Electronic monitoring: uses, challenges and successes

EM and domestic abuse

The final section examines the use of electronic monitoring in relation to domestic abuse perpetrators. In cases of domestic abuse, the purpose of EM is different to that in cases of non-domestic crime. Bilateral Electronic Monitoring (BEM) monitors both an offender’s compliance with the conditions of sentence and protects victims of domestic abuse by monitoring the offender’s movements in relation to the victim. 

In relation to domestic abuse, the primary purposes of using EM are: 

• To reinforce and ensure compliance with protective orders^[296] 
• To record evidence of breaches of no contact orders;^[297]
• To enhance supervision of offenders;^[298] and
• To improve victim safety.^[299]

EM can be used for those with a domestic abuse conviction in Scotland provided they are not excluded from consideration due to their offending history or following risk assessment, however Bilateral EM is not part of the current service in Scotland.^[300]  

Unilateral and Bilateral Electronic Monitoring (BEM) 

Radio Frequency (RF) monitoring is the only type of EM currently used in Scotland.  The RF system is used for the monitoring of people convicted of a domestic crime or offence in Scotland, and the same system is used in other jurisdictions for this purpose.^[301] A 2013 Scottish Government Report further concluded that, both technically and legally, bilateral EM would be possible in Scotland with the combined use of GPS monitoring devices alongside the existing RF system.

In the majority of cases in Scotland EM is used as a unilateral measure,^[302] primarily focussing on the monitored person’s compliance with the conditions of their sentence.^[303]  Offenders may be restricted to a place, from a place, or both to and from places under the conditions of EM.

Bilateral Electronic Monitoring (BEM), which is currently used in the USA, Spain and Portugal, is generally used to enforce protective orders and establish ‘exclusion zones’ around the victim’s home. If an offender enters the exclusion zone, the EM system can give advance warning of the breach to the victim and monitoring authorities.^[304] 

BEM combines the use of RF and GPS technologies. As in cases of unilateral EM, the offender wears a tamper-proof transmitter, usually around their ankle. Bilateral approaches involve a receiver being placed within both the offender and the victim’s home.  The receiver in the offender’s home detects and confirms the presence of the offender within the address during the permitted curfew hours. The receiver in the victim’s house detects the presence of the offender’s transmitter when it is within a defined geographical radius of the house (radii distances cited in studies from the US varied from 500 feet to 2 miles). 

The victim may also be provided with a pager device, which allows the monitoring centre to alert them of the offender’s proximity, and a field-monitoring device that alerts them to the offender’s proximity to the house when they are away from the area.^[305]  Victims can also be given monitoring devices, to carry on their person, or to be tagged in the same way as an offender via a transmitter round their ankle.^[306]  GPS EM is then used to track the victim’s movements and can report breaches by the offender in real time.^[307]

Victim experience

Considering evidence on the experience of victims is particularly salient when evaluating the monitoring of domestic perpetrators. Domestic abuse, by its nature, is a hidden crime. 88% of incidents of domestic abuse take place in the home^[308] and in many cases it is difficult to establish sufficient corroborative evidence. Quantitative evidence on reoffending and reconviction may not provide an accurate picture of the reality of offending and is likely to underestimate the prevalence of domestic abuse. It is unclear what lessons can be learned from considering quantitative outcomes on reconviction rates for perpetrators on EM and other qualitative evaluation outcomes should also be considered.

Evidence suggests the use of EM is victim-centric and improves victim engagement with the justice system. In addition, evidence of breaches are more easily evidenced by EM technologies and victims may feel more supported to report. These factors may result in an increase of reoffending and reconviction in cases of EM for perpetrators of domestic abuse. In terms of measuring the efficacy of EM in domestic abuse cases, analysis of reoffending and reconviction statistics may not provide a clear picture of the reality of offending. It is therefore important to consider the experience of victims, as this provides additional evidence on EM and its impact. 

