Raurimu massacre gunman Stephen Anderson - whose six victims included his father - is set to publish a book revealing the “untold story” of his “heinous” crime.

And ahead of the publication of The Devil’s Haircut, Anderson has said he is “very sorry” for what he did.

In February 1997, Anderson shot and killed six people at and around his family’s holiday home in Raurimu.

Several others were injured by his gunfire but survived to give chilling accounts of his actions.

Anderson was later charged with six counts of murder and attempted murder of eight people. But in late 1997, in the Hamilton High Court, he was found not guilty by reason of insanity and detained indefinitely at a forensic mental health unit at Porirua Hospital.

Since his release more than a decade later, he has published a book of poetry and become an artist.

“What happened at Raurimu was heinous, and I am very sorry for the part I played, and the actions I took,” Anderson said in a press release promoting his new book.

Police and forensic staff remove a body from the bushes on the Van De Wetering driveway. Photo / File

“Some people feel I have ‘gotten away’ with what I did. But while the consequences have been numerous, varied, and in large part irreversible, it would appear that important lessons from the tragic events at Raurimu have not been so obvious or necessarily made apparent to people who should know.”

In the release promoting The Devil’s Haircut, it says the book is “the untold story” and written in a way that “only Steve can tell it”.

“Steve Anderson was 24 when he killed his father, Neville, and five other everyday New Zealanders friendly to his family, in and around the Anderson family’s ski and hunting lodge at Raurimu, a small hamlet, nestled not far from National Park and Mt. Ruapehu in the central North Island Manawatu district,” the release said.

“Four other people received gunshot injuries, and they, the families involved, and many others who dealt with the aftermath, live today with deep psychological scars.

“At his December 1997 High Court trial Steve was found not guilty by reason of insanity, and Steve’s father was heavily criticised by coronial proceedings in the wake of his own and the others’ deaths.”

Said Anderson: “Every pancake has two sides, no matter how thin.

The ski lodge at Raurimu, where Stephen Anderson went on a killing rampage in 1997, killing six. Photo / Mark Mitchell

“The coverage used to assist the public to make sense of the Raurimu tragedy was all either a little too convenient, or a rather poor fit.

“Mental health in this country has lurched from crisis to crisis for decades. And with the various inquiries, reports, cash injections, and the persistent claims of wonderful advances in modern psychiatric drugs, you would think we’d all be starting to find some peace of mind, by now.”

Anderson had been diagnosed with mental health problems prior to the massacre.

In the aftermath of his actions, his family faced criticism for him being able to have access to his father’s firearms at the ski lodge.

The group who had been staying at the lodge that fatal weekend included family friends of the Andersons, and work colleagues.

The book’s promotional blurb said “According to the multidisciplinary Dunedin study, at some point in our lifetime, 83 per cent of people will experience a psychiatrically diagnosable period of human distress.

“This makes The Devil’s Haircut a timely book with something to offer everyone, because, if it is not us, it will be someone we know and care about who is struggling with their mental health.”

The scene of the Raurimu massacre - the lodge owned by Neville and Helen Anderson - after the fatal shootings. New Zealand Herald photograph by Mark Mitchell

It added that Anderson’s experience of treatment had made him feel “compelled” to write the book”.

Anderson added: “My intention is to help both myself and others heal, rather than cause further harm to anyone.

“I pass on the uncommon knowledge I have gained over years of effort during my detention and treatment as a high profile ‘special patient’. My book describes the hidden process behind my decompensation, offending, and recovery, which has not been as many may have expected or imagined.

“I hope The Devil’s Haircut will help others understand, or make further progress in their own walk, whatever that might be.”

The book is set to be published next month.

The blurb adds: “In a rarely candid, conversational style, the story told in The Devil’s Haircut makes Steve’s thoughts, actions and ideas almost tangible. We accompany him as he made his decisions through this experience.

“This memoir is a story worthy of being heard. Steve’s years of inpatient forensic unit detention and eventual reintegration with the community has taught him much about the workings of his and others’ minds.”

Anderson had been diagnosed with paranoid schizophrenia in 1995.

At the time of the massacre, he was under the care of the Capital & Coast District Health Board.

On the weekend of the massacre, his parents felt he was not well enough to be left home alone in Wellington; a decision that would end up costing six lives, and leaving survivors with mental scars that will never heal.

The memorial at Raurimu to those who Stephen Anderson killed. Photo / Mark Mitchell

Anderson’s mother, Helen Anderson, said during the latter High Court trial: “He just came into the room with quite a stern look on his face, then he said something about having had sex with a cat and dog.

“I was quite horrified. I got up immediately and suggested he go into the bathroom and have a wash, then go and have some breakfast.”

Anderson would return to the group who were gathered downstairs in the lodge; but this time with a shotgun.

“What are you doing ... Give it to me Stephen,” Neville Anderson shouted at his son, grabbing the barrel of the gun.

Anderson pulled the trigger and killed his father.

Tragically, five more were to be killed by Anderson.