bullying and isolation”. The safeguard also leads to greater integrity, a better quality of evidence, and a decreased risk of miscarriages of justice.

Dr Dehaghani’s research positively impacts the vulnerable people who require AA support, the police who utilise the safeguard, and NAAN, the network that coordinates and implements the scheme. Her work not only influenced legislation in England and Wales it also led to the creation of new Standards to improve the quality and accessibility of the AA service.

Key stats

The Standards have been used extensively by AA in England, Wales, Northern Ireland and the Isle of Man. A survey in 2019 found:

  • 91% of respondents had used the Standards and 90% found them effective.
  • The Standards are considered the ‘most effective’ of NAAN’s products and services by those who had been a member for under 12 months.
  • 62% of respondents had used the new self-assessment tool and 96% found it effective.

Meet the team

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