There is some consistent and robust evidence on the impact of EM on victims. Several publications found that victims and EM practitioners were positive about EM. Evidence from the US suggests that one of the main strengths of EM in cases of domestic abuse is that it is victim-centric, improves the victim’s perceptions of safety and allows them to feel better-informed and better-engaged with the justice system. The following section summarises the key findings of this body of evidence. 

Research on BEM in cases of domestic abuse suggests its use can improve victim safety, empowerment and provide space to reassess the relationship and their future circumstances

Evidence from research interviews in the USA found that victims felt BEM granted them the space required to safety plan, reassess their relationship and their options for the future.^[309]  In a number of US states, EM is used as a mechanism to enforce protection orders. Exclusion zones are established to mirror the zones within the protective order. A national survey of practitioners from the USA provided that 75% of criminal justice professionals working with EM methods felt that victims were empowered by EM systems^[310] and victims interviewed in Erez and colleagues’ (2012) comprehensive USA study also reported improved feelings of empowerment. 

Victims interviewed in Erez et al.’s research also showed that, prior to the use of EM, the perpetrator was able to continue his abuse of them more or less undetected and with impunity.^[311] Once the perpetrator was subject to EM, victims reported feelings of increased safety and freedom and a reduction in levels of harassment and stalking. 

There are also anecdotal examples that suggest BEM can improve victim safety. In Florida, an exclusion zone was established around a victim’s home address. The perpetrator in this case approached the address, allegedly to retrieve his belongings. The victim was alerted of his approach by the monitoring system in advance and had time to lock the doors and windows and turn off all lights and the television. The perpetrator tried to force entry to the house via several windows and the front door, and was then arrested by police who were also alerted to the breach.^[312] While this incident was a recognised breach, without the EM system the perpetrator would likely have gained entry to the property and perpetrated further abuse on the victim.^[313] 

EM can improve victims’ engagement with the justice system  

A 2007 study by Erez and Ibarra^[314] interviewed 30 victims and 22 justice professionals who worked with victims in two Midwest jurisdictions of the USA. The article offers useful insights into the perspective of the victim, with a number of excerpts from victim interviews included as primary sources of data. The article concludes that the use of EM in domestic abuse cases is victim-centric: it can restore victims’ faith in the justice system; make victims more visible within the judicial decision-making process;  improve their engagement with justice professionals; and allow them respite from fear and harassment. 

Other research notes that, at court, domestic abuse cases have higher levels of dismissals than other crime types due to the unique dynamics of domestic abuse and associated pressures on the victim.^[315] Empirical research from the USA evidenced increased levels of victim attendance at court and a decreased likelihood of dismissal for cases that were continued over longer periods of time (as compared to cases where the perpetrator was released on bail without EM).^[316]

Research from the US found victims in domestic abuse cases are often not provided information regarding a perpetrator’s sentence, imprisonment and date of release, and/or the conditions of their bail.^[317]  BEM had the effect of making women more ‘visible’ by including the victim’s perspective in judicial decision-making, and providing victims with more information on the perpetrator’s sentence.^[318]

Guidance and education on EM’s capacity and limitations was lacking in some cases 

Gur and colleagues^[319] reported that, of the 616 EM practitioners surveyed: “fewer than 20% require victims to sign a form acknowledging the capabilities and limitations of the GPS program, one in eight (roughly 12%) provide victims with any training, and one in nine (roughly 11%) require “victim participation” for the defendant to be placed in the GPS monitoring program.” 

BEM has a victim-centric emphasis

Research interviews of 30 victims and 42 criminal justice/victim support professionals across two years in two courts in the USA found that BEM had the potential to mitigate victims’ feelings of fear. BEM mitigated victims’ fear of the perpetrator contacting them directly or through other means such as letters, telephone calls or breaking and entering their home.^[320]  A victim interviewed in one publication provided that:

“I always felt like he was just gonna come out of nowhere and cut my throat or shoot me. Before he was put on (BEM), I went down to 96 pounds from my pancreas and my ulcers. I couldn’t eat from nerves worrying if he was going to break into my home, (or) where he's going to show up. He would stalk me, he would drive down (to) my home, he would show up in places—if I would go out he would show”.^[321]

The knowledge that a perpetrator’s movements were being tracked in real time increased victims’ perception of safety. 

