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GPS Supervision in California: One Technology, Two Contrasting Goals

Two NIJ-supported studies with very different results show that GPS technology may be used to help prevent crime in various ways.
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National Institute of Justice Journal
Date Published
July 15, 2015
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NLECTC-Corrections Technology Center of Excellence, University of Denver (see reuse policy).

Using sophisticated technology to control crime generally appeals to both the public and policymakers because it prompts visions of reduced crime and improved safety. GPS technology can track a person on parole or probation's movements in real time and is designed to reduce crime by enhancing the likelihood that law enforcement will detect criminal behavior. For the public, this conveys the notion of a virtual prison, in which those convicted of an offense are prohibited from engaging in any wrongdoing. Critics, on the other hand, maintain that the idea of pervasive and constant surveillance offers a false sense of security and does little to actually prevent crime; they often point to horrific crimes that have occurred while those convicted of an offense were under GPS supervision.[1]

Despite the absence of solid evidence for either position, the potential benefits outweighed the criticism and spurred many communities across the country to invest in GPS supervision equipment in the mid-to-late 2000s. Among these were two California counties that initiated programs that were structurally similar but conceptually quite different. The California Department of Corrections and Rehabilitation (CDCR) began a pilot program in San Diego in July 2005 to test the use of GPS technology as a deterrent for high-risk persons convicted of a sex offense on parole. Parole agents had generally positive experiences with the program to monitor those convicted of a sex offense, which prompted CDCR to expand the program across the state.

Meanwhile, interest grew in applying the same technology to address the state's serious gang problem. In March 2006, CDCR partnered with the city of San Bernardino to implement a 20-unit pilot project using GPS supervision for those convicted of an offense who are in a gang. In May 2007, then Governor Arnold Schwarzenegger expanded the pilot program, adding 20 units each to Fresno, Los Angeles, Riverside and Sacramento.

The growing interest in using GPS technology as a supervision tool, coupled with the dearth of existing research and continued advancements in the technology, prompted NIJ to fund methodologically similar yet distinct evaluations of the two California programs. The goal was to understand whether GPS supervision would work with one or more groups and, if not, why not.

The study of those convicted of a sex offense[2] used a quasi-experimental design to compare 258 persons convicted of a sex offense receiving traditional parole supervision with 258  persons convicted of a sex offense receiving GPS supervision. The study looked at two main outcomes: noncompliance (measured by violations of parole) and recidivism (measured by re-arrest, reconviction and return to prison). The researchers found that persons convicted of a sex offense who received traditional parole supervision were three times as likely to commit a sex-related violation as those who received the GPS supervision. In terms of recidivism, persons convicted of a sex offense who received traditional supervision were twice as likely to be arrested as those who received the GPS monitoring supervision. Overall, these findings were consistent with most of the recent research, which has found the deterrent value of GPS technology.[3]

In a thought-provoking twist, however, the gang study[4] offered very different findings from those of the study of those convicted of a sex offense, despite having a geographically similar population and a program that operated under almost parallel procedures with the exact same hardware. In this study, researchers looked at a group of gang-affiliated persons convicted of an offense who were released from prison and residing in California: 392 of them receiving GPS supervision and 392 receiving traditional parole supervision. Again, the researchers examined two main outcomes: noncompliance[5] and recidivism. In contrast to the persons convicted of a sex offense, however, the odds of a technical violation were 36 percent greater among the gang-affiliated persons on GPS supervision, and the odds of a nontechnical violation were 20 percent greater. Conversely, the GPS group was less likely than the traditional supervised group to be re-arrested overall (the chance of being re-arrested was 26 percent lower). (CrimeSolutions rates California's GPS supervision program for gangs as "promising." For more information, visit the CrimeSolutions profile of the program.

At first glance, these contradictory findings may confirm many criticisms leveled at GPS and give corrections personnel pause when considering the use of GPS to supervise gang members. Moreover, the lack of consistent findings from the two studies draws into question the universal utility of GPS as a supervision tool. However, if we look closely at the purpose, goals and operating procedures of each program, we find quite a different story.

