"I'll take the fifth on that": the right to silence and the presumption of innocence.

It is not a private citizen 'S duty to prove his innocence, it is the government's to prove his guilt.

--Ian Welsh

I'VE SELECTED the above quotation because it illustrates in stark form the power differential between the typical accused and the typical prosecuting authority. The alleged criminal has arrayed against him the full coercive powers of the state. For all the common gripes about an under-funded DPP/CPS or overstretched police force, taken together--along with the institutional state apparat of the courts--the power inequality is almost Kafkaesque.

While not all people are alert to the notion that a jury never finds anyone "innocent", most people--even non-lawyers--can recite the tried and true common law principle that the accused is presumed innocent. While media bodies periodically need to be reminded that incautious reporting of allegations (mainly by forgetting the word alleged or by "helpfully" photographing crime scenes) can have deeply prejudicial effects on the accused's prospects at trial, a lawyer or law student is often needed to remind ordinary folk of what the presumption means at law.

In its simplest form, the "presumption of innocence" means that the Crown, state, prosecution or what-have-you bears the persuasive burden of proof to a high standard-beyond reasonable doubt. Judges are enjoined against explaining to juries what this means during summing up, and attempts to do so have more often than not resulted in complex and costly appeals. The current Queensland Supreme Court Benchbook advises its justices to instruct juries only that the standard is high, but is to be interpreted using the words' ordinary and natural meaning.

In practice, the "presumption of innocence" is a series of interlocked sub-rules, and in some ways it's better to consider it a surrogate for the allocation of the persuasive burden of proof. The right to silence--both before and during trial, is included in this "box of rules". As I discuss later, recent changes mean considerably more "burdens" for the accused under British legislation.

What many people don't realise is that exceptions to this presumptive rule have been enshrined at common law from the start. Even Woolmington, the 1935 case that gave English law one of its most memorable expressions--"throughout the web of the English criminal law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner's guilt"--provided for exceptions based on insanity and statute. The latter have proliferated in recent times, and are central to my discussion here.