Overview (How It Works)

Electronic Monitoring is a cost-effective alternative to prison custody, which provides a method of monitoring the presence or absence of a subject at a specified curfew location.

Electronic Monitoring works by the subject wearing a wristwatch-sized transmitter called a Personal Identity Device (PID) on the ankle or wrist. The Personal Identity Device is worn throughout the entire duration of the curfew order.

A Site Monitoring Unit (SMU) is the receiver, located in the place of curfew which is usually a subject's home, although additional Site Monitoring Units may be sited in places of work, education or training should the curfew order require.

The Personal Identity Device emits a regular encrypted radio signal received by the Site Monitoring Unit, which is then sent via either a PSTN or a GSM to the Monitoring Centre to confirm the presence or absence of a subject. If a subject is absent from a place of curfew during the hours of curfew, a violation is reported by the Site Monitoring Unit which is received by the Monitoring Centre within minutes.

Immediate attempts are made to establish telephone contact with the subject, directly followed by contacting the relevant authorities to enable any appropriate action to be taken.