However, some victims did not feel EM of the perpetrator reduced their risk. 

Some victims interviewed in Erez et al.’s (2012) US study felt that pre-trial use of EM for the perpetrator would mean he was “even more crazy and ^{[likely to]} retaliate”.^[322]  A number of victims believed the perpetrator would have the capacity to somehow deceive the technology and be able to continue the abuse. Some victims interviewed in  research by Erez and colleagues were unsure of the extent of their protection and thus ‘tested’ the equipment by activating alerts to authorities to assess the speed and quality of police response.^[323]  

One case included in qualitative research from Spain found that repeated alerts by the monitoring system could cause distress to victims.^[324]  An exclusion zone was set for 500 metres around the victim’s home address but the perpetrator required to go within 400 metres of the address to attend his work. The repeated alerts of the system caused the victim such distress that she withdrew from the programme. The judge in this case was able to modify the exclusion zone to resolve the issue.^[325]

Perpetrator experience

There is also a limited body of qualitative evidence examining perpetrator and practitioner experience of EM in cases of domestic abuse. 

The way in which a monitoring system is operationalised and its objective aims influence how perpetrators and practitioners experience EM. 

Erez and colleagues noted that “an agency’s overarching philosophy of supervision and sense of mission, rather than the technology employed, set the tone and direction that casework takes, shaping how officers practice surveillance”.^[326]

Research from the US found that the way in which monitoring systems are managed can have a significant effect on perpetrator experience.^[327]  The 2014 study conducted interviews with 50 criminal justice practitioners across three separate jurisdictions over three years. The approaches to monitoring varied between a collaborative, transparent approach based on treatment and rehabilitation, to another area where EM was intended to control risk based on surveillance and enforcement. In the former, practitioners wanted to “create a relationship of trust” with the clients and support them to make positive life choices.^[328] In the latter, perpetrators were not provided information regarding the capabilities of the GPS EM system, an intentional strategy designed to “keep defendants in the dark” and “weed out” those who were non-compliant.^[329]

Perpetrator experience of EM can be both positive and negative. 

One practitioner interviewed in the above study perceived that – because perpetrators are obliged to pay for their monitoring equipment in the US – compliance was higher.^[330]  The cost of a unit varied between $10 and $16 per day and the practitioner felt that due to the daily cost, perpetrators tended to pay more attention to their conditions.^[331]

Being subject to a home detention curfew (HDC) and no contact order with the victim means many perpetrators are forced to reside with their parents. Research from the US interviewed 27 convicted perpetrators of domestic abuse, and found that residing with parents was emasculating and infantilising for them and it was difficult to maintain a ‘normal’ social life.^[332] 

A report by Erez and colleagues (2012) identified some benefits for perpetrators of domestic abuse subject to EM, as “providing added structure to their lives, and enabling them to envision futures for themselves without the victim”.^[333] Some research highlighted that GPS EM is a fairer system because it protects perpetrators from false allegations by the victim^[334] and allows the perpetrator to avoid accidental contact with the victim through early warning systems.^[335]

Practitioner perception

Three police respondents, interviewed for the 2007 Scottish Government review on EM as a condition of bail, expressed frustration regarding whether EM would necessarily increase compliance of perpetrators who already routinely breached bail, especially in relation to domestic abuse.^[336] A majority of (judicial, SCTS, COPFS, bail officers, advocacy service and EM staff) respondents also stated they did not believe EM as a condition of bail would prevent perpetrators intimidating witnesses. 

By contrast, the recent Ministry of Justice evaluation on GPS EM found there was support amongst stakeholders for the use of GPS to monitor domestic perpetrators.^[337]  It was noted, however, that responses to breaches would need to be very efficient to ensure victim safety, as the tag did not prevent breaches only monitored them.^[338]

The evidence base on EM and Domestic Abuse

Compliance and reconviction are the focus of studies on EM and domestic abuse. 

