Explainer - Do you plan on making a citizen's arrest any time soon? There are some things you might want to know first.
Last month, Parliament passed an amendment bill updating the Crimes Act to include an expansion of citizens' arrest powers.
Members of the public can now detain others for Crimes Act offences including theft, assault or burglary.
The changes drew strong criticism from the police association, retailers and others, while Justice Minister Paul Goldsmith said it would help crack down on retail crime and allow security guards and others to legally detain thieves.
"Our government is committed to fixing the basics in law and order, and that means ensuring retailers are being effectively protected, are empowered to stop offending, and that offenders are caught and deterred from doing it again," Goldsmith said.
The changes took effect in early August, but last week saw a 19-year-old become the first person who was arrested over trying to do a citizen's arrest himself.
Police said the man detained an alleged shoplifter, but then assaulted them during the incident.
The Hamilton incident has fired up critics of the citizen's arrest laws.
So what exactly is a citizen's arrest, what are the rules and how can it go too far?
The idea of a citizen's arrest dates all the way back to English common law. It basically means anyone who's not a police officer making the claim to arrest someone for committing a crime, and then holding them for the authorities.
First off, you don't actually need to be a citizen, despite the name.
"Any person in New Zealand is able to make a citizen's arrest as per the provisions detailed under the relevant sections of the Crimes Act," a New Zealand Police spokesperson said.
There's also no requirement to be over 18 to make a citizen's arrest, police said.
Police do say would-be arresters should know "your safety comes first" and an arrest could "carry legal and personal risk".
"The risk of serious harm to yourself and others can be heightened if a situation escalates," their website states.
"In most situations, the safest action is to keep yourself and others safe, observe the crime, and call 111 and ask for police."
Auckland University of Technology law professor Kris Gledhill recently wrote about the new powers for RNZ.
"The amendments to the law relating to citizen's arrests have not reduced the complexity of the law to any significant extent; and there are no doubt false summaries circulating about what people can do, both about when you can arrest and what you can do on arrest," he said.
Changes to the Crimes Act have expanded powers to make a citizen's arrest - but there are many rules to follow. 123rf
On their website, police say to make a citizen's arrest you must:
You also must keep the person detained safe, and are responsible for determining whether the person needs medical assistance and if they are vulnerable physically or mentally.
"Do not kneel or sit on the person, or apply pressure to the neck or head," police warn, and be aware of the risk of suffocation.
"Remember if you are found to have used excessive force, unlawfully arrested someone or failed to follow police directions without reasonable excuse, you may face criminal or civil legal action," the website warns.
Adults can also arrest youths and even children, the police spokesman confirmed - but there are rules in place about doing such things.
"There is no age-based restriction on arresting a child or young person," they said.
"While a member of the public may lawfully carry out a citizen's arrest where the criteria are met, the subsequent police response remains subject to the legislative framework that applies to children and young people in the Oranga Tamariki Act."
Gledhill said that the law remains complex and easily misunderstood, and even the police information on it may cause confusion in the courts.
He said, as an example, that while the police information says people should believe an offence against the Crimes Act "has been committed" by the person, Section 35 in the Crimes Act says the person should be found "committing any offence against this Act." (Italics added for emphasis.)
There is "a general principle that if you think you are acting within the law but you are not, you cannot rely on your mistaken belief about your powers - that is, if you have got the law wrong, you might end up committing a criminal offence," he said.
Retail crime was given as one reason for citizen's arrest changes. RNZ / YouTube
Well, that's where it gets tricky. One person's reasonable force may be another person's excessive force.
"It's important to always think what is 'reasonable and proportionate' in the circumstances," the police spokesperson said.
Section 39 of the Crimes Act allows "such force as may be necessary to overcome any" resistance when making arrests.
To get specific, it reads: "Justification or protection shall extend and apply to the use by him or her of such force (for example, the use of physical or mechanical restraints) as may be necessary to overcome any force used in resisting such execution or arrest, unless the sentence, warrant, or process can be executed or the arrest made by reasonable means in a less violent manner."
