Police in Palmerston North say they are still seeking vital information as they put together their case against Mark Lundy, who is charged with the murder of his wife and daughter.
The battered bodies of Christine and Amber Lundy were found in their home last August.
Detective Sergeant Mark Painter says police would like help from the public to map Mark Lundy's movements on the night of the killings.
He believes Lundy drove at speed from Petone to Palmerston North and back again, and are interested in any sightings of his blue Ford Fairmont car.
They are also still looking for a missing jewelry box, a tomahawk, and clothes they believe Lundy was wearing.
On Friday, Lundy was taken to court to face two counts of murder. There was no plea and he was remanded in custody until Thursday next week.
On the morning of August 30 last year, Christine's brother found her and her seven-year-old daughter Amber dead in a bedroom in their Kelvin Grove home.
They had been viciously killed with what police think was a small axe, but the weapon has never been found.
Police had to use dental records to identify Christine and Amber.
A 40-strong team has worked on Operation Winter, the biggest murder hunt police have ever launched in Palmerston North.
They have spent over 20,000 hours working on the case and interviewed over 2,000 people.
So far the investigation has cost more than $100,000.
Seven days after their bodies were found, Christine's family made a plea, saying: "At least one of our community knows who killed two people who were very much loved - their life must be a living hell."
The following day Mark Lundy buried his family.
Police took Mark Lundy into custody on Friday afternoon after interviewing him that morning.
The arrest follows vital new evidence from forensic scientists at the Institute of Environmental Science Research, but police are still seeking more evidence for the case.
The Palmerston North community has expressed both shock and relief at news of the arrest.
Mark Lundy ran a kitchen sink business with his wife and was involved in the theatre society and the Scout and Guide movement, where he met his wife Christine.
He is now behind bars in Manawatu Prison.