Using GPS in California

GPS technology is a global navigation satellite system that provides location and time information, in all weather, anywhere on or near the earth. Initially developed in 1973 as a military application, the system today is freely accessible to anyone with a GPS receiver. In corrections, GPS technology is used to track the real-time movement of a wide variety of persons convicted of an offense (e.g., drunk drivers, gang members, those convicted of domestic violence) within different criminal justice contexts (pre-adjudication, dispositional and post-release).[6]

In California, the Department of Adult Parole Operations uses GPS to monitor both paroled high-risk gang members and persons convicted of a sex offense. Although the two programs are discrete, they do have some similarities (see Table 1). For instance, rather than offering GPS as a standalone practice, both programs integrate GPS technology into an overall supervision program. As a result, both programs have two distinct components: GPS monitoring and traditional intensive supervision.

The GPS monitoring component uses an active system — meaning that a data point is taken every minute and transmitted nearly in real time — that combines cellular and GPS technology to automatically track a person on parole's location. The tracking device is a single-piece GPS unit that weighs about 6 ounces and is roughly the size of a computer mouse. They wear the device flush around the left ankle; specialized screws secure a tamper-resistant, fiber-optic technology strap to the device.

Table 1. Characteristics of Sex Offense and Gang Parole Supervision Programs
Program Characteristics Sex Offense Program Gang Program
Strategy Deterrence/rehabilitation Focused deterrence
Goal Return to community Remove from community
GPS type Active and passive Active
Duration Length of parole period Intermittent (as needed)
Caseload 20 high/40 passive 20
Eligibility Static-99 risk assessment instrument Gang attribute assessment criteria
Equipment Single piece Single piece
Monitoring model Vendor operated Vendor operated
Notification system Yes Yes
Supervision Specifications
Subject matter training Yes (sex offenses) No
Orientation for person monitored Yes Yes
Drug testing If applicable Mandatory
Supervision specifications More contacts per month Fewer contacts per month
Integrated with traditional parole Yes Yes
Treatment option Yes No

The software system tracks information about the activities of persons on parole and transmits it to a monitoring center. The monitoring center then provides the supervising parole agent with information in two basic forms: daily summary reports (DSRs) and immediate alert (IA) notifications. The agent receives an emailed DSR for each person on parole every morning detailing all activity recorded by the GPS unit, including charging activity, zone violations, strap tampers and other violations. The agent must review all recorded activity and note any follow-up actions. The DSR also includes a direct link to a Web-based data system, which allows an agent to review an individual's movement patterns. When the GPS unit records specific types of violations, an IA notification is generated automatically and transmitted via text message to the supervising agent. The supervising agent must then analyze and respond appropriately to the information.

The GPS monitoring technology in California's sex and gang offense programs also includes:

  • Inclusion zones: Locations that an individual must occupy during certain times of the day
  • Exclusion zones: Locations that an individual is prohibited from entering at all or during certain times of the day
  • Crime scene correlation: The intersection of crime incident data with GPS tracks to determine whether an individual was in the vicinity of a crime

The intensive supervision component involves more traditional, recurrent physical contact: The agent meets face to face with the person on parole and other collateral contacts on a regular basis. It also includes a drug-testing element if applicable.

Several critical differences exist between the two programs, however, and these differences likely drive the divergent outcomes. The first difference is that the program for those committing sex offenses includes a treatment component, which requires persons on parole to attend weekly treatment classes in which clinicians provide psychological evaluations, assessments and individual and group therapy. Notably, the gang program does not include a treatment requirement. The reason for its absence is simple and offers the second major difference between the programs: The operational goals of the two programs differ markedly. The goal of the program for those committing sex offenses is to use GPS technology to gather information that can enhance supervision, heighten the certainty of treatment and discourage future crime; the goal of the California gang program — as for many other gang programs — is to remove individual gang members from the community by quickly identifying violations, enforcing strict revocation rules and returning the person convicted of a sex offense to prison.[7] The findings from the two studies suggest that GPS can be used for either purpose with relatively equal efficiency.

