GPS, Satellite Tracking, Electronic Monitoring and Criminal Offenders



Is there hope for the future of community supervision?

GPS tracking may be one of two programs that offer an effective strategy for monitoring offenders.

GPS tracking is difficult, labor intensive and expensive (but it is cost effective).

Fourth in a series of articles on parole and probation research and practice.


By Leonard A. Sipes, Jr.

Thirty-five years of supervising public affairs for national and state criminal justice agencies. Former Senior Specialist for Crime Prevention for the Department of Justice’s clearinghouse. Former Director of Information Management for the National Crime Prevention Council. Graduate-Post Master’s degree-Johns Hopkins University.


GPS tracking of criminal offenders is a complicated, detailed endeavor that is being evaluated and considered throughout the United States. It’s far more labor-intensive, complex and nuisanced than first envisioned.

The use of GPS only applies to two percent of the US offender correctional population, but research to date as to effectiveness is encouraging.

In a world of limited results from other forms of offender community supervision, GPS may be one of the two best programs we have that provides encouraging results.

The other potential success is Project Hope and its variations being implemented throughout the country. Both are based on an immediate response to violations, thus holding the offender accountable for his actions.

Most Community Supervision Programs Provide Marginal Results

The track record for most prison or community rehabilitation programs is either marginal or shown not to have an impact at all, including the best program the federal government offered focusing on serious and violent offenders. Some programs have made things worse (recidivism increased).

Has the President or Congress (or anyone) funded comprehensive research designed to make sure the rest of us know what works as to rehabilitation or supervision programs? Nope.

With data showing that two-thirds of released offenders will be rearrested in three years (there is state data showing that 85 percent of some categories of offenders are rearrested for the same period of time) and that 50 percent go back to prison, the contribution of former prisoners to the crime problem is immense. With the majority of crime not reported, and the majority of reported crime not resulting in an arrest, we know that the numbers are higher than those stated above.

Some Background

GPS, or Global Positioning Systems or satellite tracking is different from radio frequency units (RF), which track offender movements in and near a home. Both are referred to as electronic monitoring.

When GPS was first introduced, we envisioned a day when all violent offenders released from prison or those on probation would be placed on GPS and allowed to work their way off. Logistically, without a massive infusion of resources, that vision is impossible.

Real time tracking is possible “if” you are willing to devote enormous resources. The vast majority of GPS is based on a review of data the day after. Remember that most parole and probation agents work Monday through Friday during daylight hours.


As stated above, the implementation of GPS tracking is far more complicated than first envisioned. Parole and probation agents can easily be overwhelmed by the data. Most parole agents see their offenders twice a month at most, thus daily intake of data can easily be beyond an officer’s capacity.

There are equipment problems. Offenders break curfew by short distances. They forget to charge the units. The problems (and data points) are endless.

Some agencies hire companies selling the units to do the tracking and communicating with the offender, and that helps. But in a system with huge caseloads (150 to one is normal) and infrequent contact, any communication either with the offender or tracking company can be overwhelming.

If your offender is suspected in criminal or questionable activities, the analysis of data points and overlaying them with maps and Google Earth is extremely time consuming. All of this provides some clarity when examining data from Pew.

There Are Three New Reports That Provide Clarity

Per Pew (edited)

The number of accused and convicted criminal offenders in the United States who are monitored with ankle bracelets and other electronic tracking devices rose nearly 140 percent over 10 years, according to a survey conducted in December 2015 by The Pew Charitable Trusts. More than 125,000 people were supervised with the devices in 2015, up from 53,000 in 2005.

All 50 states, the District of Columbia, and the federal government use electronic devices to monitor the movements and activities of pretrial defendants or convicted offenders on probation or parole.

The survey counted the number of active GPS and radio-frequency (RF) units reported by the companies that manufacture and operate them, providing the most complete picture to date of the prevalence of these technologies in the nation’s criminal justice system.

Despite the substantial growth of electronic tracking during the study period, it remains relatively rare in the context of the U.S. corrections system. Nationally, nearly 7 million people were in prison or jail or on probation or parole at the end of 2014, but individuals tracked using electronic devices in 2015 represented less than 2 percent of that total.

 Although some research suggests that electronic monitoring can help reduce reoffending rates, the expanded use of these technologies has occurred largely in the absence of data demonstrating their effectiveness for various types of offenders at different stages of the criminal justice process.


National Institute of Justice Standards

There are new (and much needed) technical standards for GPS tracking; see a recent article in Tech Beat Magazine at

See the technical standards at

New technical standards provide clarity as to systems, procedures, what the equipment is capable of doing, and what jurisdictions need to know to implement or expand a GPS program.

Not a Panacea

The use of GPS Technology is not a panacea and will not replace one-on-one interaction and data exchange by the supervision officer, but it is a helpful tool to assist in supervision.

It is typically employed as a sanction for non-compliance among high-risk offenders and those with specific geographic limitations (such as stay-away orders).  It is also used to monitor those who refuse to maintain or actively seek employment.

GPS can greatly increase a parole and probation officer’s ability to protect the public.  Local news in Washington, D.C. reported a string of assaults on teenage girls in a particular neighborhood.  Police provided a sketch of the suspect to the media in order to solicit the public’s assistance with the investigation.

