Matthew Abraham James Warrington (23), who suffered from autism, is accused of the murder of Vicki Lee Warrington (48) and wounding a man with intent to cause grievous bodily harm on July 3 last year.
He has been ruled unfit to stand trial and appeared before Justice Gerald Nation at a disposition hearing in the High Court at Dunedin this morning.
A psychiatrist's report said Warrington had "exaggerated sensitivity and low self esteem'' and was in a fragile mental state and publication of his name could worsen his mental state and suicide risk.
Justice Nation ordered Warrington be held as a "special patient'' in hospital because of his risk to the public.
He said the man was at no greater risk of suicide now than he had been previously, because of the care and protection he would receive.
He ruled the man would not suffer from extreme hardship if his name was published.
The argument between Warrington and his mother began after Mrs Warrington told him he was no longer welcome in the house and said he had to leave, Justice Nation said.
Warrington the allegedly pushed the victim into the hallway of the house.
While she lay prone, the man kicked and punched the victim about her head and body, the court heard.
He then picked up a small table and repeatedly struck the victim's head and body.
The other man was forcefully pushed backwards and struck on the top of the head with the same table, causing deep lacerations to his skull.
He then took a wooden handle carving knife form the kitchen drawer.
The other man barricaded himself and called police.
The man then stabbed and slashed the woman to her face, neck and torso with the carving knife, causing her death, the court heard.
The defendant had a history of aggressive behaviour and was first spoken to by police for assaulting his mother when he was 12, Justice Nation said.
He had also been cruel to animals, particularly cats and dogs, and was expelled by a number of schools for aggressive behaviour, the court heard.
In 2011, he was deemed not to have any significant mental health disorder.
However, a psychiatrist later diagnosed the man with autism.
He frequently self-harmed, had suicidal thoughts and spoke of killing people, the psychiatrist said.
He had been worried the man was a psychopath.
A psychiatrist said the man could not control himself during the incident.
He was found to have little insight into the seriousness of what he had done after the incident.
