An accused person is never required to prove his innocence: his silence can never displace the onus that is on the prosecution to prove his guilt beyond reasonable doubt. A failure to offer an explanation does not of itself prove anything. Nor does it, in any strict sense, corroborate other evidence. But the failure of an accused person to contradict on oath evidence that to his knowledge must be true or untrue can logically be regarded as increasing the probability that it is true. That is to say a failure to deny or explain may make evidence more convincing, but it does not supply its deficiencies.
It is important that a trial judge should ensure, especially if any comment is made on an accused's decision not to give evidence, that juries do not use impermissibly the failure to testify. At the least, the jury must be told that the accused is not bound to give evidence and that the onus remains on the prosecution to prove guilt beyond reasonable doubt [35] . The limited use which can be made of an accused's failure to testify is of special importance when the prosecution case depends upon the drawing of an inference of guilt from the facts proved directly by evidence. In such a case, the jury must not use a failure to testify as a fact, albeit in conjunction with other facts, from which they might infer the accused's guilt [36] . If there is insufficient evidence of the facts from which an inference of guilt could be drawn, a failure to testify cannot supply the deficiency. But the jury may draw inferences adverse to the accused more readily by considering that the accused, being in a position to deny, explain or answer the evidence against him, has failed to do so. In Wilson v Buttery [37] , Napier J. said:
If the truth is not easily ascertainable by the prosecution, but is probably well known to the defendant, then the fact that no explanation or answer is forthcoming as might be expected if the truth were consistent with innocence, is a matter which the Court or jury may properly consider.
Citing this passage in Morgan v Babcock & Wilcox Ltd [38] , Isaacs J. held that, as the affirmative evidence in the case raised "a strong probability" that it was the defendant Company that had paid, or had caused to be paid, the bribe the subject of the charge in that case, "the silence of the Company, and its failure to explain, materially weakens any attempt to suggest in its favour possible hypotheses of innocence". In May v O'Sullivan this Court said [39] :
After the prosecution has adduced evidence sufficient to support proof of the issue, the defendant may or may not call evidence. Whether he does or not, the question to be decided in the end by the tribunal is whether, on the whole of the evidence before it, it is satisfied beyond reasonable doubt that the defendant is guilty. This is a question of fact. In deciding this question it may in some cases be legitimate, as is pointed out in Wilson v Buttery, for it to take into account the fact that the defendant has not given evidence as a consideration making the inference of guilt from the evidence for the prosecution less unsafe than it might otherwise possibly appear: cf. Morgan v Babcock & Wilcox, per Isaacs J. [38] . But to say this is a very different thing from saying that the onus of proof shifts.
1. (1964) 118 C.L.R. 600, at p. 613.
2. See R v Templeton , [1922] Q.S.R. 165, at p. 171; Reg v Phillips , [1967] Qd R. 237, at pp. 292-293; Reg v Fellowes , [1987] 2 Qd R. 606; Reg v Hocking , [1988] 1 Qd R. 582.
3. (1964) 118 C.L.R., at p. 614.
4. (1964) 118 C.L.R., at p. 615.
5. Waugh v The King , [1950] A.C. 203, at p. 212; Reg v Bathurst , [1968] 2 Q.B. 99, at pp. 107-108.
6. In this sense, it may be said that an accused's failure to give evidence "has no evidential value": Reg v Sparrow , [1973] 1 W.L.R. 488, at p. 495; [1973] 2 All E.R. 129, at p. 135; (1973) 57 Cr. App. R. 352, at p. 362.
7. [1926] S.A.S.R. 150, at p. 154.
8. (1929) 43 C.L.R. 163, at p. 178.
9. (1955) 92 C.L.R. 654, at pp. 658-659.
10. (1929) 43 C.L.R. 163, at p. 178.