Police say a new system of closed circuit television in Dunedin's Octagon has already proved its worth, allowing officers to respond to incidents far more quickly.
Fourteen closed circuit television cameras worth $200,000 have been monitoring activities in the centre of Dunedin since October.
Senior Constable Niall Shepherd says 12 people are before the courts because of camera evidence.
He says in the past officers arrived at incidents after they were over and those involved had gone, but now they can get to an incident when it is still happening.
Mr Shepherd says 47 trained and vetted police volunteers, working in pairs, monitor the CCTV screens.