When asked how many times she was stabbed, Bernett said police were waiting for the post-mortem examination results.
Barnett said police were still looking for four men and for the weapons used on Tolley.
He said police had gathered evidence they hoped would identify her killers.
He said there were "persons of interest" but would not comment on how close they are to making an arrest.
"The people responsible for this killing [will] be waking each morning thinking, is this the day that NZ Police are going to knock on their door and take them into custody."
He pleaded with anyone who was involved, if they weren't one of "the main culprits", to come forward.
"The door is open for those who were there on the night but not a main player to come forward in confidence to us."
A vehicle was possibly involved but police did not have details yet, Barnett said.
At the start of investigation, "persons of interest" were arrested on unrelated matters, but the people responsible for the murder had not been found.
"We've worked through those people we've arrested, we've cleared what we need to clear with them, and we move on to the next stage," Barnett said.
He would not confirm if drugs were involved and said police were "open-minded" about why Tolley was targeted.
He said it was not a random attack.
"It's a tragedy, a female being targeted in her own home by four offenders, armed with weapons."
Each day, a team of between 20 and 30 staff were making progess. They were analysing CCTV, forensic material from the scene and speaking to a large number of witnesses and family members.
Tolley's funeral was on Saturday and several members of her family attended from Australia.
"Her family, despite the circumstances, are doing really well. They are supporting the police," Barnett said.
"The stress and sadness of this young woman being confronted and killed by these men in her own home is a horrific experience for any family to endure.
"We thank the Upper Hutt community and the wider community for all the assistance that they've given in this enquiry to date and continue to give today."
Anyone with information is encouraged to contact the Operation Archer team based at Upper Hutt Police Station or by ringing (04) 381 2000 or Crime Stoppers on 0800 555 111.
