Official Statistics

Technical Note

Published 26 May 2022

Introduction

The Electronic Monitoring statistics publication covers the use and delivery of electronic monitoring, that is, location monitoring, alcohol monitoring, and electronic monitoring services’ performance for England and Wales. This document provides more detail on those statistics and is intended to be used as a guide.

Overview of Electronic Monitoring Statistics

Background

Electronic monitoring for compliance with curfews was introduced in 1999 to support the police, courts, prisons and wider justice system in England and Wales. It is a way of remotely monitoring and recording information on an individual’s whereabouts or movements and alcohol consumption, using an electronic tag which is normally fitted to a subject’s ankle. Information about the compliance with an individual’s order is monitored. Electronic monitoring may be used:

• as a condition of court bail;

• as a requirement of a court sentence, primarily community orders and suspended sentences;

• for Home Detention Curfew

• as a licence condition following release from custody;

• as a condition of immigration bail, managed by the Home Office; and

• to intensively monitor a small number of individuals including: some of the highest risk offenders managed under Multi-Agency Public Protection Arrangements (MAPPA); those granted bail by the Special Immigration Appeals Commission (SIAC); and those made subject to Terrorism Prevention and Investigation Measures (TPIMs).

The service to monitor curfews was expanded from November 2018 to introduce satellite enabled (GPS) location monitoring. GPS tags are now available to sentencers and decision makers as an option for court and post-custody cohorts. This is in addition to the use of GPS tags to monitor a small number of specialist cases. The tags use GPS technology to record an individual’s movements 24 hours a day. Roll-out was fully completed in March 2021 with the provision of location monitoring for under 18s.

GPS tags provide additional functionality, allowing the monitoring of:

• Compliance with exclusion zones.

• Attendance at a required activity or appointment.

• An offender’s whereabouts, known as trail monitoring. This can provide offender managers with data about an individual’s whereabouts to support rehabilitative conversations. (This is not available for court bail and the Police Courts and Sentencing Act 2022 introduces this for Youth Rehabilitation Orders.)

• Multiple conditions or requirements if necessary, such as a combination of exclusion zones, curfew, monitored attendance and trail monitoring.

More recently HMPPS has expanded use of GPS tags to two offender cohorts:

• Acquisitive crime: From April 2021 they have been used as a licence condition for adult offenders convicted of acquisition crime and who have served a prison sentence of 12 months or more. This is currently being piloted in 19 police forces.

• Foreign National Offenders (FNOs): The Immigration Act 2016 introduced a duty on the Home Office Secretary of State to impose an electronic monitoring condition on FNOs granted immigration bail pending deportation. Following this, in August 2021, HMPPS began using GPS monitoring for these individuals who have been released from Prisons or Immigration Detention under ‘Immigration Bail’ on behalf of the Home Office.

Alcohol monitoring was introduced in October 2020 and went live throughout England and Wales on 31 March 2021 to support the new community sentencing option, the Alcohol Abstinence and Monitoring Requirement (AAMR). An AAMR may only be used when sentencing for alcohol-related criminal behaviour and it imposes a total ban on drinking alcohol for up to 120 days. Compliance with the ban is monitored electronically using an alcohol tag which continuously monitors for the presence of alcohol.

It may be imposed by the court as part of a Community Order or Suspended Sentence Order where:

• The offence, or associated offence, for which the requirement is being imposed, is alcohol-related;

• The subject is not alcohol dependent or has an Alcohol Treatment Requirement (ATR) recommended or in place; and

• The subject is an adult i.e. 18 years or over

For offenders being released from custody whose offending and risk is alcohol related, an Alcohol Monitoring on Licence (AML) licence condition was introduced in Wales in November 2021 and will be rolled out to England in June 2022. There are two conditions available for AML:

• Requires total abstinence from alcohol, or

• Requires the offender to comply with requirements specified by their supervising officer to address their alcohol needs, this will include limiting alcohol use.

Data Sources and Methodology

The data in this release are compiled from are Electronic Monitoring Services (EMS) contractor data and Alcohol Monitoring Services (AMS) contractor data, which in turn is derived from their case management systems. Caseload and basic demographic information about tagged individuals, as covered in this release, is considered to be of good quality as these are data required to actively manage a case. However the statistics may differ from other statistics on electronic monitoring requirements provided by other data sources (such as those presented within the Offender Management Statistics Quarterly publications which are based on data held by the Probation Service).

