Types of House Arrest Monitors Used Today
Just as there are a number of reasons for someone to be under house arrest, so too are there a variety of types of house arrest monitors. The idea of using technology to narrow an offender’s scope of movement first arose in the 1960s.
It wasn’t until 1982, however, that the first electronic ankle bracelet was installed around a criminal limb. Since then, the use of house arrest monitors has expanded as the technology has become more advanced.
Radio Frequency Monitors: The First Generation
Broadly defined, ankle monitors transmit and receive information from a base. These sensors, or tethers, detect when the wearer of the bracelet has gone beyond the bounds of his permitted area. Initially, electronic monitors could report only whether the wearer was at home or not at home.
These radio frequency monitors were incapable of tracking movement. This kind of monitor is still used in circumstances when the wearer is confined to a single location.
[box type="info"]For instance, Lindsay Lohan served part of her jail sentence within her apartment while wearing a radio frequency monitor.[/box]
Two Kinds of Radio Frequency Monitors
The radio frequency ankle monitors can operate in one of two ways. A continuously signalling monitor sends messages to the base at brief intervals. An interruption means that the wearer has left the permitted area, has removed the bracelet or that the bracelet has malfunctioned.
A programmed contact device, on the other hand, calls the bracelet wearer at certain times. If he fails to reply, the receiver transmits this information to the parole officer. Damage to the bracelet will set off an alarm as well.
GPS Monitors: The Current Standard
The heyday of radio frequency monitors was in the period before the advent of wireless communications. The use of GPS in monitoring has extended the usefulness of the monitor. Satellites track the wearer’s movements. Law enforcement can present a record of these movements in court if called upon to do so.
Areas permitted to the wearer are extended beyond his home, and can vary with time of day. This allows those wearing the monitors to continue at their jobs.
The court officer can program a map that indicates where and when the wearer of the monitor is allowed to be. This may include work from 9 to 5 and the grocery store one afternoon a week. If the wearer goes outside of these limits, the monitor notifies his parole officer or police.
It was because she attended a forbidden yoga class, in fact, that Martha Stewart’s GPS-monitored house arrest was extended. GPS tracking is especially useful for other sorts of offenders, like child molesters or rapists, who must avoid a certain population.
Blood Alcohol Monitors
One type of monitor can identify whether its wearer has been drinking. A transdermal alcohol ankle monitor takes blood alcohol readings from the skin. In cases where alcohol abuse is a factor, such as drunk driving or domestic abuse, this information can be useful to the courts.
The bracelet also detects if an the user has tried to block its reading of the skin by slipping something inside the bracelet.
There are a couple of other types of house arrest monitors designed to read blood alcohol levels that do not require the wearing of an ankle bracelet. The breathalyzer monitor notifies the home-bound offender at any time of day or night that he must take a blood alcohol test.
If the offender either fails to respond to the demand for a test, or fails the test itself, the computer calls law enforcement. The ignition interlock device makes it impossible to start a car engine if the driver fails a breath test.
Voice Supervision Monitoring
Voice supervision is another method of house arrest that forgoes a monitor. Instead, telephone calls determine whether an offender is at home. In order to implement this system, the offender must have a land line telephone. Voice recognition software eliminates the possibility of fraud.
Often called voice curfew, this is the least expensive of all house arrest methods.
Other Uses for Monitors
Not everyone who uses these types of house arrest monitors is, in fact, under house arrest. Family courts may use monitors on schoolchildren at particular risk for truancy. To prevent patients from wandering away and endangering themselves, nursing homes commonly use radio frequency monitors.
Beginning in 2005, the Department of Homeland Security has been requiring some foreign nationals seeking asylum in the US to wear monitoring ankle bracelets. The department maintains the use of these monitors will reduce flight risk, but the move is a controversial one.