A 17-year-old girl has been arrested in relation to the brutal car jacking in Panmure that hospitalised an elderly woman last week.
Two other suspects, under the age of 17, have been "identified," said a police spokeswoman.
The teen has been charged with aggravated robbery, theft and two charges of unlawfully taking a motor-vehicle, and will appear in the Auckland District Court this afternoon.
The two others are currently in CYFS custody on an unrelated matter and police are in the process of arranging to speak with them.
"Both are under the age of 17 and we are therefore limited to any further discussion on this aspect, but we can advise that we are not looking for anyone else in relation to this incident."
Nancy Voon, 65, was allegedly attacked while waiting for her son outside the Panmure YMCA around midday Thursday.
"We have advised the family of the victim of this development a short time ago, and they are understandably relieved to hear this news," said the police spokeswoman
She thanked "the hundreds of people" who helped with the police investigation.
"The public and media assistance we received has got us to this point," she said.
"We had dozens of calls with information, as well as many private messages to our Facebook page. Hundreds of people shared the link to the Facebook video, and this in turn ensured that as many people as possible saw the CCTV footage."