One year on from Lois Tolley's murder, police have narrowed the suspect list to 12.
They were either directly involved in committing the murder, helped plan the attack on Tolley, or assisted the killers after the murder, on December 9 last year.
The police investigation team has worked through more than 130 people of interest to get to this point.
Detective Senior Sergeant Glenn Barnett said that despite the time passed, the investigation team was absolutely confident arrests would be made and the people responsible for Tolley's death would be held accountable.
"Although there have been no quick arrests, police and the investigation team of approximately 12 staff are still fully committed to solving this murder.
"A large amount of evidence has been collected to build up a full picture of events on the night of Friday 9 December 2016.
"We are also gaining an increasing amount of direct or first-hand evidence needed to put this matter before the court."
The list of 12 includes both men and women, some of whom were known to Tolley.
Barnett said they had spoken to 15 people who had direct knowledge of the killing but until this point they had refused to assist police to progress with the investigation.
"Those people have got families. Those people are aware of the hurt that the Tolleys are going through. They've thought about what knowledge they've gained . . . they've come and spoken to us."
Some had also spoken after being approached by police a few times.
"We are seeing this attitude slowly changing with a number of people starting to come forward with valuable information, and we thank them for their assistance. However, we still need more of the people, who have spoken with the offenders, to contact us.
"There are people in our community who are close to the Tolley family who still haven't spoken with Police."
Barnett urged those people to come forward.
"Where there's evidence that they've covered up or they've protected what these killers have done, they will face charges in court . . . [there's] an opportunity now for them to come forward."
Police could not put a timeframe on when an arrest was expected.
"Everything that we do will get examined in the High Court, so we've got to be 100 per cent sure that the evidence . . . links to the people involved.
"It's going to come under a test in a High Court trial and we've got to make sure that it stands up to that test."
While people had told police information about who planned the attack, Barnett would not say what reasons were given for why Tolley was killed.
He said police were not aware of Tolley being involved in drug dealing.
Tolley's family commemorated her life in October, 10 months after the murder. Tolley's mum Cathrine and over 50 friends released 100 balloons in an Upper Hutt park to remember her.
The close group, mainly from the Upper Hutt community, reflected, told stories and shared memories of a young woman's life cut short in a few terrifying moments inside her own home.
The meeting of friends and family was an extremely emotional time for Cathrine and family who attended knowing that the one-year anniversary of Tolley's death was approaching.
MacDonald told police how the killing had devastated their family.
"Words cannot describe how we all feel, it feels like just yesterday that these cowards took her from us, the pain does not get any easier.
"We miss Lois so much, this has devastated our family and her friends, they stole her future from her and all of us."
MacDonald, has a message for the killers: "The police know who you are."
"All I can say is they will be caught," she told the Herald. "The police have no doubt about that and [neither] do we."
Police confirmed earlier this year that at least four people were involved in the homicide, which happened just after midnight on December 9 last year.
A group of four males were captured on CCTV camera fleeing the scene.
As the attackers escaped, one of them was heard swearing and yelling, "Oh my God, what have we done?"
A neighbour in the block of flats next to Tolley's found her body. She had heard Tolley screaming.
The neighbours have been trying to find somewhere new to live since then but haven't had any luck.
This week, describing that night and what life has been like for her in the year since, the word she keeps repeating is "traumatising".
Wellington Police are asking for anyone who has not previously spoken with police, but who may have new or extra information that would assist the homicide investigation to contact them immediately.
They can contact Police by ringing (04) 381 2000 or by private messaging the Wellington Police Facebook page.
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