Police were also still seeking the knife and firearm believed to have been used in the attack and continued to seek information on the four men seen heading for Tolley's Ward home shortly before midnight on Friday December 9.
The men are described as aged in their 20s and were wearing dark, hooded clothing.
Police had also identified other "persons of interest" who they would be speaking to, Barnett said.
Witnesses spoken to by police had provided good information.
"As I've said previously, we do believe the people who committed this violent attack were known to Ms Tolley, and someone out there will know who is responsible," Barnett said.
"For the sake of Lois' family, I would ask again that anyone with information that may assist the investigation get in touch with Hutt Valley Police."
Information can also be provided anonymously by calling Crimestoppers on 0800 555 111."