This release contains data about:

• Monitored electronic monitoring individuals
  A monitored subject is defined as an individual with a tag fitted and, in the case of radio frequency tags, a Home Monitoring Unit (HMU) installed . An individual may be subject to multiple orders at the same time: in this instance the individual is recorded under the order with the latest order end date.

• New order notifications
  This is a count of all new order notifications, regardless of whether a tag is fitted or whether an individual is already covered by another order.

• Completed order notifications
  This is a count of all completed orders, regardless of whether a tag was fitted or whether an individual is still covered by another order.

There are a number of individuals who, according to the case management systems, are covered by a live order but do not have a tag fitted. This could be for several reasons, such as the tag not yet having been fitted. However, it can also arise from communication issues, such as the correct authority having not been informed when an individual has been recalled to prison or consent for the tag fitting has been withdrawn.

Caseload details are received from the contractors at a regular frequency throughout the year. We conduct a range of quality assurance checks on these to identify any errors or inconsistencies in the data. We also conduct an annual reconciliation process to ensure any errors in previous returns have been corrected and to ensure any late order notifications, which may have been missed from the original extracts, are included. AMS data was out of scope for this data conciliation process, as was the breakdowns of the GPS cohorts. As a result of this activity data quality concerns with the April 21- March 22 data have been identified and adjusted as follows:

Immigration bail: In August 2021 there was a change to the policy for those subject to immigration bail orders, which increased the numbers eligible for EM. Consequently an increase was seen in the number of immigration bail new start order notifications. However, a system error in the recording of these individuals showed most of these new immigration bail orders did not have a tag fitted which was inaccurate. Working with the Home Office and EMS we have used data about active GPS tags (those which have had activity logged within the last 7 days) to identify individuals with both a live immigration bail case order and an active tag. This adjustment is a fairly manual process and we plan to use reproducible analytical pipeline principles to automate this, which may lead to future revisions.

Alcohol monitoring: Due to an error in the case management system there is an over recording of the number of individuals with an active alcohol monitoring tag fitted. We account for this by using the live SCRAM system to identify the active tags and matching this to the caseload data.

Dual tagged: Although managed by the same contractor, alcohol tags are managed through a separate case management system. Some individuals are subject to both alcohol monitoring and electronic monitoring (RF or GPS) and so summing the number of individuals from both systems would be an over-estimate of the number of the number of individuals subject to electronic monitoring. AMS does record whether an individual is subject to an EMS order when a new order notification is received, but this does not provide an accurate count of the number of individuals subject to both tag types on any specific date. To estimate the number covered by both EMS and AMS we link those that have a dual tag indicator on AMS and using the EMS reference (where populated), or the name and date of birth, to EMS. Where this join produces a match, and both the EMS and AMS record is a) live at that date, and b) has a tag fitted, the individual is considered as being dual tagged.

Performance measures: While the performance measures are also calculated using data provided by EMS, the data undergoes a separate assurance exercise to ensure that cases that do not meet the requirements, or cases excluded from the calculation (where failing to meet the requirement is outside of the contractor’s control) are checked along with a sample of those that met the requirements. This verification work ensures the contractual requirements that drive supplier payment are met. Consequently the figures presented in the performance tables reflect the performance of the contractor, rather than the performance of the whole electronic monitoring system. To note the figures presented are from EMS and exclude alcohol monitoring. Further details about the service levels can be found in the annex.

Data Limitations

This publication has been produced to the high professional standards as set out in the Code of Practice for Statistics. However, the analysis is only as good as the data upon which it is based, and there is inherent uncertainty when the data is derived from diverse administrative data systems. Furthermore there are gaps in the evidence base that the administrative system cannot be expected to fill.

Within the Department we are seeking to address this through:

• Developing a measure of compliance (with the non-alcohol tags)

• Undertaking a feasibility study to link data from EMS to other data sources held centrally, such as nDelius

• Undertaking a discovery exercise to see what we can find through other data sources held centrally with regards the demographics and protected characteristics of individuals with tags

Symbols and Conventions

The following symbols have been used throughout this publication.

