You don't need to be a legal expert to answer basic questions from a Police officer about did you do something or were you in a location at a time. They aren't lawyers either! And I didn't say you couldn't ask for a lawyer and wait for one to turn up before answering...
But if they charge you for speeding, and then you wait six months until the trial, and claim only at that point that you weren't the one driving. Come on... that's a waste of society's time.
Their job is to collect evidence and send it to the prosecutor. They're given wide latitude to collect it as quickly as possible, and while law enforcement and the public attorney's offices are by and large just trying to see justice done fairly, they're almost always understaffed and over-pressured.
People act weird in pressure situations. Law enforcement personnel deal with law breaking every day, but the rest of us don't. If you're innocent and confronted with an accusation of a crime, in your resulting heightened emotional state, you don't want to say something stupid or in a way that makes you look unnecessarily suspicious.
In this situation it should be ok for you to not answer questions, wait until your involuntary adrenaline reaction wears off, and then have a conversation about it.
I don't think it is if you know someone else committed the offence and they are still out there, potentially still offending.
If you know the identity of a rapist, saying 'I'm not going to talk to the Police until convenient for me' is a rotten attitude.
Wrong. In interviews, the police can (and do) lie, lead, present circumstantial evidence as smoking guns, etc. They are not lawyers, but they are well versed in the law. They are also in all probability more experienced in asking questions and interviewing than you are, even if you're smarter than them.
Everything you say to the police can and will literally be used against you. When you speak, even if you're innocent, you give up the biggest advantage you have. ANY inconsistencies will be used against you. Words can be given uncharitably during trial. They police WILL ASK YOU QUESTIONS that a prosecutor WILL NOT BE ALLOWED to ask in a trial (speculation, leading, etc), but if you answer the police it can be used in a trial and will in all likelihood be recorded. Ever listen to yourself later and cringe? Yeah.
Even if you present a consistent story from police interview to trial, you can't even use that consistency to your benefit, but the prosecutor can use the inconsistencies against you. Your silence can't be mentioned during a trial. It cannot be used against you.
Look, if it's a speeding ticket by all means talk to the police. If saw a criminal running away, tell the police what direction they headed.
If you've been detained or are in any way at risk of it, call a laywer.
I didn't say don't.
And in the UK, what you don't say can be used against you.
> it may harm your defence if you do not mention when questioned something which you later rely on in court
Is it accurate to say that it actually can't be used in your favor, or that it simply won't be?
It is unreasonable to expect a person to know the detailed workings of the legal system. It is therefore unreasonable for there to be any negative consequences whatsoever for waiting until there is a legal expert present.