Kaitaia police have arrested two women over the knifepoint robbery of a local bakery.
Senior Sergeant Geoff Ryan said the the women's families took the pair in to the station on Thursday morning after the police posted video footage of Sunday's robbery on Facebook.
They were immediately swamped with replies from people who saw the footage and who all came up with the same names.
"Really well done to the Kaitaia community. They've stood up and made a very clear statement to the rest of the community about what they're willing to accept and what they're not," Mr Ryan said.
"We had so many responses to the Facebook page that we actually had to take it down off the site because we had so much information coming in."
Facebook was proving to be a useful crime-solving tool for police in the north as it was used every day by many people who did not use other media.
An 18-year-old woman has been charged with aggravated robbery and a 21-year-old with receiving stolen property.