Police in the North Island have launched 10 homicide inquiries in a little over a month.
Half of the homicide investigations since the beginning of August were in Auckland.
The rest were all in the North Island.
During a press conference on Friday about the Grey Lynn homicide, Detective Inspector Glenn Baldwin said it was the fourth homicide investigation police had launched in the last 10 days.
"None of these incidents appear to be linked, they're all separate," Baldwin said.
"It is a tragedy, the timing is incredibly unfortunate, but we are investigating all of those matters with diligence. Those other three matters, the offenders have been arrested and those matters are now before the courts.
"This matter has our absolute focus at this time. We will work hard over the next few days to understand the circumstances, we are following positive lines of inquiry and ... we are focussed on holding this offender to account."
Homicide investigations since 1 August:
- A man was killed and three injured after shooting in Grey Lynn, Auckland on Thursday;
- An 8-year-old boy who was killed in Hamilton was allegedly attacked with a hammer while he and his father slept in bed. He died in hospital on 1 September;
- Anthony Edward Rangi, 50, was killed after shots were fired in Onehunga on 31 August. A 32-year-old man appeared in court on Monday charged with murder;
- A man died after being stabbed in the Auckland suburb of Mount Wellington the afternoon of 31 August. Two people were arrested;
- Stephen Thorpe, 54, was found stabbed on 24 August in Blockhouse Bay, West Auckland. A man was charged with murder and was due to appear in court;
- A 34-year-old man has appeared in court this week after the death of a 60-year-old man during a family harm incident in Pātea on 24 August;
- Saia Kokohu Vi, named by police as Tuipulotu Vi, was shot on 19 August outside his family home in Pakuranga;
- Two people were found dead at a property in Tūrangi on 15 August. A homicide investigation was launched. Police later said they did not believe anyone else was involved and referred the matter to the coroner;
- A 50-year-old man has been charged with murder after a 51-year-old who died after being found seriously injured on the side of a Northland highway. He was found seriously injured on the side of State Highway 12 on 1 August and died at the scene;
- Joanna Mai Sione-Lauaki, 38, was reported missing on the morning of 2 August after she failed to return home the night before. She was discovered later that day by a member of the public on Ripiro Beach, on the west coast, north of Dargaville.
Police were also investigating the death of Steven Cranston near Raglan on Wednesday. He died after apparently being struck by a vehicle while walking his dog. It is not yet a formal homicide inquiry.
An investigations is also under way into an unexplained death in Oxford, North Canterbury.
In a statement on Friday, a police spokesperson said they acknowledged the "unusually high number of homicides" over the past few weeks.
"In general, police and other agencies look at data from longer periods of time to establish any significant trends that might give insight into the full picture of what is occurring."
Police were confident they had adequate resources to investigate each case, the spokesperson said.
"Our staff work tirelessly to bring these offenders before the courts to be held accountable.
"We note that of the 10 homicide investigations launched between 1 August and today, people have already been put before the courts in six cases."