Mr Hill said police abandoned any pursuit of the car given the age of the driver and concerns about what the boy would do if police chased him.
He said the boy was not only putting himself and his passengers at risk but also the safety of other drivers on the road.
"There was no way we were going to get involved in a pursuit. I was concerned for my staff and members of the public. [The driver] was putting way too many people at risk and I don't think they had any comprehension ... It concerns us that a 12-year-old would think it is okay to take a car and drive."
There were police cars stationed along the way and a police car travelled behind the stolen car but out of its view.
Mr Hill said one police officer clocked the driver at 147km/h.
Police received reports from a rural part of Tokoroa that the car had been driven up a driveway. The three boys tried to run but were caught by police.
Apart from the speed and not dipping his lights there were no other issues with the 12-year-old's driving, Mr Hill said.
The 12-year-olds have been referred to Youth Aid and the 15-year-old was due to appear in the Tokoroa Youth Court today charged with unlawfully getting into a motor vehicle. Mr Hill said further charges could be laid.