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

(2) C, having become aware that E has made allegations against D, goes to the
police (or responds to a trawl by investigators) to make false allegations on her
own initiative.
(3) F and G make an agreement both to say that D was wearing a dark blue top.
They may be pooling their recollection and honestly agreeing what their
recollection must have been. Neither of them may be sure what colour he was
wearing but they agree to say the same thing so as to give the impression that they
are sure. The agreement may be the result of negotiation in which F is persuaded
by G, or agrees without really being persuaded, to adopt G’s recollection.
(4) H learns that J has said D’s top was blue, and decides to change or add to her
evidence to the same effect, without colluding with J at all. She may be telling a
deliberate lie, or have been unconfident about what colour D’s top was and so, on
hearing that J thinks it was dark blue, resolves that she will also say it was dark
blue, and believes she was mistaken in thinking it might have been green. In this
scenario, the alteration is conscious, but there is no collusion in the sense of
conspiracy.
(5) K is unconsciously influenced by L and changes her recollection and account
so that she too says D was wearing a dark blue top, without being aware that she
has changed it. That is Lord Mustill’s “innocent infection”.
15.5 Situations (1) and (3) involve collusion (in the first, complete concoction, and in
the third, collusion as to an element of the evidence) and (1) and (2) involve
concoction. Situations (2), (4) and (5) may all be described as “contamination”,
but only (5) is “innocent infection”.
15.6 It is mistaken to correlate collusion as in (3) with false allegations, and
contamination (as in (4) or (5)) with an essentially truthful story. F and G may
be essentially right that D did what they allege, even though they have agreed to
gild the lily to make it sound better. Conversely, K’s central allegation, which
chimes with L’s through innocent infection, may be a complete (though
unwitting) fabrication.
15.7 A jury or bench of magistrates could allow that there had been collusion (in the
sense of (3) or contamination (as in (4) or (5)) and yet properly convict. They
could not, though, accept the falsity of concoction (1) and properly convict. In
(2) they could only properly convict of E’s allegations, not C’s.
THE QUALITY OF EVIDENCE AND ADMISSIBILITY
15.8 Contamination and collusion have the potential to affect decisions at two stages
in the trial: at the time the evidence is ruled admissible or inadmissible, and after
the evidence has been given. We now consider what view the court should take of
the quality of bad character evidence at the time of ruling on admissibility.
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