It comes as figures released to the Herald under the Official Information Act show there are more than 2000 assaults on police officers a year.
Figures for the 2010/2011 year, the most recent data available, showed officers were "manually" assaulted - attacks without weapons - more than 1800 times.
There were also a dozen charges involving firearms.
Police Association president Greg O'Connor said: "It's just a little message to criminals that society does take this seriously, and that we're talking about more than an assault on officer ... it's an assault on society."
Further figures show there were 150 assaults on ambulance officers in the past four years, including 16 so far this year.
A St John Ambulance spokesperson said officers were well-trained when it came to personal safety and made allowances for emotional patients and bystanders, but any kind of assault was unacceptable.
New Zealand Fire Service assistant national commander Paul McGill said the change reflected public concern. No assault figures were available.
"It may be that there is some safety in numbers - each appliance is crewed by four firefighters and often more than one appliance responds to an incident."