Offender management – high harm unit (HHU)

The high harm unit (HHU) aims to address the long-standing challenge in offender management: how to identify, assess, and reduce harm. Offenders responsible for offences such as domestic abuse (DA), stalking and sexually harmful behaviours may not have been convicted or subject to multi-agency public protection arrangements (MAPPA).

The overarching aim is to move beyond the traditional offender management models and develop a more preventative and trauma-informed approach. This involves incorporating multi-agency intelligence, structured professional judgement, and both voluntary and enforcement-based interventions to safeguard victims.

The intended outcomes of the HHU are to:

• improve the identification of individuals who pose significant harm, regardless of conviction status
• enhance the evidence-informed process for assessment and risk management
• reduce the likelihood of reoffending among high-risk perpetrators
• strengthen victim safeguarding through proactive use of civil orders and disclosure schemes
• improve inter-agency collaboration and support pathways
• build a replicable model of high-harm offender management for wider national adoption

Dorset Police launched the HHU in June 2023 to identify and manage those responsible for the most harmful behaviours, particularly in relation to violence against women and girls (VAWG). Unlike conventional integrated offender management (IOM) units, the HHU does not restrict its scope to convicted offenders. The HHU includes repeat perpetrators who may not have been charged or prosecuted but whose behaviours, when viewed holistically, indicate a serious risk of harm.

The HHU is supported by a dedicated offender manager and embedded within a wider multi-agency framework. Cases are identified through sources such as the multi-agency risk assessment conference (MARAC) and high-risk domestic abuse (HRDA).

Perpetrators are referred to the HHU through a triage process designed to filter the most urgent and serious cases. Once a referral is made, a triage meeting is held to determine suitability for formal management by the HHU. The triage process includes a detailed discussion of the individual’s:

• behaviour
• known victims
• patterns of escalation
• risk indicators

Structured risk tools such as the recency, frequency, gravity, victim (RFGV) matrix are used where appropriate alongside professional judgement to assess the need for intervention. Individuals who appear low-risk may still be selected for the HHU because of contextual indicators, such as stalking behaviours or controlling coercive behaviours, which are not captured in conventional scoring tools.

High harm perpetrator panels (HHPPs) are then held on a monthly basis to review cases, share intelligence and design bespoke management plans. The HHPPs include representation from:

• Dorset Police
• Dorset Probation Service
• NHS
• Dorset Council local housing
• substance misuse team
• victim advocacy service

Perpetrators are offered support, such as access to the Up2U behaviour change programme, or practical assistance with housing or benefits. Where appropriate, civil enforcement mechanisms are deployed, including Clare’s Law disclosures and protection orders.

The management of each case involves the continuous engagement from both the perpetrator and potential victims. Officers work closely with the individual to promote engagement, often visiting them at home, attending appointments, and supporting them through treatment or court processes. Where individuals disengage or pose a heightened risk, the HHU applies protective sanctions, including domestic violence protection notices and orders (DVPNs/DVPOs) or referrals for prosecution.

Offender manager

The role of the offender manager is complex and requires balancing supportive and safeguarding functions. Officers must engage with perpetrators to foster change, while also monitoring for signs of escalation and protecting victims where necessary. The success of this approach relies heavily on the skills, discretion, and commitment of those in post, alongside strong support from partner agencies.

The University of Suffolk and Bournemouth University evaluated the HHU between 2024 and 2025. 

The evaluation included interviews with officers, observation of triage and HHPP meetings, and reviews of relevant documentation and offender data. 

The findings showed a promising impact. Among a sample of eight perpetrators tracked for the evaluation:

• six (75%) reduced their offending within the evaluation period
• three (38%) committed no further offences

In total, the number of known offences dropped by 55% (from 56 to 25 known offences) from the previous year.

The researchers also noted the significance of non-criminal justice outcomes, such as improvements in housing stability, mental health treatment, and reductions in substance misuse. Every viable case included support for housing and benefits, while the majority of relevant individuals also received substance misuse (82%) and mental health (67%) interventions. Civil safeguarding measures such as Clare’s Law disclosures were issued in 100% of applicable cases, with civil protection orders used in 83% of the cohort.

The evaluation found that assessment and triage processes were highly detailed and grounded in both formal tools and practitioner expertise. However, reliance on professional judgement alone was seen as a potential vulnerability, particularly in high-pressure, resource-constrained environments. The evaluation recommended the development of a bespoke risk assessment tool to support more consistent and evidence-based decision-making.

• The HHU has had a positive impact on efforts to reduce serious harm within Dorset. It has provided a focused, preventative approach to offender management and filled a critical gap in dealing with high-risk individuals outside of MAPPA or conviction-based systems.
• Since the evaluation, the force has improved staff and capacity, with the maximum number of offenders managed increasing from ten to fifteen. There are ongoing discussions with partners, including Up2U and the voluntary sector, to expand the availability of bespoke interventions, particularly for stalking and cases involving sexually harmful behaviours.
• The HHU’s practice model is now being shared with other forces, with potential for wider replication nationally.

• Adopt a triage model early to manage demand and ensure resources are focused on the most high-risk individuals.

• Co-locate offender management and safeguarding roles where possible to ensure seamless integration between enforcement and support.
• Develop bespoke decision-making tools that combine structured risk assessments with local knowledge, rather than relying on generic tools that may miss contextual nuance.
• Secure long-term funding and partnership agreements to support continuity of intervention and monitoring.
• Create a community of practice for units working with non-convicted or high-harm offenders to share training, tools, and outcomes.