That could, in theory, include the use of cable ties to restrain someone, but that could also be done in a way that could be considered excessive force.
"If people exercise the citizen's arrest powers, the starting point is that an arrest can be made by words alone," Gledhill said. "Force can only be used if that is 'necessary' to overcome resistance or to prevent escape."
The New Zealand Police Association has been critical of the citizen's arrest changes, and its president Steve Watt said one of the concerns is around what reasonable force might be.
"Reasonable force is a widely misunderstood concept that can have serious consequences if applied incorrectly," Watt said.
"In its simplest form, it means you may use only the amount of force necessary to overcome the force being used against you. Permitting untrained members of the public to apply such a concept is an unjustifiable gamble."
It's too easy for people to assume they know how to make a citizen's arrest from what they see on TV, Gledhill said.
"This is language that risks being inflammatory because people watch too many TV programmes, particularly based in the US, where force is more or less always used on arrest and people are by default placed into handcuffs. That is simply not the law in New Zealand: restraints can still only be used if that is 'necessary'."
"Even police officers, despite their extensive training and experience, can sometimes face challenges when assessing and applying the concept of reasonable force," Watt said.
"This is where people can find themselves in trouble. What may seem reasonable to someone involved in a confrontation may not appear reasonable to an observer (the courts) taking a step back and reviewing the situation afterward."
The Crimes Act Amendment Bill changed the rules so that people could intervene to stop any Crimes Act offence at any time of day.
Before that, people could make a citizen's arrest at night between 9pm and 6am where there were reasonable grounds for believing a person was committing a crime.
A citizen's arrest could also be carried out during daytime for an adult suspected of committing a crime punishable by more than three years' imprisonment.
There were also changes to certain sections of the Crimes Act to the protections an individual has when making a citizen's arrest, including being able to arrest a person without a warrant if they're committing a covered offence.
Paul Goldsmith. RNZ / Samuel Rillstone
The justice minister has stood by the policy. After the Hamilton arrest, Goldsmith told RNZ there were "clear directions" over what people should do.
"We passed a law and we expect people to follow that law. The clear directions in that is if the situation is appropriate, people can hang on to somebody and then call the police and follow the instructions of the police."
However, before its passage, groups including the New Zealand Police Association and Retail NZ opposed the changes.
Before they were finalised, Watt called the recommendations a "train wreck waiting to happen".
"In the association's submission on the legislation we noted 'A civilian attempting a citizen's arrest is at high risk of either using too much force and exposing themselves to an assault charge, or, using too little force and being injured themselves, and unable to safely detain the suspect'."
There are also many possible dangers for retail workers in confronting suspected shoplifters.
Auckland dairy worker Janak Patel was stabbed to death in 2022 when he chased after a shoplifter, while a teenager was jailed after killing a security guard who tried to stop him at a Papakura Countdown in 2019.
Gledhill described the changes as one that "could open a legal can of worms".
"The minister of justice is unhelpful in saying that there is a new law and people are expected to abide by it: the message should be this remains a quagmire that will trap some people."
Goldsmith has said the legislation will be tested over time.
"Whenever there's changes to legislation there will be instances that require the judgment of the court. There'll be a period of working our way through how that works in practice."
Goldsmith said he could not comment on the specifics of the Hamilton arrest, which is before the courts.
"We're trying to send a clear message that society doesn't tolerate shoplifting; it doesn't tolerate retail crime, so we're about giving the extra tools to retailers where appropriate. But of course, they've got to follow the law."
Gledhill said there still remains a risk of people getting the law wrong.
"Parliament regularly uses phrases like what is 'reasonable' or 'necessary' and then leaves it to the courts to work out how that applies on a case-by-case basis," he said.
"Some people will end up before the courts for a decision to be made about whether something was in fact 'reasonable' or 'necessary.'"
-RNZ