Silence as evidence

When, if ever, is the accused’s silence at trial evidence of his guilt? The conventional view is that silence itself is not evidence of anything; it is just an absence of evidence. The significance of this absence of evidence is, conventionally, that it may strengthen the weight to be given to prosecution evidence. Adams on Criminal Law puts it this way, at CA366.02:

"Silence cannot be used to fill a gap in the evidence presented by the prosecution, or relied on to establish guilt so as to warrant the jury omitting to scrutinise all the evidence before it. However, the Judge may direct the jury that in determining the weight to be given to evidence tending to prove guilt it may accord greater weight to such evidence by an inference drawn from the absence of explanation or answer from the accused: R v Hines (No 3) (1998) 16 CRNZ 236 (CA)."

On the other hand, in R v Becouarn [2005] UKHL 55 (28 July 2005) the House of Lords approved a direction to the jury that included the following:

" … if, and I stress the word, if, if you think in all the circumstances it is right and fair to do so you are entitled, when deciding whether the defendant is guilty of the offences with which he is charged, to draw such inferences from his failure to give evidence as you think proper. In simple terms that means that you may hold his failure to give evidence against him."

Permitting "such inferences as you think proper" potentially allows the jury to use silence as if it were positive evidence of guilt. This potential was recognised by Lord Carswell (with whom the others agreed) at para 21, where reference was made to a study showing that people tend to treat credibility evidence (in the example the Court was considering, this was evidence of the accused’s convictions) as if it were propensity evidence:

" … It is, however, a matter of notoriety that juries in practice are likely to regard them as indicators of propensity and so supportive of guilt. That piece of folk knowledge received some verification from a study commissioned by the Home Office and based on research carried out on the effect of bad character evidence on mock jurors (Sally Lloyd-Bostock, The Effects on Juries of Hearing about the Defendant's Previous Criminal Record: a Simulation Study [2000] Crim LR 734)."

In Becouarn the accused at trial had attacked the character of prosecution witnesses in a way that, inevitably, would have caused the judge to permit the prosecution to cross-examine him on his own previous convictions, if he gave evidence. By not giving evidence an accused can, in these circumstances, prevent the jury learning of his record. The accused did not give evidence, and the judge directed the jury on the significance of his silence at trial, and included the comment quoted above.

Jurisdictions differ in what is regarded as appropriate judicial comment on the accused’s silence at trial. As Adams observes, CA366.02:

"It would appear that the New Zealand position to some extent represents a mid-point between English practice where stronger comment may be considered appropriate (see R v Martinez-Tobon [1994] 2 All ER 90 (CA)) and the more restrictive Australian rule, as to which see Azzopardi v R (2001) 179 ALR 349; (2001) 119 A Crim R 8 (HCA)."

The Evidence Bill does not address the contents of judicial comment, merely providing (clause 29) that "In a criminal proceeding, no person other than the defendant or the defendant’s counsel or the Judge may comment on the fact that the defendant did not give evidence at his or her trial."