Over the last week, the Kahui family has come in for vicious criticism for exercising their right to silence. So what's the alternative? National's Richard Worth plagarises wikipedia to remind us of what we used to do in the past:
Peine forte et dure (Law French for "long and forceful punishment") was a method of torture formerly used in the common law legal system, where a defendant who refused to plead ("stood mute") would be subjected to having heavier and heavier stones placed upon his or her chest until a plea was entered, or as the weight of the stones on the chest became too great for the victim to breathe, suffocation would occur.
(This seems to clash with claims from the Law Lords that "the English common law has regarded torture and its fruits with abhorrence for over 500 years", and that torture had traditionally been performed under colour of the royal prerogative rather than the courts (read the full judgement) - but that seems to have been about using torture to extract evidence rather than getting people to plead)
While I'm sure that critics of the right to silence are as horrified as I am at the thought of pressing answers from people with heavy stones, it does make the problem clear. What exactly do they propose be done with people who refuse to talk to the police? Stick them in a cell until they do? Torture them? Not only would either be a gross violation of fundamental rights; it would also result in the police being told whatever they wanted to hear. That's probbaly fine if, like the police, you want to "make someone responsible" (rather than find who is responsible) - but if you are concerned about justice and finding out who is actually guilty, then it should be an anathema.