The intruders had demanded property and cash before searching the house and stealing personal items. They then left in a vehicle, possibly toward Lincoln Rd, Bysouth said.
He said the robbery was a "targeted attack" aimed specifically at stealing cash and electrical items from the victim.
"Police do not believe there is any risk from this group to the wider community at this time.
"The homeowner has experienced a terrifying ordeal and while not physically harmed, has been left extremely shaken."
The victim had been referred to Victim Support. Police were investigating and following positive leads to help identify those involved.
Carterton mayor Greg Lang said he had recently been updated by the police Area Commander about the incident.
"All I know is it's gang-related and there's a firearm involved," he said.
He said the perpetrators were believed to be from out of town.
"It's just not normal to have this sort of thing happen in Carterton."
He echoed one of his councillors expressing the sentiment: "go away yucky people, we don't want you in our community."
Police say the four offenders were all wearing dark clothing and bandannas over their lower faces. They were described as:
*One person who was stocky and tall;
*One was tall and slim
*One was small and thin
*A fourth person could not be described apart from wearing dark clothing
The firearm was described as long-barrelled and was likely to be a shotgun or rifle of some description, Bysouth said.
Anyone who saw a vehicle in Frederick St between 1.30am and 2am on Saturday should contact the Wairarapa Police on 105 and quote file number 200613/1775. Alternatively contact Crimestoppers anonymously via 0800 555 111.
