Electronic Monitoring in Scotland Working Group Report

Report and recommendations on electronic monitoring produced by the expert working group.

Using New Electronic Monitoring Technologies

The Working Group is clear that the technology, in itself, should not dictate how and in which circumstances electronic monitoring should be used. However, the availability of new technology, namely GPS and Trans-dermal Alcohol Monitoring ( TAM), does present increased opportunities to use electronic monitoring in different ways and at different points in the Scottish criminal justice system.

Radio Frequency Technology

Since 2002, Scotland has used radio frequency ( RF) technology as an effective way to monitor an individual's presence at an address, in line with set curfew requirements, or to monitor when an individual enters an "away from" exclusion zone. To date, RF technology has proven to be an effective method of monitoring individuals within the current service although "away from" have not been widely used and are in fact quite a limited way of setting up exclusion zones.

However the principle of confining people with convictions to their own homes was none the less a valid one and the working group sees no reason to dispense with it.

The SCCJR Scottish and International Review of the Uses of Electronic Monitoring, (2015 SCCJR research), carried out by Gill McIvor & Hannah Graham found that:

" GPS may complement radio frequency, but there is not a clear case for GPS to totally replace radio frequency for use with all monitored people."

The European Project; 'Creativity and effectiveness in the use of electronic monitoring as an alternative to imprisonment in EU member states' drew the same conclusion:

"Radio frequency and GPS technologies have complementary advantages and uses"

( [4] Hucklesby et al 2016)

This finding draws on the Council of Europe recommendations for the principles of proportionality and the Working Group therefore recommends that the use of RF technology remains within the Scottish electronic monitoring service.

GPS Technology

GPS technology enables the monitoring of movement over a wide area rather than the monitoring of presence at a single location. It is widely available and used throughout Europe - although nowhere on a large scale - to monitor an individual's compliance with specific requirements set by the Courts, Probation Services or the Prison Service. GPS works, in conjunction with the mobile phone network, to monitor the movements of individuals, rather than their location at a single place.

GPS offers five behavioural possibilities which can be used separately or together:

  • If constant and immediate deterrence is required then real-time tracking, 24/7 is warranted. If less immediate deterrence is required, retrospective tracking (maps of trails provided at a point later) may suffice
  • If keeping a monitored person away from an individual victim, or from an area where he/she frequently offends, exclusion zones may be created, and GPS used to monitor their perimeter
  • An alternative way to restrict a monitored person spatially - and to keep them away from a former victim - is to create an inclusion zone which limits the places to which they can travel or requires that they be at a certain place
  • Hybrid systems which combine retrospective tracking with a switch to real-time tracking if an exclusion zone perimeter (or surrounding buffer zone) is approached or crossed can also be created
  • Intelligence gathering via close observation of monitored people's movements and the discernment of patterns within them. Notably though, the Council of Europe Recommendation, which is discussed later in this section, expressed concerned that this should never become a major feature of GPS monitoring schemes.

The popular image of GPS is of "real-time tracking, 24/7" but this is by no means the only use to which it can be put: other capabilities may be more useful for supervisory purposes.

At the Scottish EM national conference on 26 August 2015, the Cabinet Secretary confirmed Scotland's commitment to introduce GPS technology alongside RF technology. At that time no commitment was made on which groups of individuals GPS technology would be used for, but the Cabinet Secretary tasked the Working Group with preparing recommendations for its usage.

An important conclusion of the 2015 SCCJR research was that GPS technology, if used as a punishment within the Scottish justice system, must be provided for in statute. In addition, significant consideration should be given to the collection, storage and use of data collected as a consequence of GPS monitoring. The Group agrees with these conclusions and in particular extends the requirement for legislation to underpin any use of GPS.

Recognising the versatility of the technology, the Group agreed that the technology should not be restrained to one risk level or one crime type but that public safety and risk to victims should be a factor in determining suitability for EM, the intensity of use and the type of EM used. EM can be used at different levels of intensity it is never the technology which is proportionate to the offence itself but the rigour and duration of the schedules which is used to support and enforce it, and the other interventions with which it may or may not be combined. Low intensity uses of EM can be used with low risk individuals and higher intensity with higher risk individuals, where consideration of victim safety and public protection will be more important. The focus should be on determining how the technology can be best used to achieve the required level of supervision. This could mean real time monitoring with an immediate response from Police Scotland or the Scottish Prison Service, for public protection purposes or the protection of a victim or it could mean using monitoring data retrospectively to assist statutory partners in the management of an individual's behaviour. For example an RLO could be used as an alternative to a fine rather than an alternative to custody.

GPS Technology, Exclusion and Inclusion Zones

In order to consider how the goals of exclusion and inclusion might be helpful in supervision it is important to note that it has been possible to include "away from" conditions in RLOs, in effect creating places from which individuals can be excluded, however, these have never been used widely or systematically. They use the same RF technology as curfews, placing home monitoring units ( HMUs) at the entrances or exits (or simply around) the prohibited spaces which will register an alert if the monitored person comes into proximity of the perimeter. Only small spaces like a shop or school can be zoned in this way. The larger the excluded space the more HMUs would be needed to surround and monitor it and this could become prohibitively expensive.