Symbol	Description
0	nil
-	not available
..	suppressed
r	revision
p	provisional

Notes

Confidentiality

This statement sets out the arrangements in place for protecting persons’ confidential data when statistics are published or otherwise released into the public domain. The Code of Practice for Statistics states that:

“Organisations should look after people’s information securely and manage data in ways that are consistent with relevant legislation and serve the public good”. (Trustworthiness pillar, T6 Data governance)

To comply with this and with the Data Protection Act of 1998, and to maintain the trust and co-operation of those who use reoffending statistics, the following provisions have been put in place.

Private information collected by the Ministry of Justice is stored in line with Ministry of Justice data security policies. Electronic data are held on password-protected networks. All new staff undergo Ministry of Justice security vetting before receiving access to data systems, and all staff undertake mandatory training on information responsibility annually.

Three types of disclosure risk are considered in relation to reoffending statistics: general attribution, identification (including self-identification) and residual through combination of sources. Assessment of the risk of disclosure considers the following:

• Level of aggregation (including geographic level) of the data

• Size of the population

• Likelihood of an attempt to identify

• Consequences of disclosure

As a result, the number of monitored subject counts of 2 or fewer are suppressed. This is to prevent the disclosure of individual information.

Timeframes and Publishing Frequency of Data

This publication is new for 2022 and brings together statistics previously published in the Community Performance Publication, HMPPS Digest Publication, HMPPS Equalities Publication and Alcohol Monitoring Publication into one Electronic Monitoring Publication. The statistics in this publication are for the previous 12 months and are planned to be published quarterly.

Revisions

In accordance with Principle 2 of the Code of Practice for Statistics, the Ministry of Justice is required to publish transparent guidance on its policy for revisions. A copy of this statement can be found here.

The three reasons specified for statistics needing to be revised are changes in sources of administrative systems or methodology changes, receipt of subsequent information, and errors in statistical systems and processes. Each of these points, and its specific relevance to the Electronic Monitoring publication, are addressed below:

1. Changes in sources of administrative systems/methodology
The data within this publication comes from a variety of administrative systems. This technical document will clearly present where there have been revisions to data accountable to switches in methodology or administrative systems. In addition, statistics affected within the publication will be appropriately footnoted.

2. Receipt of subsequent information
The nature of any administrative system is that data may be received late. For the purpose of this criminal justice statistics publication, the late data will be reviewed on an annual basis but, unless it is deemed to make significant changes to the statistics released; revisions will only be made as part of the final release containing the calendar year statistics. However, should the review show that the late data has major impact on the statistics then revisions will be released as part of the subsequent publication.

3. Errors in statistical systems and processes
Occasionally errors can occur in statistical processes; procedures are constantly reviewed to minimise this risk. Should a significant error be found, the publication on the website will be updated and an errata slip published documenting the revision.

Contact details

For enquiries, comments or further information, please contact:

Julie Sullivan
HMPPS Electronic Monitoring Performance
Data and Analysis
Ministry of Justice
7th Floor
102 Petty France
London
SW1H 9AJ

Email: statistics.enquiries@justice.gov.uk

Alternative formats are available on request from statistics.enquiries@justice.gov.uk

Annex A: Glossary of terms

Acquisitive Crimes	Theft, robbery or burglary
Alcohol Monitoring	A way of remotely monitoring and recording information on an individuals alcohol consumption, using an electronic tag
Court Bail Order	When an individual is awaiting a court hearing or trial and are released from custody until the hearing or trial but must be monitored with an electronic tag
Court Sentence	When community orders or suspended sentence orders are imposed on an individual by the court requiring monitoring with an electronic tag
Electronic Monitoring	A way of remotely monitoring and recording information on an individual’s whereabouts or movements, using an electronic tag
Electronic Monitoring Services (EMS)	The organisation responsible for the delivery of Electronic Monitoring
Foreign National Offenders	Offenders who are not UK citizens
Licence	The period in which a prisoner is released from prison to serve the remainder of their sentence in the community
Location Monitoring	Satellite enabled (GPS) electronic tags
Immigration Order	Foreign National Offenders released from Prisons or Immigration Detention under ‘Immigration Bail’ but must be monitored by an electronic tag while awaiting deportation
Post Release Order	When an individual has been released from prison on the condition that they are monitored with an electronic tag
Specials	Highest risk offenders managed under Multi-Agency Public Protection Arrangements (MAPPA); those granted bail by the Special Immigration Appeals Commission (SIAC); and those made subject to Terrorism Prevention and Investigation Measures (TPIMs)

