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Examining implementation of the Stable and Acute dynamic risk assessment tool pilot in England and Wales

Prison stairs
Published: March 2010


The aim of this study was to evaluate the Stable and Acute dynamic risk assessment (S & A) pilot in England and Wales and give recommendations on areas such staff training, implementation and delivery processes for future national roll-out. The research focused specifically on the application of the tool, rather than how well it performed in the pilot.

The Stable and Acute dynamic risk assessment tool

S & A is an assessment tool for police and probation staff to identify the risk factors that suggest a sexual offender may imminently offend. Two complementary assessments are used: Stable (which assesses learned behaviours and personal skills) and Acute (which assesses factors that in the last hours or days are predictive of imminent sexual offending).


We found that police and probation staff valued the use of the tool because they felt it improved their own skills and in turn enhanced risk management practice. In particular they reported the tool enabled:

  • an increased awareness of critical issues
  • a more targeted response to high-risk offenders, such as introducing more home visits
  • improved partnership working based on clearer shared information yielded by the tool

Although the tool showed good promise, the pilot also highlighted important limitations:

  • Models for delivery varied by area.
  • There were concerns about the reliability of the tool. When it was tested by different experts and officers rating the same cases, different results were achieved.
  • Some officers raised concerns that having identified offenders’ needs, routes to address these were not always open to them.

On the basis of the research, we made several recommendations including:

  • robust selection and training of staff
  • continual support for staff once they are fully trained
  • closer integration of police and probation information
  • continuous re-evaluation of the tool it is was rolled out nationally


Mixed methods were used to evaluate the pilot: qualitative research interviews were conducted with 50 operational staff using the S & A in their routine assessments across ten case study areas, quantitative monitoring data collected during the pilot were analysed and an set of inter-rater reliability test exercises, whereby officers involved in the pilot and experts on the S & A assessed a set of anonymised sex offender case files. 

Read the report