Trending Topics

How GPS units can enhance offender monitoring

While GPS units can help monitor offenders, probation and parole officers must use them in conjunction with other supervision methods


In this Sunday, Nov. 13, 2016, photo, Luis Carlos, a construction worker from Honduras who is headed to Miami with his son, wears an ankle monitor as he sits at the Sacred Heart Community Center in the Rio Grande Valley border city of McAllen, Texas after he was released after processing by U.S. Customs and Border Patrol.

AP Photo/Eric Gay

It’s 10:30 at night and you are making a home visit. You find out your offender is not there and in violation of his 9 p.m. curfew. After a few phone calls and speaking with some of the offender’s family members, you discover he has decided to take a road trip to a town three counties away! You direct the offender to return home immediately and follow up with him the next day.

Just about every probation officer and parole officer comes across this scenario at some point during their career. We ask ourselves, “How do we go about addressing this violation?” One solution is to place a GPS unit on the offender.

How GPS can assist in monitoring an offender

Probation and parole officers can place a GPS unit on an offender as an intermediate sanction to help curb problematic behavior, or use a GPS unit in pre-trial settings instead of keeping an offender in jail.

This provides probation and parole officers with real-time information on an offender’s current whereabouts and information on the offender’s past whereabouts through the GPS program.

Probation and parole officers can set up inclusion zones the offender is required to be in during a certain time of the day or night and, if the offender leaves this area, the officer is notified the offender is out of place of assignment.

Probation and parole officers can also set up exclusionary zones in which the offender has been instructed to stay out of at all times. If the offender enters this area, the officer will be notified. The reason for the exclusionary zone will dictate the officer’s response.

GPS technologies evolving

GPS units have built-in security features that provide notification if the offender has tampered with, attempted to remove or removed the device. The most common way for an offender to remove the unit is simply by cutting the strap.

GPS systems also offer a point-tracking feature that allows probation and parole officers to set up a geo-fence around a certain area and then put in date and time ranges to see if any offenders entered the area. This is a much quicker method of searching an area to determine if an offender has been there instead of looking at GPS points for each offender, which could cover several days, weeks or months.

GPS units are part of a correctional toolbox

GPS is a great tool that has advanced over the years; however, it is just that, a tool.

Probation and parole officers may become too reliant on a GPS unit and assume the offender is no longer engaging in criminal behavior because they are outfitted with a GPS device, but this is not the case. Offenders constantly come up with ways to defeat GPS units or engage in criminal behavior by manipulating their whereabouts.

Officers cannot just sit back and check the offender’s GPS points and assume the offender is in compliance. Probation and parole officers must use GPS units in conjunction with other supervision methods.

GPS manipulation

Google “how to defeat a GPS ankle tracker” and you get thousands of results, ranging from ways to remove, hack or bypass the GPS unit.

Do all of these methods work? I don’t know. However, I do know that offenders have a lot of time on their hands to try these methods and see how their probation or parole officer responds.

An offender may cover the GPS unit with different materials to block the signal. If they are successful and are able to do it in a certain location of the house such as a basement, it may give the impression the offender is just losing the GPS connection when they enter that room.

Offenders can let the battery die to give them a short window of opportunity to move around without the GPS picking up their location.

Offenders may also attempt to stretch the rubber strap so they can remove the device without setting off the tamper alarm. Once the device is removed, they can leave the GPS inside their residence and are free to do what they want.

The offender may adjust their movement patterns and only go to public locations that would not raise any alarms or concerns with their probation or parole officer.

These are all reasons why probation and parole officers cannot rely on GPS units to police their offender’s actions.

For example, let’s say that prior to being outfitted with the GPS unit an offender delivered drugs to a house around the corner from a convenience store. Now they are just delivering drugs in the convenience store parking lot because they can still deliver to their customers and don’t want probation or parole officer to know they have any connections to that residence.

As we can see, while the GPS unit tells a lot, it does not tell the whole story. It will not tell us who the offender is associating with, if the offender is using drugs or alcohol, or if the offender is engaging in criminal activity.

Tipping the Scales

Probation and parole work is complex. One minute you’re a counselor addressing a drug relapse, the next a social worker helping an offender get proper services, and then the next minute you have to switch into an investigator role.

While “investigator” may not be in your job title, it is part of your job duties. If you truly want to see what the offender you are supervising is doing, get out of your office chair and on the street.

The GPS unit is a great tool that helps tailor your approach. You will know when the offender is at home, when they are at work and when they are running errands. The GPS unit can help you locate your offender without having to tip your hand that you are trying to find them. This can allow you to pick better times to do home visits, employment checks, spot checks and covert surveillance activities.

Conducting these activities will give you a better understanding of what the offender is doing.

If you see something suspicious when reviewing GPS points, go to that area to investigate. You never know what you might find out. For example, you might locate a surveillance camera at a business that was pointing directly to where your offender was two days earlier. Approaching the business and asking to review security footage might show the offender associating with a known drug dealer or driving when they don’t have a license.


GPS units are a great tool for probation and parole officers to help combat problematic behavior without having to arrest the offender. Yet it is only a tool and cannot be substituted for good investigative work.

Just because an offender is outfitted with a GPS unit and appears to be following all the rules, doesn’t mean they are. Probation and parole officers cannot become complacent and think the GPS unit will do their job for them.

Tyson Howard is a probation/parole officer with the 4th Judicial District Department of Correctional Services in Iowa, assigned to the High Risk Unit. He is a current member and coordinator for the Iowa Law Enforcement Intelligence Network and a member of the Iowa Narcotics Officer Association. Previously, he held the rank of officer and then sergeant with the Centerville (IA) Police Department for 6½ years. In addition, he was assigned to the South Central Iowa Drug Task Force Special Operations Group for 5 years. He received a Bachelor of Arts in Criminal Justice from Buena Vista University.