Assessing the effectiveness of Radio Frequency Electronic Monitoring for community and suspended sentences

This research used data made available via the Office for National Statistics (ONS) Secure Research Service, which is being expanded and improved with ADR UK funding.

Author: Professor Ian Brunton-Smith, University of Surrey, Ministry of Justice

Date: January 2026

Research summary

This study evaluated the impact of Radio Frequency Electronic Monitoring (RF EM) on reoffending and compliance among adults serving community and suspended sentence orders in England and Wales. It found that RF EM significantly reduced reoffending during monitoring periods and improved compliance with probation requirements, providing evidence to inform sentencing policy and probation practice. The research has been shared across government and justice agencies, helping to shape discussions on community sentencing and compliance strategies. 

The research was funded by the Evaluation Accelerator Fund in collaboration with the Economic and Social Research Council (ESRC) and supported by the Ministry of Justice’s Data First programme.

Data used

The analysis used linked administrative datasets that can be accessed via the ONS Secure Research Service:

• Probation Service Management Information System (nDelius) – records of community and suspended sentence orders (2014–2018)
• Magistrates’ Court and Crown Court data – court reconvictions (2011–2021)
• Offender Assessment System (OASys) – criminogenic needs and risk scores.

It also used Electronic Monitoring Service Provider data, containing info on RF EM installation and removal dates.

Methods used

The study used a design that compares similar groups of people to understand the effects of RF EM. To do this, researchers applied three different analytical approaches that help make fair comparisons between those who did and did not receive RF EM:

• Propensity Score Matching
• Coarsened Exact Matching
• Causal Machine Learning

Together, these methods helped ensure the groups being compared were as similar as possible. This allowed the study to estimate the impact of RF EM on reoffending and compliance.

The study looked at:

• Whether people were reconvicted while being monitored
• Reconvictions across the full sentence or supervision period
• Reconvictions within 12 months after the sentence ended
• Compliance measures, such as breach rates and completion of probation requirements.

Research findings

RF EM reduced reoffending during monitoring periods:

• Community orders: 17% reconviction vs 22% without RF EM (five percentage point reduction)
• Suspended sentence orders: 15% vs 18% (three percentage point reduction).

Improved compliance:

• Offenders with RF EM were less likely to breach sentence conditions (7% vs 16%) and more likely to complete other requirements (65% vs 54%).

Modest deterrent effect after the sentence ended:

• No clear reduction for community orders, but suspended sentence orders showed a small decrease in reconvictions within 12 months (30% vs 33%).

Impact varied by offence type:

• Greatest reductions observed for theft, robbery, and drug offences.