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

helpful” in assessing that person’s truthfulness. The Commission says in its
commentary:
The Commission’s desire is to propose a test of significant or
heightened relevance so as to prohibit truthfulness evidence that is of
limited value. 18 The substantial helpfulness test is aimed at admitting
only evidence that will offer real assistance to the fact-finder. …
Some commentators did not support introducing the substantial
helpfulness test, arguing that such a test would cause unnecessary
uncertainty. The Commission considered other tests (such as
“necessity” or “direct relevance”) but concluded, with the support of
other commentators, that those alternatives would not provide any
greater certainty. 19
7.14 Little guidance is available in the case law on either side of the Atlantic on the
meaning of “substantial relevance”. There is little authority in this jurisdiction on
the meaning of “substantial relevance” that is pertinent to bad character
evidence. The closest is the advice given to judges to help them guide juries in
the context of mental responsibility. 20 Juries are told to interpret the word
“substantial” in the context of mental impairment in a broad common sense way,
or to take it as meaning more than trivial but less than total. 21 In the United
States, in the civil law, “substantial evidence” has been interpreted to mean such
evidence that a reasonable mind might accept as adequate to support a
conclusion, or evidence which possesses something of substance and relevant
consequence.
7.15 The concept of “substantial effect” is utilised in the employment law area of
disability discrimination. A “substantial effect” is one that is significant or greater
than de minimis, in other words, more than minor or trivial, but it does not have
to be large or considerable. 22 Factors for assessing what is substantial are set out
in “Guidance” which is issued by the Secretary of State under section 3 of the
Disability Discrimination Act 1995. The guidance gives illustrations and
examples but is not a checklist. 23
7.16 Professor McEwan wrote,
There must be doubts as to the likely efficacy of [a provision limiting
imputations to those which substantially undermine a witness’s
credibility] in the light of the disastrous failure of section 2 of the
18 The concept of “heightened” relevance can also be found in s 13 of the Evidence Act
1908. As such it is not an unfamiliar concept (footnote in original).
19 NZLC, Evidence: Reform of the Law (1999) Report 55(1), paras 157–158.
20 Egan [1992] 4 All ER 470.
21 Lloyd [1967] 1 QB 175.
22 See A Samuels, “Disability Defined” [2000] 144 SJ 424.
23 Vicary v British Telecommunications Plc [1999] IRLR 680, EAT.
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