Annex B: Electronic Monitoring Timeline

Overview of Electronic Monitoring policy changes

Date	Summary
Nov 2018	National rollout of GPS tags
Oct 2020	Alcohol monitoring tags launched
Apr 2021	Acquisitive crime cohort launched
Aug 2021	Immigration cohort expanded to foreign national offenders
Sep 2021	Acquisitive crime cohort expanded
Nov 2021	Alcohol monitoring for prison leavers launched

Annex C: Service Level Agreement Details – all to be attempted within the specified timescales

EM Service Level Measure 4A: Equipment Installation and Subject induction – First attempt

The Electronic Monitoring service provider will receive a notification of a new monitoring requirement. Where the information supplied in the request is complete there is a requirement that the EMS provider makes a first installation attempt within defined timescales of receipt, as follows:

i) The first day of monitoring requirement where the curfew is a Daytime Curfew and is received 4 or more hours before the end of the curfew period.

ii) the first day of monitoring requirement where the curfew is an Overnight Curfew, or a Split curfew and the notification is received before 15:00 of that day and the curfew start time is before 23:00 for adult subjects and before 21:00 for juvenile subjects.

iii) the second day of monitoring requirement where the curfew is Overnight Curfew, or a Split curfew and notification is received after 15:00 on the first day of monitoring requirement or the curfew start time is before 23:00 for adult subjects and 21:00 for juvenile subjects.

iv) the deadline times for installation are 23:59:59 for adult subjects and 22:00 for juvenile subjects, except where the curfew start time is at or after 23:00 (or after 21:00 for juvenile subjects) the deadline time is the earlier of two hours after the curfew start time or 01:00 the next day.

This measure provides assurance that the provider has made the necessary steps to initiate the electronic monitoring of the subject. The timeliness element of the measure is to incentivise good public protection practice and compliance with sentence delivery.

EM Service Level Measure 4B: Equipment Installation and Subject induction – Further attempt(s) within specified timescales

The Electronic Monitoring service provider will receive a notification of a new monitoring requirement. Where the information supplied in the request is complete there is a requirement that the EMS provider makes a first installation attempt within defined timescales of receipt. Where a first attempt to install monitoring, equipment is unsuccessful the provider should make a second (and for juvenile subjects, where required, a third) attempt to install monitoring equipment, each attempt being made within defined timescales, as follows:

i) The second day of monitoring requirement for the second attempt (and the third day of monitoring requirement for the third attempt for juveniles only) for Overnight Curfews, Daytime Curfews and Split Curfews.

ii) the deadline times for installation are 23:59:59 for adult subjects and 22:00 for juvenile subjects, except where the curfew start time is after 23:00 for adult subjects the deadline time is the earlier of two hours after the curfew start time or 01:00 the next day.

This measure provides assurance that the provider has made the necessary steps to initiate the electronic monitoring of the subject. The timeliness element of the measure is to incentivise good public protection practice and compliance with sentence delivery.

EM Service Level Measure 4C: Equipment re-installation

The Electronic Monitoring service provider will receive a notification to re-install monitoring equipment following an address variation or authorised absence. Where the information supplied in the request is complete there is a requirement for the EM provider to make up to two attempts (3 for juveniles) to re-install the monitoring equipment, each attempt being made within defined timescales, as follows:

i) On the first day of monitoring where the notification is received before 15:00 of that day and the curfew start time is before 23:00 for adult subjects and before 21:00 for juvenile subjects.

ii) on the second day of monitoring requirement where notification is received after 15:00 on the first day of monitoring requirement or the curfew start time is before 23:00 for adult subjects and 21:00 for juvenile.

iii) the deadline times for installation are 23:59:59 for adult subjects and 22:00 for juvenile subjects, except where the curfew start time is after 23:00 (or 21:00 for juvenile subjects) in which case the deadline time is the earlier of two hours after the curfew start time or 01:00.

