Key evidence for the day
• A police intelligence analyst said more than 400km of travel was unaccounted for in the nine days before the deaths of Christine and Amber Lundy
• Some of that unaccounted travel could be explained by a road test by a mechanic and social driving by the Lundys
• Lundy drove an average speed of just over 100km/h between Johnsonville and Palmerston North on the day the bodies of his wife and daughter were found
• It was difficult to siphon petrol from the type of vehicle Lundy drove because of a metal flap covering the fuel tank, but it was possible if a welding wire was used to hold the flap back
• Police drove a similar vehicle hard and at speeds reaching 140km/h, but accepted they could not recreate exactly Lundy's trip
A police expert is defending her analysis of the distances Mark Lundy travelled in the days before his wife and daughter were murdered in their Palmerston North home.
Christine Lundy, 56, and her 7-year-old daughter Amber were found bludgeoned to death by a tomahawk or similar weapon on August 30, 2000.
The Crown has alleged Lundy drove in his Ford Fairmont EL to Palmerston North from Petone, Lower Hutt, in the early hours of that morning to commit the crimes, which he denies.
In the High Court at Wellington today, police intelligence analyst Mary Ellwood said more than 400km of travel in Lundy's car was unaccounted for in the days before the murders.
Between August 21 and August 30, Lundy travelled 1270km.
But based on information Lundy gave about where he had travelled, Ms Ellwood said he travelled 847km - 423km short of the actual distance travelled.
During that period there were days including weekends, where there was unknown travel, she said.
During cross examination, defence lawyer Julie-Anne Kincade said the unknown travel could have been made up of a mechanic driving the vehicle for up to 15km, weekend travel and social reasons.
There was also unknown travel around New Plymouth, where he went on a business trip.
Ms Ellwood accepted her analysis was based on routes that were shorter than Lundy could have driven.
Ms Kincade said the unknown travel time was "meaningless", but Ms Ellwood refuted that, saying the distance of unknown travel was significant.
On the day his car was seized, Lundy received a call on his his cellphone that placed him on the Johnsonville motorway. He arrived at Palmerston North nearly an hour and a half later, when his car was seized.
Ms Ellwood said at that time, his fuel tank was almost empty and she calculated that he had been driving an average of 100.48km/h between the two locations.
Also giving evidence today was former police officer Marie Lambeth, who described travelling with Mrs Lundy's brother James Weggery back to the police station after securing Lundy's car outside the Lundy home.
She confirmed Weggery was wearing street clothes and not protective clothing. Nor, to the best of her knowledge had he changed his clothes, Ms Lambeth said.
The court also heard evidence from Courtesy Ford employee Gareth Townend who said it was "extremely difficult", but not impossible to siphon petrol from the type of vehicle Lundy drove.
Ms Kincade said Lundy had claimed petrol could have been siphoned from the vehicle on the night of the murders.
Mr Townend said a springloaded metal flap in the vehicle would stop a hose from gaining access to the petrol.
But it would be possible to extract the petrol with a hose if something like a piece of welding wire was used to hold the flap back.
Earlier today, Sergeant Danny Johanson described three round trips he took between Palmerston North and Petone in an effort to recreate the journey taken by Lundy.
He said he drove the car "hard" and at speeds reaching 140km/h but accepted there was no way he could exactly recreate the journey because there were too many variables.
"It was hardly a scientific experiment," Mr Johanson said.
The trial in front of Justice Simon France and a jury of five women and seven men continues.