An ankle monitor, often employed by law enforcement as a surveillance tool, serves as a tether to the justice system for individuals on parole or house arrest. According to the Pew Charitable Trusts, electronic monitoring, including ankle monitors, was used for over 125,000 offenders in 2015. These devices, which lock securely around the wearer's ankle, utilize GPS technology or radio frequency to transmit location data to a monitoring center, ensuring compliance with court-ordered movement restrictions. In certain cases, as reported by the National Institute of Justice, ankle monitors can also detect alcohol consumption, a feature critical for enforcing restrictions on individuals with alcohol-related offenses. The ankle monitor police use is a sophisticated blend of technology and law enforcement, aimed at maintaining public safety while allowing offenders controlled freedom.
In most cases, an ankle monitor system consists of three main components: an ankle bracelet, an on-site receiver, and a remote receiver. When tethered around the ankle, the bracelet unit takes regular or constant readings of desired information, such as the user’s location. Using either radio transmission or GPS technology, these readings are sent to an on-site transmitter, usually located in the user’s home. Next, the readings are relayed to a remote receiver, which may be located at a police station or monitoring service center. If the readings indicate a breach by the user, such as leaving the home while under house arrest, the proper authorities are alerted and act accordingly.
Usually, an ankle monitor is locked into place to allow for ongoing, accurate monitoring. Some units have inbuilt sensors which notify authorities should users attempt to remove them or interfere with their performance. The fact that it cannot be removed is partially responsible for the monitor’s alternate name: the tether.
One of the most common uses for an ankle monitor is the supervision of a wearer’s location. Generally, this information is needed because the wearer is either under house arrest or on parole. Either way, the use of a monitor can prevent the need for constant supervision of the offender by a law enforcement officer. Some studies suggest, however, that use of these monitors may be less effective in discouraging further crimes by the wearer than other rehabilitation programs.
Another popular use for the ankle monitor is the measurement of alcohol consumption. In this case, the device analyzes the sweat to determine whether it contains alcohol. Usually, this type of monitor is used for this reason because the wearer has committed a serious alcohol-related offense, such as driving while intoxicated. An ankle monitor may be imposed as a punishment or rehabilitation tool which prevents the offender from consuming alcohol for a fixed period of time.
How Far Can You Go With Ankle Monitor?
The distance an ankle monitor wearer can travel is determined by several factors. Number one is what distance the technology itself permits. Usually, receivers have a maximum transmission distance between 50 and 150 feet. Many systems also require the wearer to be within 25 to 30 feet of the home unit in order to upload and send data at specific times.
Ultimately, a judge decides upon an allowable distance. These permitted distances are based on the needs of the wearer and the reason for the monitor. Many cases are considered house arrests. In these situations, the wearer is generally not permitted to leave his or her designated home address. If the individual does attempt to leave the court designated area, then the ankle monitor physically alerts the wearer and signals the proper authorities.
Some ankle monitor setups allow the wearer to travel outside the home. In these cases, the courts determined that the wearer needs to travel to some additional locations. These might include:
- traveling to and from work
- going to religious services
- attending parole meetings or court hearings
- leaving to receive medical services
- attending rehabilitation services
Often, travel like this is restricted to specific times and scheduled ahead of time, so that the authorities monitoring the bracelet's location know when and where it should be. For emergency and unscheduled events, the wearer is usually supposed to notify the proper people and receive permission to leave.
If the only reason for wearing the ankle bracelet is to control alcohol consumption, the device may not restrict movement. In these instances, the wearer can move about freely as long as they abstain from alcohol. These situations are rare though, as most alcohol monitors still track and restrict a wearer's movements.
How Do Ankle Monitors Work?
Ankle monitors often serve as an alternative to traditional incarceration. Jail systems are regularly overpopulated and unable to take in any new offenders. Ankle monitors provide the ability to punish some individuals without having to place them in prison. Qualifying house arrest individuals usually committed some type of lesser or non-violent crime. Some offenders get out on good behavior before their sentence is complete. Wearing an ankle bracelet might be a stipulation of this release. Sometimes parole officers also utilize ankle bracelets for their parolees.
Ankle monitors work by notifying monitoring agencies about a wearer's whereabouts and/or alcohol consumption. When a judge assigns an ankle monitor to an individual, the judge will usually calibrate the monitor to restrict the wearer to an assigned geographical area or to a specific alcohol consumption level. Depending on how the monitor is set up, it signals the authorities or monitoring agents if the:
- wearer leaves the designated area
- unit requires charging
- wearer attempts to remove, tamper with, or shield it
- wearer nears an off-limits location
- bracelet detects alcohol
- wearer strays from a specified location or schedule
- system malfunctions
Most monitors relay some type of locational information. Some models are more precise than others and some devices detect and relay multiple things. Some bracelets transmit constantly and others record data at specified intervals.
Types of Ankle Monitors?
There are three main types of ankle monitors. All can track the location of the wearer, but they differ in how and when they do so and what information they relay. Which type a wearer receives depends on the nature of his or her crime(s), the reason for the monitor, the restrictions desired, the travel distance allowed, and the type and amount of information wanted.
1. Radio Frequency (RF)
RF monitors work by informing the monitoring party about the general whereabouts of the device in relation to the home-based unit. Generally, these monitors do not give an exact location, but instead, notify when the device comes into range or departs a designated area. These monitors are often used for curfew purposes and house arrest cases, where the individual is supposed to be in a specific place at specific times.
2. Global Positioning System (GPS)
GPS ankle monitors divulge specific geographical coordinates for the wearer. They are often very precise and can transmit location data continuously or at regular intervals. These monitors are useful for allowing individuals to travel about according to prearranged schedules. These bracelets also help restrict some offenders from going too near certain locations or people.
3. Secure Continuous Remote Alcohol Monitoring (SCRAM)
SCRAM systems can monitor location as well, but their main purpose is to detect alcohol. They periodically test the wearer's sweat for alcohol content and report it to the monitoring organization. SCRAM units are most often used for repeat driving under the influence (DUI) cases.
