Trials of new voice verification and GPS (global positioning system) prisoner monitoring technologies show they can work well in New Zealand.
Manager Operational Policy and Planning Tracy Mellor says the trials were carried out using Corrections staff and volunteers, not offenders.
“The results show that the technologies can be operated in New Zealand to similar levels of accuracy and consistency as reported overseas.
“These technologies have the potential to improve Corrections’ ability to monitor offenders across a range of sentences and orders,” says Tracy.
Voice verification technology (VVT) The New Zealand trials were designed to test the system’s ability to identify an individual and confirm his or her location. The results showed a high level of accuracy but found that the technology cannot determine if a telephone call by an offender to the VVT system has been forwarded from a different telephone. The system also requires that the caller ID facility is not blocked.
“In the UK, this obstacle is overcome by hard-wiring a dedicated telephone into the approved location and directing all VVT checks through this telephone. The telephone and the line are fully controlled by the monitoring company,” says Tracy.
The system has been implemented in the UK corrections system and across several US states and agencies. Sweden, France and Australia are also investigating its usefulness. Global positioning system Tracy says passive tracking trials using satellite-based GPS took longer than expected due to technical issues but clearly showed the technology can accurately report the individual’s location at all times to the level of individual street name and number.
While all areas of New Zealand can be monitored, the signal was lost on some occasions during the trial when the satellite temporarily could not access the locating unit when it was under a dense object.
“This is a universal issue and not specifically confined to New Zealand, but the technology still offers some excellent opportunities,” says Tracy.
Phase II testing of both technologies will begin with about 20 offenders in mid-2006 for approximately six months.
The use of VVT in Phase II trials (and any potential future use) will be as an enhancement to existing electronic monitoring procedures, meaning the offender will be subject to other forms of electronic or manual monitoring as well as through VVT via a dedicated telephone line.
The next step is to trial VVT during approved absences (for example at work) where manual methods are not suitable but where the offender has access to an approved telephone.
Passive or retrospective tracking - recording and analysing data from the previous 24 hours - will be used in Phase II GPS trials. Active tracking relies on the immediate transmission of location information via cellphone. Where there is no cellular reception, a widespread problem in New Zealand, it is not possible to transmit the information immediately.
Public perception is that any type of tracking is active real time tracking and that the monitoring company can stop an offender from committing a crime. But unlike the movies, the monitoring company does not watch the offender’s every move on screen.
If an offender attempts to avoid being tracked by leaving the GPS locating unit at the approved residence, this will trigger an alarm. Evidence from overseas trials indicates that this happens infrequently and most offenders are compliant. Offenders know that avoiding being tracked or committing a breach could mean a return to prison.
VVT is a biometric authentication tool which verifies an offender’s identity by comparing his or her voiceprint during a telephone check against an electronically stored voiceprint. The offender is required to answer random telephone calls from the VVT system and to also make calls to the system from an approved telephone number.
GPS uses satellites that orbit the earth and enable people with ground receivers to accurately pinpoint their geographic location. This technology is widely used in navigation.
The offender wears a home detention bracelet and carries the GPS locating unit when outside the home. The two pieces send signals to each other and alert the monitoring company if they are not in close proximity.
GPS monitors the whereabouts of the GPS locating unit and plots this information on detailed maps. This data is uploaded to the monitoring centre on a regular basis but is not reported and analysed until a later time (passive tracking) or can be monitored in real time (active tracking). Inclusion and exclusion zones can be entered onto the maps and a record of any breaches of these zones is reported retrospectively.
This is a small data-collection sensor unit worn by the participant with builtin communication and computing capabilities.
The STaR Unit is a small, lightweight remote electronic monitoring, tracking and surveillance unit. The participant is required to carry the STaR locating unit whenever he or she is not in the home monitoring environment.
The DEU is generally located in the participants’ home and extends the range and monitoring capabilities of the STaR Unit when in the home monitoring environment.
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