Discussions on compliance and reconviction are the focus of a small number of empirical studies on EM and perpetrators of domestic abuse. As noted, the results of quantitative research of this type must be evaluated with some caution, as reduced reconviction may not necessarily be a measure of the effectiveness of EM.

As there are only a few studies on compliance and reoffending in relation to EM in domestic abuse cases, the following section offers a brief review and highlights the key findings of each of these publications.

GPS Monitoring Technologies and Domestic Violence: An Evaluation Study, Erez et al. 2012

Key finding: Domestic abuse perpetrators were less likely to breach if they were monitored using GPS rather than RF technology, and less likely to reoffend during the period of monitoring.

A study by Erez et al. (2012) is the most comprehensive study on the use of EM in domestic abuse cases. Using a quasi-experimental design, it examines the use of pre-trial EM in three jurisdictions in the USA, examining data on 2052 perpetrators of domestic abuse over two years, 1000 perpetrators over 6 years and 604 over one year; a web survey of 616 practitioners; and 210 qualitative interviews with victims, perpetrators and criminal justice/social services practitioners. 

Erez et al’s (2012) research found that perpetrators subject to GPS monitoring violated the conditions of their EM less than those perpetrators on RF EM. Practitioners also reported that less than 7% of perpetrators breached the conditions of pre-trial EM by entering exclusion zones. 

Whist there was a lack of consistency in re-arrest rates across different localities,^[339] overall there was a higher rate of re-arrest in the long-term compared with the period of monitoring for both RF and GPS perpetrators, suggesting that perpetrators are less likely to commit crime during the period of monitoring. In terms of preventing failures (i.e. breaches of EM conditions), GPS EM was found to be more effective than RF.^[340]  

The likelihood of reconviction was higher for perpetrators who were subject to GPS monitoring, however the authors suggest this may be due to increased reporting by victims, as they are better engaged in the criminal justice process via GPS EM methods.^[341]  Qualitative evidence provided that victims whose abuser was on RF EM also felt an increased willingness to report (as compared with prior instances of abuse when the perpetrator was unmonitored) due to being supported by the technology.^[342] 

Specialization and the Use of GPS for Domestic Violence by Pretrial Programs: Findings from a National Survey of U.S. Practitioners, Gur et al. (2016)

Key Finding: The majority of practitioners in the study were positive about the use of EM in domestic abuse cases and felt it can restore victims’ faith in the justice system.

A report by Gur and colleagues^[343] further analysed part of the data set from Erez et al’s (2012) study. They looked at the survey responses of 616 EM practitioners which provides further insights into practitioners’ understandings and motivations for use of EM in domestic abuse cases. The majority of EM practitioners were positive about EM use in domestic cases, stating that it improved their ability to sufficiently monitor perpetrators and hold them accountable, and the majority believed EM effectively deterred perpetrators from initiating ‘in-person’ contact with their victim. 

An Evaluation of the Use of Electronic Monitoring as a Condition of Bail in Scotland, Barry et al. 2007

Key finding: The use of EM as a condition of pre-trial bail is under-used in Scotland.

A 2007 Scottish Executive report^[344] on the use of EM as a condition of bail evaluated the effectiveness of EM as a condition of bail for 63 accused people across three Scottish courts. Of the 63, only 6 perpetrators of domestic abuse were included in the sample, therefore it is difficult to draw any meaningful conclusions. The report noted that very few “restricted from” conditions were used in EM bail, rather perpetrators tended to be “restricted to” an address. Of note, two of these perpetrators breached their conditions by entering an exclusion zone, one was arrested but neither were convicted of the breach.^[345]  Data is not recorded by offence type and thus very few conclusions can be drawn regarding perpetrators of domestic abuse. 

Scottish and International Review of the Uses of Electronic Monitoring, Graham and McIvor, 2015

Key finding: the evidence base on the use of EM in Scotland is limited. 

