I don't for a moment think the majority of comments here are under any confusion as to the powers, guidelines and laws the police are operating under. It's almost as if it's entirely possible to have an opinion that powers, guidelines and laws are overreaching or something, like you can still fully understand the law and still think it bullshit in its specific situational application.

Almost as if being annoyed by standard practice is entirely reasonable... But hey ho that's another debate isn't it.

Essentially your message here is, as been has been pointed out many times in this thread, that the words "voluntary interview" does not mean an interview which is a voluntary option for the person being interviewee.

it wouldn't really be necessary for me to come to your house, handcuff you, and put you in a cell before interviewing you.

So... The actual interview bit is involuntary?

an interview still needs to take place legally though

Nothing says voluntary like only one possible outcome in a situation!

chances are you won't come in for the interview

Which would be a perfectly acceptable everyday understanding of the word "voluntary" in every other context.

Fact is, the ultimate endgame always ends in interview. I accept and fully understand that, why that is the case, and the procedures the police need to work through. But there is no voluntary option to not be interviewed.

You can volunteer to avoid arrest, you can volunteer to find a mutually beneficial time to conduct an interview, but the act of being interviewed ultimately is not an option available to an individual.