A short time later the car was seen again on the roundabout at State Highway 1 and Port Marsden Highway. It later crashed into a fence at Marsden Bay Rd.
A police dog unit tracked down a 17-year-old boy, who was arrested and charged with aggravated robbery, wounding with intent, unlawful taking of a motor vehicle and several driving offences, Mr Begbie said.
He has been remanded in custody to appear in the Whangarei District Court on September 1.
Investigations into the second teen are on-going, Mr Begbie said.
It was a "very traumatic incident" for the elderly woman, he said.
"It is pleasing that our staff were able to catch an offender reasonably quickly after the incident.
"We are also following up strong leads to locate the outstanding offender."