How they will track the Beast

Global Positioning System (GPS) tracking that will be used on sex offender Stewart Wilson will be so comprehensive monitors will be able to tell if he is running, in a car, or standing in the same place and for how long.

Wilson, 65, known as the Beast of Blenheim, has served 18 years of a 21-year sentence for sexual offending against women and girls including rape, indecent assault, stupefying, wilful ill-treatment and bestiality.

He has served the maximum time and can no longer be kept in jail. He will be let out on parole within the next three weeks and will be subject to unprecedented, strict release conditions. He will live in a house on the grounds of Whanganui Prison.

Among those conditions he must wear a GPS tracking bracelet that will allow Corrections Department staff to monitor his movements at all times.

Corrections community probation services assistant general manager Maria McDonald said GPS monitoring was being rolled out in New Zealand this month and 10 sex offenders on extended supervision would be tracked by GPS before Wilson. Wilson would be the first paroled sex offender to be tracked by GPS.

The GPS equipment was being leased from a United Kingdom provider. Corrections was in the process of employing monitoring staff, but Ms McDonald was unable to say how many people would be employed or where the monitoring centre would be.

GPS tracking bracelets required specialised tools to remove and tamper alarms would set off an alert if they were triggered. The bracelets tracked movements in almost real time and monitors would be able to see whether the wearer was stationary, walking, running or in a vehicle by their speed.

The bracelets gave valuable information about the wearers' whereabouts, what routes they chose to take, and how long was spent there, she said. Ms McDonald said exclusion zones would be set up for any areas bracelet wearers could not go, and in Wilson's case, the first of those would be outside his home on the prison grounds.

As part of his release conditions, he would be unable to leave the property unaccompanied, so any deviation from the plan would result in an alert, she said.

The monitoring centre would be issued with a plan of his activities for the week in advance, and any activity that deviated from the plan would trigger a response. What that response would be would depend on any breach.

Ms McDonald said she had travelled to London to see how the system was used there and spoken to an offender who was subject to tracking.

It had also been trialled in different scenarios and in different environments, including testing on the site where Wilson would be housed.

Steps had been taken to mitigate any technological concerns, for example, a bracelet required charging by the wearer, but would alert the monitoring centre if power was low.

If a wearer did not recharge a bracelet, it would trigger an alert.

Corrections said Wilson would be accompanied by local Prisoners Aid and Rehabilitation Society (Pars) staff when he left his house. Yesterday, the local Pars branch passed calls on to its operations manager Jane Hossack, in Christchurch.

She said Pars was providing Wilson with re-integration support in the community. That would include providing support staff to accompany him when he was out.

She would not answer any other questions about staff, including training and selection protocols.