Phillips died after a shootout with police yesterday.
Victoria University of Wellington senior supervising clinical psychologist Dr Dougal Sutherland said nothing like that had happened in New Zealand before, so it would be challenging for clinical psychologists to tackle the impact it had had on the children.
"As far as I’m aware, this is a new situation for New Zealand, particularly when it has been a parent that has taken children, rather than a stranger."
The children — Jayda, 12, Maverick, 10, and Ember, 9 — had spent the past four years growing up in isolation, hidden away from friends, family and the community by their father.
Reintegrating them back into society would be "very difficult", Dr Sutherland said.
"Their world has been centred around their dad and living in the bush for four years, so going back to mainstream society will be a massive adjustment.
"They are likely to need support in education, in learning how to socialise with other children, in re-establishing a relationship with their mum and other family, in grieving for their dad and returning to live in a society which they may have some deep suspicions about."
Without meeting them, it would be difficult to say what social or psychological behaviours they might exhibit, he said.
"It will also be affected by the different ages they are.
"Obviously, they will be grieving about the loss of their dad, they may be frightened, confused and anxious about returning to ‘normal life’, they may be very mistrustful of society — this could show up as behavioural difficulties, withdrawal, anxiety."
He believed it could take many months, or possibly years, for them to recover.