Graham and McIvor dedicate a section of their report to reviewing the evidence on EM and domestic abuse. Their review is based on a systematic review of existing literature rather than new empirical evidence on DA and EM. The review takes account of the studies identified above and notes that there is limited available research in this field. The authors highlight that in other jurisdictions EM is integrated with other community supervisions.^[346]

The only identified instance of a BEM pilot scheme for perpetrators of domestic abuse in the UK is a trial between 2014 and 2017 by Northumbria Police.^[347]  

This pilot was part of a wider Home Office-funded MATAC process implemented in Northumbria between 2014 and 2017. The original intention of the pilot was to use GPS EM to monitor bail conditions, Domestic Violence Protection orders (DVPOs) and prison release conditions. Use of EM for these purposes required authorisation from the Ministry of Justice and this was not granted.^[348] The scheme was therefore conducted on a voluntary basis and the cohort of users was self-selecting.

Victims were given a handheld GPS device and perpetrators were subject to a GPS tag to monitor their movements and any contact. Fixed exclusion zones were defined around the victims’ houses and places of work, and mobile exclusion zones set up around the victim to prevent unwanted contact outside of the static zones. 

Programme director of the pilot, Superintendent Deborah Alderson, provided that where the devices were deployed, they “worked effectively and gave the victim peace of mind and feelings of safety”.^[349]  Superintendent Alderson identified that there were several technical issues related to loss of coverage but believed that new technologies would be able to address the issue. On EM technology, she stated “I have found that technology changes so quickly, if I were to consider use of these again in the future I would consider lease of the units rather than purchase, so that units are kept up to date as part of the contract as technology advances.”^[350]  She also highlighted hidden costs relating to training police to respond to breaches and the costs incurred by the monitoring company. 

To further explore the use of community sentences in Scotland, statisticians at the Scottish Government have analysed the reconviction rates of perpetrators of domestic abuse by sentence type. 

For the period 2017/18, 2691 people were sentenced to RLOs, 332 (12%) of which had a domestic abuse marker.^[351]

One year reconviction rates for domestic and non-domestic abuse crimes and offences for the 2015/16 offender cohort were examined. The cohort includes those that were either released from a custodial sentence, or given a non-custodial sentence, in a Scottish court in 2015-16. The earliest occurrence of either a release from a custodial sentence or being given a non-custodial in the financial year is counted as the index conviction of an offender. Subsequent convictions in a year period after the index conviction are counted as reconviction. See  Annex A in Reconviction Rates in Scotland: 2015-16 Offender Cohort for further detail on the methodology for counting reconvictions. 

The cohort of 44,036 perpetrators was separated into those who had an index crime with a domestic abuse marker and those that did not, and reconviction rates were calculated both for both groups. These results were split by  disposal type, including RLOs and custodial sentences. Appendix 1 contains the table detailing the reconviction rates.

In Scotland, there is a lower reconviction rate for domestic crimes/offences for perpetrators sentenced to RLOs than to short prison sentences. 

The analysis found that 19% of perpetrators  who were imprisoned for under one year were reconvicted for another domestic abuse offence within a year. This compares with perpetrators sentenced to RLOs, 10% of whom were reconvicted for another domestic abuse offence within a year.

However, it is important to note that the differences in reconviction rates may be explained in part by the type of perpetrator most likely to be sentenced to imprisonment, as perpetrators at high risk of reoffending are less likely to be sentenced to RLOs in the first place.

The evidence base on EM and domestic abuse is limited 

This review did not identify any studies which compared outcomes for perpetrators of domestic abuse on EM with outcomes for a matched sample who serve their entire sentence either in prison or on a community sentence with no EM intervention. Without a matched comparison group it is very difficult, if not impossible, to draw robust conclusions regarding the effectiveness of EM with perpetrators of domestic abuse compared with other sentences. 

Following an extended review, a 2015 report by the SCCJR concluded that, in relation to BEM and perpetrators of domestic abuse, “(t)he empirical evidence and criminological literature on GPS-based bilateral EM is limited and relatively new, and it is too early to make strong claims about its impact”. This was echoed in the 2015 report by Lockhart-Mirams and colleagues who recommended that the UK government implement a mandatory pilot scheme for perpetrators of domestic abuse as a means of developing the evidence.^[352]