An alert parole officer saw the sketch on the news broadcast and recognized the subject as a high-risk parolee on GPS.  She immediately checked the individual’s whereabouts at the times of the assaults and placed him at the crime scenes.  She visited his home to verify that his car matched the description of the vehicle used in the crimes.  She then arranged for the man to come into her office, where he was arrested.

An Enormous Responsibility

Implementing GPS tracking places an enormous responsibility on any agency.  GPS provides a great deal of additional information on each offender.  Learning to interpret and respond to that information is a challenge for even the most experienced parole and probation officers.

Generally, a parole and probation agent will review daily reports indicating whether the GPS unit transmitted appropriately and whether the offender remained in compliance with location parameters, and an incident hit report, which details whether offenders on GPS were in the vicinity of crime locations

The parole and probation agent can also review the actual tracking data, which shows the offender’s movements.  For some types of offenders, including high-risk sex offenders, daily review of the tracking report is required.

A parole and probation agent follows the movements of a particular sex offender on the previous day.  With a few keystrokes, she lays a detailed map of the city over the tracking report.

For an even higher level of detail, she superimposes satellite images from Google Earth over the offender’s movements.  Suddenly, a daycare center with a playground appears in the offender’s path.  She now has a good idea why that sex offender has been loitering in the area.  She and her team also share intelligence with the police and use it to inform their own surveillance and case management activities.

They use polygraph tests, GPS, drug testing, surveillance and other forms of human and technological intelligence with sex and high-risk offenders, but they are only as good as their ability to interpret and react to the data they get.  Parole and probation agents are not perfect, and offenders will test the capabilities of the system, but GPS provides some of the best tools in the country to provide accountability.

Offenders try to “get around” GPS in a variety of ways—some as simple as failing to charge the unit or attempting to cut it off.   One of the ways that GPS is tamper-resistant is “double” monitoring; the offender is tracked not just by satellite but by cell phone towers as well.  GPS transmission may be hampered in large buildings or homes, but supplemental devices can be placed in those buildings to continue transmission.


One of the few evaluations that include both GPS and radio frequency monitoring was completed in 2006 by Florida State University’s College of Criminology and Criminal Justice.  The study (“Under Surveillance: An Empirical Test of the Effectiveness and Consequences of Electronic Monitoring”) concludes that electronic monitoring has produced promising results:

“Overall, Florida’s program is found to provide an effective public safety alternative to prison for serious offenders, including those convicted of murder/manslaughter, sex offenses, robbery, and other violent offenses…Our findings indicate that electronic monitoring actually reduces the likelihood of revocation for a technical violation for offenders on home confinement. More importantly, electronic monitoring also reduces the likelihood of revocation for a new offense [emphasis added] and the likelihood of absconding which demonstrates a positive effect on public safety.”

The authors conclude:  “…it appears likely that the use of electronic monitoring devices will increase dramatically in the very near future.”


Newer Research

A newer study (“A Quantitative and Qualitative Assessment of Electronic Monitoring”) was offered by the Florida State University in January of 2010. It provides the latest update of previous studies using GPS and other forms of electronic monitoring.

The report indicates, “The balance of evidence from these studies shows that EM is effective in reducing supervision failure rates, as measured in a variety of ways.”

Researchers examined 5,034 medium- and high-risk offenders on EM and 266,991 offenders not placed on EM over a six year period plus interviews with staff and offenders. Selected findings include:

  • EM reduces the likelihood of failure under community supervision.  The reduction in the risk of failure is about 31%, relative to offenders placed on other forms of community supervision.
  • EM allows offenders to remain in the community thereby promoting family ties.
  • EM supervision has less of an impact on violent offenders than on sex, drug, property, and other types of offenders, although there are significant reductions in the hazard rate for all of these offense types.
  • There are no major differences in the effects of EM supervision across different age groups.
  • There were no major differences in the effects of EM for different types of supervision.
  • Approximately 1 in 3 EM offenders would have served time in prison if not for the electronic surveillance option available to the courts.


 Cost Effectiveness

Washington State Institute for Public Policy, “Electronic Monitoring (Probation),” June 2016, indicates cost effectiveness of GPS over time.


Research Summations from Crime Soputions.Gov

The following GPS programs are rated promising by Crime Solutions.Gov:

Electronic Monitoring (Florida) Uses systems based on radio frequency or global positioning system (GPS) technology to monitor offenders’ locations and movements in community-based settings. The program is rated Promising. Compared with the control group on other forms of community supervision, the technology reduced the risk of failure to comply.
Global Positioning System for High-Risk Gang Offenders (California) Monitors and tracks the movement of parolees categorized as high risk for gang involvement or activity. The program is rated Promising. Parolees monitored by the GPS program had significantly less arrests for new offenses and violent offenses, but had higher odds of technical violations.

Improved Public Safety

GPS is a useful tool in community supervision but “It’s not foolproof. Nothing’s foolproof. If people want ironclad guarantees that the offender will not commit additional crimes in the community, their only alternative is incarceration.

Despite its many limitations, GPS helps parole and probation agencies achieve goals of protecting the public through effective community supervision.

Crime in America at

Contact us at Media on deadline, use

My book: “Amazon Hot New Release”- “A Must Have Book,” Success With The Media: Everything You Need To Survive Reporters and Your Organization available at Amazon




  1. […] I was writing an article suggesting that Project Hope and GPS (satellite tracking) of offenders offered the best track record as to reductions in recidivism, see…. […]

%d bloggers like this: