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Harm reduction unit

An integrated risk management service for cases of stalking and other potentially dangerous persons.

First published

Key details

Does it work?
Criminal justice
Violence against women and girls
Violence (other)
Vulnerability and safeguarding

David Thomason

Email address
North West
Criminal justice (includes prisons, probation services)
Health services
Voluntary/not for profit organisation
Stage of practice
The practice is implemented.
Start date
Scale of initiative
Target group
General public


This initiative aims to:

  • protect life and property
  • preserve order
  • prevent the commissioning of offences
  • bring offenders to justice
  • support the requirements of the Victims' Code
  • support the effective management of risks associated with potentially dangerous persons
  • provide intervention to reduce risks associated with imminent violence, violence, problem behaviour persistence, reoccurrence of a problem behaviour and risk of psychosocial damage to individuals
  • provide practical, emotional and psychological support to the victims of potentially dangerous persons
  • assist with the referral, exchange and gathering of information to assist the management of risk
  • facilitate intervention by the relevant agencies as early as possible
  • contribute to ongoing effective risk management and compliance with statutory requirements
  • strengthen and nurture the liaison between agencies

Intended outcome

  • Reduce reoffending for perpetrators.
  • Increase confidence by perpetrators that they have the tools to address problem behaviours.
  • Increase perpetrator satisfaction with the bespoke intervention provided.
  • Increase victim satisfaction with the sentences given to perpetrators.
  • Increase victim satisfaction with support provided to them.
  • Improve responses to stalking as a crime type.
  • Improve responses to potentially dangerous persons (PDPs).


The Cheshire Harm Reduction Unit (HRU) is an evidence-informed service. Referrals into the service, their journey and outcomes are recorded from the point of entering the pathway, and in accordance with the information sharing agreement.

HRU operational model

The HRU is a collaborative service, delivered by integrated Criminal Justice and NHS partners. The primary integrated partners are Cheshire Constabulary, Cheshire and Wirral Partnership NHS Foundation Trust, the Probation Service, and Mersey Care NHS Foundation Trust.

The HRU employs a proven integrated working model to address risks associated with PDPs to protect victims. The HRU manages and complements the management of threat, harm and risks associated with PDPs who engage in repeated problem behaviour in Cheshire. Problem behaviours are often complex behaviours that cause harm to the subject or perpetrator and/or others.

The HRU needs to be highly selective and focused regarding the nature and degree of interventions in any particular case. This is to ensure that limited time and resources are invested for maximum impact where the most value will be added.

It is recognised that risk management is improved when direct therapeutic or advocative work is undertaken with a ‘critical few’ perpetrators and victims. Determining the viability for the HRU delivering such interventions is assessed on a case-by-case basis, using the most contemporary knowledge, skill, experience, and evidence available.

Potentially dangerous persons (PDPs)

The College of Policing defines PDPs in authorised professional practice (APP) as:

a person who is not currently managed under one of the three multi-agency public protection arrangement (MAPPA) categories, but reasonable grounds exist for believing that there is a risk of them committing an offence or offences that will cause serious harm.

The HRU considers the risk of harm relating to the occurrence or recurrence of behaviour that is harmful to self and others. The nature of harm can include serious physical, psychological and emotional harm. This definition does not prevent the HRU complementing the management of risk in multi-agency public protection agencies cases or other cases already subject to multi-agency or other risk management forums and interventions.

The expertise and diverse competencies from within the unit (provided by the range of professionals and organisations involved) contributes to effective risk management of cases.


Uniquely, access to the HRU is not dependent on diagnosis or classification of an underlying mental disorder (in the widest sense of the term) or psychopathology. However, it is recognised that specific problem behaviours can be associated with underlying disorders such as psychosis, atypical neurology, personality, intellectual disability, emotional disturbance, and substance abuse. These require consideration when undertaking risk assessment, providing consultations and planning diverse interventions to manage risk.

Intervention from the HRU is dependent upon the nature and degree of the presenting problem behaviour, as well as the nature of the risks associated with the presenting behaviours. Intervention by the HRU is dependent upon assessed 'added value' by HRU input.

Operational concept

The HRU is a needs-led, risk-informed service provider, framed within a psychosocial and legal framework. Risk is seen as dynamic in nature and responsive to individual vulnerabilities that interact with situational/social factors. It is this interaction that manifests in the interpersonal problem behaviours of stalking or domestic violence. It can represent a range of risk – both psychological and emotional as well as violence – to known and unknown victims.

