Robin Bain had arranged to be at a meeting to get help for his school on the morning he and four of his family were killed, a court has heard.

The High Court in Christchurch also heard today that a psychologist who had known Robin for many years will describe him as being clinically depressed at the time of the deaths.

Robin, 58, was found dead, along with his wife, Margaret, and three of his children, in their Dunedin family home on June 20, 1994.

His son, David Bain, 37, is on trial for the murdering the family. But his defence team are arguing that Robin shot the family and then turned the rifle on himself.

Robin has previously been described by several friends and colleagues as a loving and gentle father and school principal, but the defence say Robin's mental health had been deteriorating in the wake of a split from his wife.

Ingrid Dunckley, a psychologist working with troubled children for the Ministry of Education, told the court today that Robin Bain telephoned her on June 17, 1994, in relation to money available for teacher aides at Taieri Beach School, where Robin was principal.

She said Robin arranged to bring collated information about his pupils to her on the morning of June 20. He did not turn up, and Ms Dunckley said she got a call from the school informing her about his death.

Questioned by defence lawyer, Michael Reed QC, Ms Dunckley agreed she worked with a psychologist, Cyril Wilden, who knew Robin for many years and was part of a trauma team at the school after Robin's death.

Mr Reed said: "Mr Wilden will say that he formed the view that Robin Bain was clinically depressed, with a form of reactive depression, in which at times he was flat and lifeless, awkward and difficult to communicate with."

She said the possibility of Robin being depressed was not raised by Mr Wilden until after the deaths.

"He seemed surprised about the discussion of depression. That's what I remember."

Asked if she was aware about Mr Wilden's concerns that Robin get treatment for depression, she said: "I'm just surprised he had concerns and he hadn't mentioned them".

She told Mr Reed she was not aware that Margaret Bain had made a "special appointment" to go and see Mr Wilden not long before the family deaths. She said she had never met Robin or his family.

Ms Dunckley said it would not have been the role of an educational psychologist who worked with children to make such a diagnosis. But Mr Reed put it to Ms Dunckley that Mr Wilden was acting as a friend of Robin's in giving this view.

Ms Dunckley said Mr Wilden became more emotionally involved at the school after the Bain deaths than she would have,

Mr Reed also raised the issue of stories written by children at Taieri Beach School, and sent home to parents, in which parents were shot and stabbed. One child wrote of finding her mother with a knife "stuck through her heart".

The defence say Robin edited these stories before they were sent out to the childrens' parents.

Ms Dunckley said she viewed the stories and did not see the link between these and the killing of the Bain family.

"Children write all sorts of stories and it depends on the context of the classroom, what the topic was at the time."

Earlier today, a witness gave evidence that her father was on the jury when David Bain was first tried for murder of his family in 1995. Bain was convicted, but his conviction was quashed and a retrial ordered in 2007 by the Privy Council.

Asked by prosecutor Kieran Raftery if this family link had anything to do with evidence she gave, the witness said: "Absolutely not. None whatsoever".

Her evidence related to the relationships between David Bain and his family.