"In the past 10 years, there's been a big escalation in the number of people in the street prepared to have a go at police officers."
Mr Shadbolt believed policing was becoming a more dangerous profession as a result.
"Police are dealing with a lot more unpredictable behaviour than they used to -- drug use and mental health issues factor in that.
"Officers are generally able to talk to people in the first instance, but in some cases, especially those affected by alcohol and drugs, situations can evolve very quickly."
The association was pleased access to tasers and firearms, and police training had improved -- but believed more could be done to protect officers, he said.
"It's extremely unlikely for an officer to go through their career without being assaulted. We need to keep pushing safety and training, and getting new and better equipment.
"Tasers in particular are very good in escalating situations but there's rules about when you can carry them. [The association] thinks there should be a change in policy to allow officers to carry them at all times."
Assistant Police Commissioner Mike Rusbatch said the safety of staff was taken seriously.
"[Police] work very hard to ensure they are well trained, equipped and supported to carry out their jobs," he said.
"In recent years, this has included the roll-out of improved tactical training, the introduction of stab resistant body armour, greater access to tactical options such as Taser and firearms, and the introduction of officer safety alarms for those working in remote areas."
Any violence or assault on staff was "unacceptable", however, he said.
"Tactical training is also heavily focused on officers using their judgement and the de-escalation of violent situations with force that is appropriate to the situation. This means the vast majority of incidents are resolved peacefully.
"We also continue to review critical incidents to ensure our tactical responses remain in line with best practice and to identify any lessons that can help us ensure our staff and the public continue to be kept safe."
Assaults on police
2004- 1944
2005- 1911
2006- 2149
2007- 2340
2008- 2364
2009- 2574
2010- 2198
2011- 2015
2012- 1812
2013- 1629
2014- 1614
Source: NZ Police