The national ARMS evaluation

Research Institution / Organisation

Anglia Ruskin University

In Collaboration With

The National Police Chief's Council; Her Majesty's Prisons and Probation Service

Principal Researcher

Dr Natalie Mann

Level of Research

Professional / Work-based

Project Start Date

November 2017

Research Context

There are currently around 52,770 registered sex offenders (RSOs) in England and Wales. Management of Sexual Offender and Violent Offender (MOSOVO) police teams monitor and manage these individuals in the community for the duration of their registration period, something that can vary between two years and life. A vital part of the on-going management of RSOs in the community is effective risk assessment and risk management by Police, coupled with rehabilitative work carried out by the National Probation Service (NPS). In 2014, a new risk assessment tool for use with male RSOs was implemented. The Active Risk Management System, or ARMS for short, provides a national standard for the risk assessment of sexual offenders and risk management planning. ARMS is a structured assessment process to assess dynamic risk factors known to be associated with sexual re-offending, and protective factors known to be associated with reduced offending.

The main aim of the research is to conduct a national evaluation of ARMS in order to understand how police and probation can most effectively use ARMS to manage and monitor RSOs in the community. In order to achieve this, we have designed three complimentary and overlapping work packages which integrate practitioner and academic knowledge using a mixed methods approach. The integration of practitioner and academic knowledge is key in terms of validity and triangulation, but also in terms of ‘ownership’ and the potential impact of outputs. By using a mixed methods approach, we can develop the most comprehensive understanding of the effectiveness of current practice in RSO risk management.

Together the work packages will evaluate ARMS in relation to it’s: 

  • internal reliability, 
  • efficacy as a risk management tool, 
  • impact on decision-making, 
  • applicability across different offender types and cases, 
  • value as a shared assessment tool.

The implementation of ARMS began in 2014, and as such the timing of this evaluation will allow us to draw on three and a half years of quantitative and qualitative data relating to RSOs, their risk assessments and risk management plans. 

This research is being undertaken by A Policing Institute for the Eastern Region (PIER).

Research Methodology

National Service Mapping and Best Practice Agreement

1. Data collection questionnaire to MOSOVO Police leads in all 43 forces and 7 NPS Heads of Public Protection.
2. Telephone interviews with the MOSOVO leads, 14 Senior Probation officers and 14 Probation officers from the 7 NPS divisions, based around mini Delphi-style best practice statements.

Reliability and process effectiveness
1. Inter-Rater Reliability Coding Exercises involving 15 MOSOVO teams and five NPS divisions. Results will be analysed using SPSS, to allow for a comparison between official assigned score, and scores assigned by the practitioners.
2. Process Focus Groups will be held with the same sample and will investigate the participants’ experiences of using ARMS. Data will be thematically analysed using Nvivo.
3. Outcome Effectiveness from outcome data (e.g. risk level, risk management plans, monitoring visit schedule) will be analysed.

Decision-making, Planning and Case Progression
1. Practitioner in-depth Interviews with a sample from five MOSOVO teams and two NPS divisions. The qualitative data will be analysed thematically.
2. Field Observation of sample staff which will produce statistical data on time taken to complete ARMS, as well as thematic data on decision-making, planning and management.

Interim reports and publications

​Not available

Date due for completion

November 2019
Return to Research Map