Policy Implications

GPS has garnered an increasing amount of attention in recent years. The use of GPS technology as a supervision tool is in vogue in contemporary criminal justice systems and still growing in popularity. In fact, most jurisdictions throughout the Western world have some form of electronic monitoring to supervise persons convicted of an offense.[8]

The findings from the California studies are important because they suggest that GPS technology might serve multiple crime prevention purposes, depending on a program's goals and structural design. Specifically, GPS can be used as a traditional deterrent mechanism, a focused deterrent tactic or a treatment enhancement provision.

Traditional deterrence: Deterrence is based on the notion that all behavior results from rational calculations of cost versus reward and that to prevent crime, the costs must outweigh the expected rewards.[9] In general, deterrence suggests that if we increase the certainty, severity and swiftness of criminal justice sanctions, we could prevent crime.[10] With these principles in mind, it is easy to appreciate how the use of GPS might increase the certainty — and possibly the swiftness — of punishment. GPS's intensified supervision likely enhances the probability that law enforcement will detect parole violations and criminal behavior, and the location data obtained by GPS systems presumably increase the speed in apprehension, which in turn might result in more rapid punishment. The use of GPS also might increase the severity of punishment: It can strengthen confidence in evidence that points to an person's guilt of a post-release violation or crime, resulting in stricter penalties.

Moreover, GPS monitoring has an advantage over other deterrence-based programs in that it offers much broader supervision. Unlike traditional intensive supervision programs that simply increase contact between the parole agent and the person under surveillance, GPS technology offers continuous monitoring, creating an almost omniscient supervision presence that hinders all criminal activity. This type of unyielding supervision, further enhanced by a digital record of the individual's whereabouts, might tip the scale in a criminal's decision of whether to commit an illegal act.

Focused deterrence: Deterrence suggests that we could prevent crime if a person under surveillance perceives that the costs of committing the crime outweigh the benefits. Focused deterrence is a similar threat sanction approach used by criminal justice officials, but it differs in that it specifically warns high-risk individuals bout the sanctions for re-offense — that is, that police, prosecutors or probation officers will "pull every available lever" to maximize punishment.[11] Thus, again, GPS may be used to increase certainty, swiftness and severity, but parole agents can also closely monitor an individual's movements and strictly enforce any violation through revocation. Moreover, parole agents, in conjunction with law enforcement, can use GPS to disrupt gang activity by holding in violation two or more monitored individuals who come within close proximity of one another and by investigating crimes via crime scene correlation software, which can intersect GPS tracks with location-based crime data and help identify potential suspects or observers. The latter tends to dissuade non-monitored persons from associating with monitored gang members to avoid being exposed as an associate.

Rehabilitation: Rehabilitation focuses on reintegrating individuals back into society. A central component of the program for those committing sex offenses is mandated treatment. Numerous treatment options are available for persons convicted of a sex offense, and although research on their effectiveness has produced mixed results, the majority point to positive benefits. For instance, a recent meta-analysis examined 69 outcome evaluations of treatment for those convicted of a sexual offense, which comprised 80 independent comparisons between treated and untreated persons. The analysis found that despite a wide range of positive and negative effects, the majority of studies confirmed the benefits of treatment.[12] Overall, treated persons demonstrated 37 percent less sexual recidivism than those who did not receive treatment. The effects for violent and general recidivism were in a similar range.

Although it is still unclear what type of treatment is most effective,[13] the research seems to agree that those convicted of a sex offense who leave treatment before completion have an increased risk of recidivism.[14] Given this finding, it is feasible that when integrated into a treatment program, GPS monitoring might support rehabilitation efforts. The sense of omniscience that GPS engenders among those convicted of an offense might encourage them to continue their specified treatment regimens. Under traditional parole supervision, a person could haphazardly attend treatment and fabricate stories to explain missed appointments; however, GPS data greatly hinder this potential for subterfuge. In turn, increased and continued attendance in a treatment program might decrease the likelihood of criminal behavior.

A Multifaceted Tool

This review only touches briefly on how structural design and program goals factor in when bringing a GPS supervision program from conceptualization to reality. But perhaps the best way to think about GPS, given its multidimensional nature, is not as a program at all but as a multifaceted tool that can be configured in a number of ways to support varied criminal justice objectives.

For More Information

Read more about the California sex offense and gang studies.

About This Article

This artice appeared in NIJ Journal Issue 275, September 2015.

Date Published: July 15, 2015