Two people were killed in stabbings on Saturday evening.
The first incident happened on Ilam Rd in Christchurch. Police were called to the scene at 7:50pm, where they found a man and a woman had been stabbed by another man. The woman, 28, was killed.
The suspect, 52, then turned the knife on himself. He and the 31-year-old man he allegedly stabbed remain in Christchurch Hospital, both in a serious condition.
"Those involved were all known to each other and police are not seeking anyone else," said Det Snr Sgt Scott Anderson.
The suspect has been charged with murder and wounding with intent to cause grievous bodily harm.
Later that evening around 8:45pm, police were called to an address in Moerewa in the far north. There they found 57-year-old man in a critical condition after being stabbed - he died a short time later.
Police have launched a homicide investigation, saying the alleged stabber is known to the victim. They say a woman is helping with inquiries and no one else is being sought in relation to the death.