Evidence of Bad Character in Criminal ... - Law Commission

extends to all bad character evidence which is outside the central set of facts, 23
not just to evidence going to credibility.
THE DANGERS OF BAD CHARACTER EVIDENCE
Its irrelevance
9.14 We have considered in Part VI above what evidence there is to show how and to
what extent past conduct might be relevant at trial (to propensity and to
credibility) in relation to defendants. The conclusions we draw have the same
force in relation to non-defendants. We concluded that in relation to propensity,
past behaviour can be probative on the question whether the defendant is likely to
have acted in the way alleged, but the probative value of a single previous
instance can be easily over-estimated, and this would seem to be as true for nondefendants
as for defendants. In relation to credibility, we concluded that
previous misconduct may be relevant to a witness’s general credibility; but, since
little significance can in any event be attached to that credibility or the lack of it,
the witness’s previous misconduct is generally of little value in determining the
issues in the case. A person’s specific credibility – that is, the extent to which, in
the circumstances of the individual case, the witness appears to have a reason to
lie – is of far more importance in a case, as Professor Eggleston, an Australian
judge, wrote:
For my own part, I would … limit severely the scope of crossexamination
as to credit. As most witnesses will lie if the motive is
strong enough, and many will lie merely to save lengthy explanations
about matters that they think have nothing to do with the case, I do
not regard the demonstration that a witness has lied about some
irrelevant matter as affording much help in deciding whether he is
telling the truth about the facts in issue. 24
9.15 The New Zealand Law Commission took the view that bad character evidence is
generally unhelpful on matters of truthfulness, and that restrictions are needed
in respect of truthfulness, evidence showing a propensity in the defendant, and
evidence about the sexual experience of a complainant. The restriction on
evidence going to a person’s truthfulness reads:
A party may offer evidence in a civil or criminal proceedings about a
person’s truthfulness only if the evidence is substantially helpful in
assessing that person’s truthfulness. 25
The Commission has also recommended special rules for propensity evidence
about defendants and about sexual experience of complainants. 26
23 The concept of the “central set of facts” is explained at paras 8.26 – 8.28 and 8.31 above.
24 R Eggleston, Evidence, Proof and Probability (2nd ed 1983) p 77.
25 Clause 39(1). Additional rules apply if the person whose truthfulness is in issue is a
defendant in criminal proceedings.
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