The jury in the retrial of murder-accused David Bain has heard crucial evidence about a computer at the house where his family was killed.
The Crown says David Bain, 36, killed his parents Robin and Margaret and siblings Arawa, Laniet and Stephen at the family's house in Every Street, Dunedin, on 20 June 1994.
The defence says Robin Bain killed the family present in the house before shooting himself.
The Crown continued its case in the High Court at Christchurch on Thursday.
Inside the Bain family home where five people lay dead there was an unsaved message on the computer: "Sorry you are the only one who deserved to stay".
The Crown says David Bain typed the message as part of his plan to frame Robin Bain for the murders.
The defence argues that David Bain was still on his paper round when the computer was switched on and that it was Robin Bain who typed the message.
Martin Cox, who analysed the computer in 1994, told the court in David Bain's original trial that the computer had been turned on at 6.44am on the day of the killings.
But the court heard on Thursday that the timing was based on a detective's watch, which was up to two minutes fast.
At Mr Bain's first trial in 1995, Mr Cox provided the court with an estimate of when the Bain family computer was turned on. That evidence was not tested or disputed by the defence at the time.
On Thursday, when cross-examined on computer evidence linking Mr Bain to the deaths, Mr Cox conceded that the machine could have been turned on earlier.
Mr Cox told the court he knew when he started using the computer that his task would be difficult.
He said that in 1994 the computer would have been about 10 years old and told Crown prosecutor Kieran Raftery that he noticed there was no accurate time or date on the machine.
He said he saved the message and then tried to establish what time the computer had been switched on.
The defence says the disputed time of 6.44am shows there is doubt about whether David Bain had time to type the message on the computer after returning from his paper round.
Defence lawyer Michael Reed, QC, suggested Mr Cox knew that the time estimate might be wrong, but did not make the first jury aware of that.
Mr Cox replied that 6.44am was his estimate of when the computer had been switched on.
Ammunition found in Bain's wardrobe
Earlier, the court was told the accused's wardrobe contained more than 20 boxes of live ammunition and a home-made target.
The Crown says David Bain killed the family with a rifle he owned. However, the defence says Robin Bain used his son's gun to commit the murders, then kill himself.
Kevin Anderson was one of the officers who examined David Bain's bedroom after the killings and told the court on Thursday he found more than 20 boxes of ammunition in the wardrobe. Most were full and the type of ammunition varied.
Mr Anderson also produced a receipt as an exhibit which showed David Bain purchased the rifle in February, a year before the killings.
On Wednesday, another officer produced an exhibit that was a large piece of cardboard with five red circles drawn on it found beside David Bain's wardrobe.
Mr Anderson also testified on Thursday about finding and examining that exhibit which he referred to as a target.
Blood spots on underside of duvet
The jury was also told blood spots were discovered on the underside of David Bain's duvet after the family were killed. Mr Anderson said he did not record exactly how many there were.
On the day of the killings, David Bain told police he came home from his paper run and found his parents dead. He said he did not touch them or go into any of the other bedrooms, where his brother and sisters had also been shot.
Blood spots were also noted where the body of Robin Bain was found on curtains that separated an alcove housing the computer.
Mr Anderson said he noticed the coffee table had been moved and that the room was cluttered and untidy.
