Violent criminal behaviour directed at police is ramping up like never before, says the police commissioner.
Video taken at the weekend shows an Auckland police officer on the ground as a man repeatedly swings punches at his head, following a traffic stop on Lincoln Rd.
A 19-year-old man is facing two charges of aggravated assault, wilful damage and interfering with a car.
"Probably most concerning for us [are] the situations we've seen more recently that have involved higher levels of violence, particularly where offenders have been prepared to use firearms towards police.
"What we have seen is an escalation in offenders' willingness to use violence towards police.
"I think there is an increased level of concern from our people about frontline safety.
"Obviously the incident involving the shooting of Matthew Hunt has reverberated through the organisation and it's caused increased concern and awareness about frontline safety."
Coster said it was hard to put a finger on what was behind this increase, "but generally speaking, [these situations involve] offenders who are not making sound decisions that a sober person would make".
"The sort of high-risk taking behaviour by offenders is a step up from what we've seen in the past.
"It is to some extent linked to gang activity, but that particular incident [where a gun was pointed to the head of a member of the public last week] wasn't involving a gang member.
"Whether media and gaming that has seen this kind of behaviour normalised has some part to play in it, I don't know. But I'm hard pushed to explain the extent of the violence, the gratuitous nature of some of the violence that we've seen."
Mental health and drugs were two areas that stood out as driving factors, he said.
Bodycams were also an option that police were considering using, but while they created good evidence, they did not necessarily stop violence, he said.
"It is something we need to bear in mind when we consider these events that we see them more now because they are being recorded by people with cameras, which wasn't a feature of offending 10 years ago, and so it's a lot more striking when you get the footage of it."
He said he did not think recording these incidents would likely lead to a de-escalation in most incidents.
"I accept in some situations that offenders might think twice, but for the most part, when these crimes are committed, offenders are not rationally reasoning through their actions to decide whether they will or won't."
Coster said officers that had completed the primary course as part of the frontline safety improvement programme reported being more confident about how they approach their duties.