Two years since Upper Hutt woman Lois Tolley was murdered, police say they are closing in on her killers.
On December 9 2016, four people violently smashed their way into 30-year-old Ms Tolley's Ward Street home and shot her "execution-style".
Detective Senior Sergeant Glenn Barnett said police had spoken to associates of the four and know who they are.
"They have told us that they know what happened and who the attackers are."
"While some of these associates are unwilling to provide formal statements, there are some who have provided formal statements, allowing us to build a solid group of witnesses who are signed up to give evidence when we're able to bring the case to court."
Mr Barnett said police believe it was a targeted, drug-related attack.
"Sadly, Lois had become involved in the Upper Hutt drug scene and her death appears to have been connected to that world.
"We believe that the four people who came to her home that night were attempting to carry out some form of 'taxing' or debt collection, or that they were looking for drugs and or cash for their own use."
He said police had spoken to hundreds of people.
"As is typical with investigations of this nature, as time passes, the same names keep coming up, while others become less important to the inquiry or are eliminated altogether."
"Lois was no threat to anyone, and even the most hardened criminals and gang members have said her death was a cowardly act and completely unnecessary," Mr Barnett said.
Ms Tolley's mother Cathrine said they were a tight-knit family and her death was devastating.
"It is two years and it just feels like yesterday... I just want to put my arms around her and never let her go."
"They stole her future away from her and have devastated ours. It is so hard not hearing her voice and seeing her beautiful smile.
"We know that Loie was not perfect - nobody is - but Loie was perfect to us."
Mr Barnett said police were committed to bringing the attackers to trial and urged people to come forward.
"There are a number of people who are nervous about speaking to police or providing us with a formal statement, for any number of reasons ... to those people, I would urge them look past their nerves or antipathy to police."
"Put yourselves in their shoes - how would you feel if one of your loved ones died in the callous, senseless way that Lois did, and nobody was brought to justice for it because of some misguided loyalty or a dislike for Police?"
Detective Inspector Scott Miller said a lot of investigative work was being done in conjunction with Australian police.
"A number of people of interest went overseas either soon after the murder, or after they were spoken to by police."
"A number of those people have been spoken to by Australian police, and members of the Operation Archer investigation team have travelled overseas for interviews and some very interesting information has been gained as a result of these overseas enquiries."
"All those involved should know that it is only a matter of time before we knock on their door."