Michael McDowell (Dublin South East, Progressive Democrats)

The second type of monitoring, which the Deputy referred to, is by GPS tracking. This is the remote surveillance of a person's location as he or she moves from place to place. It uses locational technology more often associated with tracking ships and other vehicles. It is more sophisticated than tagging, but the expectations, technical challenges and costs are higher too, as the Deputy would know.

The offender carries a personal tracking device which receives satellite or other signals and calculates its own location. The tracking device contains GSM or GPRS technology that allows the immediate transmission of location data to a control centre. The end product is a detailed map showing the offender's movements while tracked.

Its most obvious application is to monitor detailed compliance with specific requirements, for example, to stay out of an exclusion zone, observe a curfew or attend specified programmes, locations or other activities. Deputies may be interested to know that a leaflet distribution company in Dublin could show them a GPS print-out of where its people were to prove they were on one road or another. This shows the point the technology has reached.

Pilot GPS projects in the UK have found GPS in its current state of development not to be sufficiently reliable where the offender is between tall buildings or on the underground or trains. Compared to standard monitoring, GPS tracking is more expensive. The proposals for electronic monitoring in the Bill provide for both curfew-type conditions and exclusion conditions.

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