This measure provides assurance that the provider has made the necessary steps to continue the electronic monitoring of the subject. The timeliness element of the measure is to incentivise good public protection practice and compliance with sentence delivery.

EM Service Level Measure 5A: Visit for removal of equipment

The EMS service provider should make a first attempt to remove the monitoring equipment within defined timescales as follows:

i) By 23:59hrs on the day that the monitoring requirement ends for a Subject. If the monitoring requirement ends at AM (e.g. 07:00) on the last day then a decom visit must be made on the previous day between the start of curfew and 23:59.

ii) This measure does not apply to cases where the subject withdraws consent for monitoring. In some cases, there is a valid reason for a notification record not to be considered when calculating service level performance. These reasons are referred to as service level exceptions (SLEs).

This measure ensures that monitoring is ceased at the correct time and that publicly owned equipment is recovered.

EM Service Level Measure 5B: Visit for removal of equipment (bail cases)

The EMS service provider should make a first attempt to remove monitoring equipment for bail cases within defined timescales on the day that the monitoring requirement ends.

I) If bail end paperwork is received before 3pm then a visit must be made by 23:59 on the day that the monitoring requirement ends for adult and juvenile Subjects.

ii) If bail end paperwork is received after 3pm then a visit must be made by 23:59 the following day for adult and juvenile Subjects.

This measure ensures that monitoring is ceased at the correct time and that publicly owned equipment is recovered.

EM Service Level Measure 5C: Visit for removal of equipment (Tampers)

The Electronic Monitoring service provider will receive an alert when a subject has tampered with their equipment. On receipt of this alert the EMS service provider shall visit the subject’s address within specified timescales, as listed below, to check the equipment. The timescales are:

i) Within 4 hours from the time of the alert, if the incident occurs within a curfew period and there are 4 or more hours remaining within the current period.

ii) Within the first hour of the next curfew period, if the incident occurs within a curfew period and there are fewer than 4 hours remaining period and there are more than 3 hours remaining in the period.

iii) Within 4 hours less the time available within the current period, if the incident occurs within a curfew period and there are fewer than 3 hours remaining in the current curfew period.

iv) Within the first 4 hours of the next curfew period, if the incident occurs outside of a curfew period and the next curfew period is 4 or more hours in length.

v) If the incident occurs outside of a curfew period and the next curfew period is fewer than 4 hours in length, the deadline is calculated by rolling through subsequent curfew periods until 4 hours has expired.

This measure provides assurance that the provider collects evidence of tamper violations for the NPS to use in breach proceedings and ensures a Subject has working equipment which allows them to be electronically monitored. This measure provides assurance that all subjects have working equipment. The timeliness element is to incentivise good public protection practice and compliance with sentence delivery.

EM Service Level Measure 7B: Requesting information required to commence orders

The Electronic Monitoring service provider will receive a notification of a new monitoring requirement or requirement to reinstall monitoring equipment. On receipt of a notification the Service Provider shall check the notification for incomplete information. Where information relating to one of eighteen specific categories is found to be incomplete, the Service Provider will request the missing data, within defined timescales, as follows:

i) within two hours of the notification being received if it is received before 15:00 on a working day,

ii) by 10:00 of the next working day where the notification is received on a non-working day or at or after 15:00 on a working day.

iii) by 10.00 the next working day when it is discovered by the FMO, on attempting a visit, that the address cannot be reasonably located.

This measure provides assurance that the provider has made the necessary steps to initiate the electronic monitoring of the subject. The timeliness element of the measure is to incentivise good public protection practice and compliance with sentence delivery.

EM Service Level Measure 8: Contact Curfew Location in the Event a Violation Exceeding 5 Minutes

The Electronic Monitoring service provider will receive an alert that a subject has violated their curfew requirement. On receipt of this alert the Service Provider shall call the curfew location within 30 minutes or less (or 35 where the incident time and process time are the same).

This measure ensures that the provider collects information on the whereabouts of the subject and any information which may be used by the NPS as evidence in breach proceedings. Appropriate investigation of alerts can also indicate equipment faults. Such investigation can incentivise good public protection practice and compliance with sentence delivery.