GPS technology creates new and more efficient ways of creating larger and more intricately shaped exclusion zones, tailored, if necessary, to specific street patterns. Any size is feasible - from a house, to a neighbourhood, to whole city if deemed appropriate (as has been used in Germany). For any given monitored person, more than one exclusion zone is possible. The sizing, number and duration of zones raise interesting questions of proportionality. Internationally, the rationale of such zones has primarily been to create safe spaces for victims of crime, or specifically to protect them, so that they are not likely to encounter, or fear encountering, the person who offended against them. Exclusion zones have also been used to temporarily "seal off" areas with which an individual is familiar and where he/she has frequently committed crimes - or the kinds of area where they are likely to commit them. In the first English GPS pilots in 2004-06 a person who had sexually offended and who was known to approach children in play areas in parks was prohibited from entering all the parks in a northern city (over 200 of them). Three particular parks were "geofenced" (had electronic boundaries placed around them), but the person was deliberately not told which three; he was in fact caught in one of them.

It is possible with GPS technology to create neighbourhood exclusion zones in the vicinity of where individuals themselves live, by restricting access to their homes to one particular set of streets - they are prohibited from entering it from any other direction. This model was used in the English GPS pilots with persistent and prolific offending individuals: the exclusion lasted for three months after a period of imprisonment, but was progressively relaxed on occasional days and weekends in the second and third months if the monitored person complied with all their supervision conditions, not just the exclusion itself but also keeping appointments with a police or probation officer, and submitting to random drug tests. It proved to be a surprisingly successful motivator of compliance.

GPS technology can also be used to create inclusion zones of varied shapes and size (bigger than the home in which curfews are served) - these too can be neighbourhood or whole town-sized. They impose a spatial restriction on an individual, setting up an external perimeter in which, for a specified period of time, they are contained. Inclusion zones are, over and above a restriction of an individual's own movements, another possible way of keeping an individual apart from a victim.

GPS technology can be - and from some standpoints should be - combined with a requirement for an overnight curfew (or shorter period), to ensure that a person wearing a tracker is obliged to return home to charge it. While the public image of GPS tracking is literally one of "anytime-everywhere" monitoring of movement, usually in real time, this may not be the best - and certainly not the only - way to help manage individuals in the community. The federal GPS scheme for released sexual and violent individuals in Germany only uses inclusion and exclusion zones: the moment by moment monitoring of their movements and the recording of their trails is considered disproportionate and not strictly relevant to the safeguarding of former or potential victims (people who may have been threatened by the individual). Information about the person's movements is available to the police for investigatory purposes only by request, and requires judicial approval.

Trans-Dermal Alcohol Monitoring Technology

There are two forms of remote alcohol monitoring; one breathalyser based for use with home confinement the other 'trans-dermal' for use on mobile subjects. The Working Group considered the use of Trans-Dermal Alcohol Monitoring - or sobriety bracelets - and how that technology might be used within the Scottish justice system.

Trans-Dermal Alcohol Monitoring uses ankle bracelets to detect the presence of alcohol when it is sweated out through the skin (trans-dermally). All available evidence suggests that trans-dermal alcohol monitoring requires to be set within a legal framework to be effective; experimental voluntary schemes in Scotland have not been successful, and experience seems to suggest that without a legal framework, and responses to non-compliance, it is too easy to yield to impulse to temptation and give up on the monitoring.

Violence Reduction Unit statistics state that from January to September 2015 Scotland had the following number of offences committed where alcohol had been involved:

Serious violence


Common Assault






This is not to say that alcohol is the unique denominator in the crime - but it was a factor. Any individualised approach to addressing alcohol related offending does not preclude the need for broader cultural factors to be pursued.

The 2015 SCCJR research considered how remote alcohol monitoring was used internationally. The report considered reliability and accuracy compared with other methods, impact in terms of reduced alcohol consumption and desistance from crime, cost effectiveness and how remote alcohol monitoring might benefit the Scottish Justice System.

The research concluded that, as a technology, Trans-dermal Alcohol Monitoring had advantages over other alcohol monitoring technologies as it was:

"less prone to cheating, provides continuous, round the clock monitoring and ….can provide samples regardless of where the monitored person is."

The 2015 SCCJR research also highlighted a number of other advantages including as a deterrent to alcohol consumption during the period of monitoring, enabling individuals to proceed to a recovery stage.

In terms of its use within the Scottish Justice System, the research suggested potential for use as a diversion from prosecution, as a condition of bail, as a condition of a community sentence and as a condition of early release from prison.

The Working Group concluded that there was convincing evidence that the technology was effective and that the possibilities for using remote alcohol monitoring in a Scottish setting should be explored further.

Overall, the Working Group concluded that new and improved technology presents further opportunities to use electronic monitoring in different ways and at different points within the Scottish Criminal Justice System. In considering electronic monitoring technology, the Working Group reviewed the evidence for RF, GPS and TAM technology. The timescales for introducing new technology would be dependent on the timing of changes to Primary legislation.

Recommendation 1: Technology

Radio Frequency is an effective monitoring technology which should continue to be used within the Scottish electronic monitoring service.

GPS technology should be introduced to the electronic monitoring service in Scotland. The Working Group recommends that the use of GPS is not predicated by crime type. GPS technology is versatile and decisions on its use should be made as part of an individually tailored approach, including where it can aid wider public and victim safety and where it can be used supportively to strengthen the monitored person's desistance.

Trans-dermal Alcohol Monitoring technology is effective at remotely detecting the presence of alcohol and its use within a Scottish setting should be explored further. Work should, therefore, be undertaken to determine how alcohol monitoring might be used effectively and at which points within the Scottish Justice System. This work could take the form of a demonstration project.


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