In 1963, four New Zealand police officers and the owner of a dog kennel were fatally shot in two shocking events.
The killings rapidly led police to upgrade their own protection - and take measures to better protect the public. The result, in August 1964, was the creation of the armed offenders squad (AOS).
This week, the unit celebrates its 50th anniversary.
Equipped with the latest and best technology, the squad has come a long way from the berets and pistols which marked its launch.
"In the early 60s we were one of the first forces [internationally] to do this," said Detective Superintendent Ray van Beynen, a former 19-year AOS veteran and current deputy director of the police Organised and Financial Crime Agency of NZ (Ofcanz).
"[And now] our specialist teams are very highly regarded. I have had the chance to look at tactical teams in the United States, Germany, the Dutch, the Brits and the Australians, and in my view we are amongst the best in the world.
And we should be really proud of that."
The twin catalysts for the establishment of the AOS were two shootings within a month of one another in early 1963.
On January 6 of that year, a mentally disturbed man opened fire on people at boarding kennels on Bethells Rd in Waitakere, killing kennel owner James Berry and wounding a customer. Two of the first officers on the scene, Detective Inspector Wallace Chalmers and Detective Sergeant Neville Power, were also shot and killed.
Then, on February 3, Constables Bryan Schultz and James Richardson were gunned down in Alicetown in the Hutt Valley, after being called to a domestic incident. The gunman fired on them from the Herbert St house, killing both before they even turned the engine off in the squad car.
A subsequent review led to the recommendation that a special police squad be formed to deal with armed offenders.
A team of specially selected cops were brought together and trained by the army in Papakura in South Auckland, from August 3-14.
The unit has continually progressed its methods and equipment since - although the Aramoana massacre, in particular, helped create the modern iteration of the team.
"That was probably the watershed moment," Mr van Beynen said. "There was a realisation that we needed to modernise."
Over the years the number of AOS callouts has increased dramatically from a handful a year in the 1960s to 746 recorded this past financial year.
Now there are 17 AOS teams across the country, made up of almost 300 police volunteers. And for police and civilian alike, this has been a blessing, Mr van Beynen said.
"There's a bit of reassurance in having a highly-trained, highly-skilled group available.
"When risk is of a significant level - incidents like clandestine drug labs, people that have been using drugs, gang members and the execution of high-risk warrants - the AOS will be called."