A Chinese woman who killed her husband and tried to kill her daughter-in-law will not be deported when she has served her jail sentence.
Guan Zhi Yu stabbed her son's wife with a knife at their home in Nelson and fatally stabbed her husband when he tried to stop her.
The 62-year-old is serving a five-and-a-half year sentence for manslaughter and attempted murder at the secure psychiatric hospital in Christchurch.
The Immigration and Protection Tribunal said sending her back to China would exacerbate Yu's vulnerability to her mental illness and aggravate the tragedy already experienced by her son.
He lives with his son, and his wife has since moved to China with their daughter.
The sentencing judge outlined the attacks which happened when Yu's daughter-in-law returned from a trip to China. During this time Yu had been caring for their baby and a pre-schooler.
"You were very unhappy about her return. You made inquiries about arranging a divorce for your son. You searched for a new wife for him on an internet dating service.
"You walked into your daughter-in-law's bedroom armed with one or two knives. Your husband, your daughter-in-law and your grandchildren were all in that room.
"You stabbed your daughter-in-law in the chest. She fled the room. Outside she called 111 on her mobile phone.
"It appears your husband tried to disarm you. You bit him on the left forearm, then stabbed him once in the left-hand side of his chest with the other knife.
"The wound was eight to 10cm deep. You punctured his lung and cut through the main artery and vein to his left lung.
"It seems your grandchildren were also present throughout the attack. Your husband was holding the baby when you attacked your daughter-in-law."
The tribunal heard if that if Yu, a former teacher, returned to China she would not receive the support she would get in New Zealand when she was released.
Her lawyer argued she may be liable for prosecution again in China for the same offences of which she had already been convicted.
Counsel for the Immigration Minister told the tribunal mental health services were available in China and the woman, who moved to New Zealand with her husband in 2012, had siblings and accommodation to return to.
Immigration argued there was an "unacceptably high" risk of her reoffending, and also pointed to the expense of maintaining her current level of care.
It said there was no reason her son and grandson could not return with her, which would also promote the family's unity as his daughter now lives there.
But the tribunal said it was satisfied that if she remained in New Zealand: "the risk of her becoming so unwell that she offends again in similar manner is low".
"There is no reason to believe that she provides any risk of reoffending when she is well."
It suspended her deportation liability for five years, on the condition she does not commit any violent offence in that time.