a bad idea and don't do it
Radio NZ has this explainer on citizen's arrests up today. The headline reads:
Explainer: What is a citizen's arrest and how do you make one?
Quite simple answers to this question:
A citizen's arrest is a bad idea.
Don't do it.
There's a reason why people with expertise in these matters, such as the Police and Retail NZ, have consistently opposed the government's expansion of citizen's arrest.
For me, the key thing lies in one of the points Radio NZ has taken from the Police website, my emphasis added:
Avoid using force. Only use force if it is necessary and proportionate and use the minimum required. What amounts to "reasonable force" will depend on the circumstances;
The article discusses the concept of reasonable force, and how the Police have training in reasonable force but still sometimes get it wrong. There is no clear definition of reasonable force on offer. Or, think about it this way: If you need the Radio NZ explainer on the the citizen's arrest rules, then you do not have the training, expertise, or experience necessary to make a citizen's arrest, and you are highly likely to run afoul of the reasonable force rule.
You are also going to put yourself in unnecessary danger. The Police are paid to put themselves in danger, and they have training and equipment for that purpose. You are not, and you do not.
Radio NZ's article gives examples of people who have died when they tried to confront a shoplifter, and of course a young man in Hamilton has now been charged with assault after an attempted citizen's arrest.
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.
"He" being Kris Gledhill, a law professor at AUT that Radio NZ consulted for their explainer.
A wee bit of a tangent: I really worry about what all these superhero comics and movies say about the USA's collective state of mind. And it's not just superheroes - the vigilante seeking justice he was denied through the system is a theme running through American media. And this justice is often sought through the medium of extreme violence - it's not justice at all, just retribution.
The real world has no clear distinction between goodies and baddies. In the real world the use of extreme violence will blow back on you, and that blowback will come either in the form of the person you are trying to arrest being a better, faster, stronger fighter than you, resulting in you being hurt or killed; or in the form of you doing serious prison time for actions that go beyond reasonable force.
If you see a crime being committed, first make sure that you are safe, then call the Police. That's what they're there for.