Police officers might be more nuanced than previously thought in deciding whether it's worth stopping people for minor crimes.
A former Kiwi officer spent more than 800 hours shadowing police in South Australia and New Zealand, examining how and why they decide to interact with the public.
Ross Hendy, a researcher with Australia's Monash University, was still a serving New Zealand officer when he carried out his study, joining foot patrols and ride-alongs in two major cities - anonymised in his research.
He's dubbed the process "suspicioning", telling AAP that officers use three steps alone or in combination to decide if a person's behaviour or situation justified an interaction with police.
They consider if the behaviour is harmful, if it's socially acceptable and whether it's legal or illegal.
Dr Hendy's research focused on things observed by police on patrols that fall into a fringe category. They might include jaywalking, public urination or obnoxious drunken behaviour.
The research came out of a desire to understand what would trigger an officer to do something about what they saw and the fact there's little research into policing in Australia or New Zealand.
When identifying harm, one officer said they'd stop if a person was being "wronged", while another said they prioritised by the type of harm.
In one situation they identified a person involved in a nightclub assault but arrived to find a woman having breathing difficulties.
"My attention immediately went to her ... because obviously that's a life and death situation, or could possibly be," the officer said.
But there's also ambiguity in identifying harm, as officers in New Zealand discovered while responding to a neighbour's call about suspected domestic violence.
On arrival they discovered screams heard from the apartment were from sexual activity, rather than physical or emotional harm.
Officers took different approaches when it came to identifying socially acceptable interventions and the bounds of legality versus illegality.
One officer said they wouldn't necessarily intervene if doing so would cause them more embarrassment than the situation justified, suggesting stopping a person skateboarding or crossing the road against a red light.
"You'd probably just bring negative comment upon police for being seen to do something," the officer said.
But their view wasn't universal, with another officer describing themselves as "quite pedantic", saying they would stop a person for anything if their actions were against the law.
Research, particularly in the US, has focused on prejudice as a factor in police interactions but Dr Hendy said his study found no overt discussion of racist behaviour or other prejudices against individuals.
But he did notice stereotypes when it came to locations, particularly student and entertainment quarters on Friday and Saturday nights.
Alcohol and violence-related disorders are more common in those areas and tended to result in targeting of "young men likely to get drunk and go silly", he said.
Australian Associated Press