Risk assessment identifies the presence (or absence) of risk factors in individual cases of problem behaviours, and formulation or explanation of how these risk factors interact. This informs the design of needs-led risk, risk-sensitive intervention and management plans. The HRU describes an intervention as any activity by the HRU that directly or indirectly targets risks correlated to an individual case.

Operational history

Operational modelling of the HRU corresponds with and evolves from the nationally evaluated Integrated Anti-Stalking Unit (IASU) for Cheshire. This formed one of three local area partnership sites underpinning the multi-agency stalking initiatives programme (MASIP) project. The aim of the IASU was to mitigate risks and impact of stalking on victims. It did this by providing needs-led, risk-informed interventions to support victims and provide appropriate interventions to perpetrators.

Geographical remit

The HRU operates where the alleged perpetrator or victim usually resides within the Cheshire Constabulary geographical area. This is made up of the four unitary authority areas of Warrington, Halton, Cheshire East and Cheshire West, and Chester.

The degree and nature of HRU input is determined by the source and nature of the complaint or request made, and the outcome of the risk/threat assessment process.

Resources and staff composition

The HRU integrates the skills, competencies, knowledge and authorities of staff from all organisations to inform management of risks associated with identified PDPs. This includes Cheshire Constabulary, the Probation Service, Cheshire and Wirral Partnership NHS Foundation Trust, and Mersey Care NHS Foundation Trust.

The HRU uses a diverse range of interventions, including legal deterrents and therapeutic intervention when indicated.

The governance of the HRU is led by Cheshire Constabulary, with overall operational responsibility lying with the detective superintendent for safeguarding.

The full time dedicated HRU staff consists of:

  • a detective sergeant (Cheshire Constabulary)
  • three constables (Cheshire Constabulary)
  • a consultant forensic psychologist (Mersey Care NHS Foundation Trust)
  • two clinical practitioners (a senior psychiatric nurse and a specialist occupational therapist from Cheshire and Wirral Partnership NHS Foundation Trust)
  • two specialist victims advocates (Cheshire Constabulary)
  • a business support officer (Cheshire Constabulary)

The Probation Service aligns dedicated staff covering the three probation delivery units (North, East, West) to perform the role of HRU single point of contact (SPOC). It facilitates information sharing and risk management involving persons on probation or those likely to become a person on probation.

Cases that have received therapeutic interventions are reviewed at least at quarterly intervals to monitor any improvement or deterioration in their risk profile for 12 months after completion. The HRU detective sergeant has general responsibility for the management of this data and relevant anonymised data is entered onto master databases.

Hours of operation

The HRU usually operates between 8am to 4pm, Monday to Friday and has a central office at Cheshire Constabulary headquarters.

Referrals and allocations received outside of these hours are assessed on a priority basis. The unit currently does not provide a full service on bank holidays.


An evaluation was led by academics from University College London. This used a multi-method approach to support the EMMIE (effect, mechanism, moderators, implementation and economic cost) evaluation framework. EMMIE assesses whether an initiative works, how, for whom, and under what conditions.

Specifically, this evaluation sought to investigate the following questions.

  • Does the intervention (MASIP) work? Does it achieve its intended aims?
  • How does it work? Through which mechanisms?
  • What is the impact of moderating conditions? This focuses on interventions chosen for particular cases and caseloads.
  • What are the lessons learned from the implementation of the pilot project to guide the setting up of similar partnerships in the future?
  • Is the intervention cost effective?

To answer these questions, quantitative and qualitative data was collected and analysed. Qualitative data consisted of analysis of interviews conducted with perpetrators and victims.

The quantitative data consisted of police force-level data and partnership data. The force-level data from the three local area partnership sites was compared to similar forces, to understand case outcomes with regards to charges and cautions. This was followed by quantitative analysis of partnership data from the three local area partnership sites, which assessed referrals and reoffending statistics.

Key findings

The outcomes for the police force data reflected favourably on the three local area partnership sites. Each of them had a greater proportion of cases that resulted in a charge. Proportionately fewer resulted in a caution in Cheshire and Hampshire forces, which are considered an inappropriate outcome for stalking cases.

However, it is worth noting that the data period for the police force analysis did not cover the full effects of MASIP, and therefore is likely to underestimate the effects that the three local area partnership sites had on positive police outcomes. This is because it takes time for police outcomes (for example, charges) to happen, and the data period finished before MASIP itself concluded.

It was simply too early in the project to conclusively determine if specific health interventions reduced reoffending. The signs from Cheshire and Hampshire indicate that it is promising.

