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

(1) because the evidence shows that the defendant has a
propensity to commit offences of the kind with which he or
she is charged, or
(2) because the evidence reveals a combination of circumstances
that is highly unlikely to be attributable to coincidence alone.
The exclusionary rule might be formulated so as to extend to any
evidence which is adduced as the basis for an inference of either of
these kinds. 5
8.7 Our principal criticism of option B was that, while it was capable of including the
kinds of cases where a conviction is wrongly reached by a logical inference from
bad character evidence (reasoning prejudice), it inevitably omitted the kinds of
cases where a conviction was reached irrationally on the basis of such evidence
(moral prejudice). Our view is that both kinds of prejudice need to be guarded
against.
8.8 We therefore provisionally proposed option C, namely:
(1) that [subject to the exceptions proposed] evidence should be
inadmissible if, in the opinion of the court, its admission
would be prejudicial; and
(2) that, for the purpose of this rule, the admission of evidence
should be regarded as prejudicial if there is a risk that
(a) the fact-finders might treat the evidence as being
more probative of guilt than it really is, or
(b) it might lead them to convict the defendant without
being satisfied that he or she is guilty as charged. 6
This option focused on the actual risk of prejudice to the defendant – in other
words, the prejudicial qualities of the evidence, irrespective of the use to which it
might rationally be put. It had the advantages, in our view, first that no evidence
which bore a risk of prejudice would be outside the rule, because the rule itself
required the court to consider that risk, and secondly that it avoided the problem
identified with option A.
Objections to our provisional proposal
8.9 Various respondents raised the issues of the impossibility of second-guessing the
jury and the danger of usurping the role of the jury which seemed to be thrown
up by option C. The underlying concern is the difficulty of assessing exactly how
fact-finders will use a particular piece of evidence. Some respondents were
concerned that an exclusionary rule drawn in this way, although purporting to
cover all prejudicial evidence, would in fact become impotent as regards certain
pieces of evidence.
5 Para 9.77.
6 Para 9.92.
109