Cheshire had the most developed data collection processes, and the project team is confident they could pick up on most, if not all, reoffending (even if this did not result in a charge or conviction). The rate of reoffending for perpetrators who had completed a health intervention in Cheshire was 17.6%. This is at the lower end of the range reported in research studies where a psychological intervention has been used with stalkers. This suggests that Cheshire’s health interventions were successful.

Hampshire and London did not have formal mechanisms within their partnership data for monitoring and recording reoffending. They were able to extract out qualitative information on reoffending in Hampshire, but believe that this was inconsistently recorded and therefore underestimates the rate of reoffending. Nevertheless, the reoffending rate within six months of the case being monitored in Hampshire was 6.4%, which is lower than similar figures reported in research.

Force level data in London revealed that the reoffending rate relating to the six-month period after their stalking reduction intervention (the Stalking Threat Assessment Centre) began operating (3.2%) is lower than the previous period (4.4%). But this difference is not statistically significant. This analysis likely underestimates the reoffending rate, since there are no unique identifiers on the crime recording system in London for perpetrators or victims, which makes the analysis challenging.

Interviews with stakeholders and perpetrators indicated a high level of satisfaction with the bespoke intervention provided and there was a degree of confidence in the perpetrators that they had the tools necessary to address their obsession and fixation in the future. The small sample size of perpetrators interviewed does however encourage caution about this finding.

Victims were not always satisfied with the sentences given to perpetrators, as they did not think that the sentences were reflective of the gravity of the offence. However, victims were overall satisfied with the support provided to them by the victim advocates. In particular, the victim advocates kept victims informed and empowered them to manage their own safety and support the investigation.

Findings of the cost-benefit ratio indicated that when institutional costs (such as prison and secure hospital) are excluded, there is always a cost-beneficial finding for the state, across all local area partnership sites.

The other notable finding is that MASIP intervention is not always cost-beneficial for victims. This is primarily because the initial experience of victimisation has a high cost for the victim, in terms of the impact on their own mental and physical wellbeing and those of their family and friends. While some of these costs cannot be prevented, MASIP could be considered to prevent those costs escalating into worst-case scenarios. These often involve both continued ill effects of constant stalking and in some cases can have serious or fatal outcomes for the victim. The risk of persistence and risk of escalated violence are both possibilities in the absence of MASIP intervention. Given the high risk associated with some types of stalkers, the cost savings to victims and their families because of intervention by MASIP could be substantial.

Stakeholders perceived that a multi-agency approach did improve the response to stalking as a crime type. This was in terms of better and more efficient investigation and appropriate charging of cases, and that information sharing was extremely useful for risk assessment and risk management in stalking cases.

Stakeholders indicated that victims required further support from victim advocacy, which is resource intensive. There was a need for more mental health provision to help them cope with the aftereffects of being victimised.

Overall impact

The evaluation of the IASU has led to sustained and increased commitment from partners to enhance and broaden the scope and remit of the service (now the HRU) to apply it to an increasingly diverse spectrum of problem behaviours.

Cheshire has the highest charge rate for stalking in the country and performs well in terms of its use and application of stalking protection orders.


  • Data collection and data management needs of interventions such as MASIP require dedicated resources (with the appropriate skills) to monitor progress and manage caseloads. The importance and role of project management in a venture of this nature was highlighted throughout the pilot project.
  • Adequate and sustained resourcing is crucial for the success of this project. People in post must have appropriate skills and motivation to work with victims and perpetrators in a multi-agency environment.
  • Buy-in from key stakeholders is also important.
  • Project stability for three to five years is essential if the effects are to be properly observed.
  • There is limited evidence to suggest the superiority of any one model, since only Cheshire had robust data collection procedures for reoffending. Instead, partnership models should be designed specifically to suit local context and conditions and requirements of the area to be served by these partnerships.
  • At the start of any project, the importance of collecting appropriate data and setting up frameworks cannot be stressed enough. Partnerships require someone with good data management skills and should invest in training to ensure that person can work efficiently and effectively. That person also ideally requires access to both police and health databases.
  • Project management should be a vital role within a partnership, and not just an add-on to operational requirements. Project managers can oversee information sharing agreements, help set up processes and procedures in new units and ensure that requests from funders about impact are managed appropriately.
  • To ensure that service provision is truly inclusive and accessible to all, equality considerations need to be designed into the service from the beginning. This may include working with local third sector organisations to build sensitivity to rarely heard groups.
  • The fact this service is led and developed by practitioners is crucial to its continued success.


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Disclaimer: The views, information or opinions expressed in this shared practice example are the author's own and do not necessarily reflect the official policy or views of the College of Policing or the organisations involved.

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