Expert Witness Journal Issue 65 February 2026 - Flipbook - Page 90
statements in the prison calls which di昀昀ered
from that relied upon by the prosecution expert.
Arguably a decision signi昀椀cantly tipped against the
defence. This may be of particular relevance at a
time when drill music features prominently in many
murder cases or where defendants are said to be part
of Organised Crime Groups (‘OCGs’).
to accept it. The determination however must
be balanced and made within the context of the
evidence and the issues that are likely to arise at
trial.
Clari昀椀cation on the Mountford problem
This issue is discussed in Chapter 17 of the
Compendium, and it deals with the di昀케culties that
may arise when it is argued on behalf of a defendant
that the jury cannot determine the reason for
their failure to mention their defence without 昀椀rst
deciding whether the defence is true. In R v Mountford
[1999] Crim LR 575 the defendant was charged
with drug dealing o昀昀ences and his defence at trial
was that it was in fact ‘W’ – the main prosecution
witness – who dealt drugs. The defendant asserted
that he did not raise this defence in interview out
of fear of exposing W to prosecution. The judge
directed the jury that they could make an inference
in accordance with section 34.
Guidance on cases where the defendant’s
昀椀tness 昀氀uctuates during the proceedings
When the question of 昀椀tness to participate arises
during a trial, the decision as to the defendant’s
昀椀tness remains with the judge alone in accordance
with s.4(5) Criminal Procedure (Insanity) Act 1964.
R v Vinnell [2024] EWCA Crim 1294 provides further
guidance as to the factors a judge should consider
in determining 昀椀tness. In Vinnell, it was found that
the judge had erred in 昀椀nding that the 86-year-old
defendant in question was 昀椀t to plead and stand trial
for historical indecent assault o昀昀ences in the face of
expert evidence suggesting vascular dementia and
associated Alzheimer’s disease.
On appeal, Mountford’s conviction was quashed and
it was found that in these circumstances the jury
should have considered 昀椀rst whether the defence
advanced at trial was untrue and only then if they
found so, reject the defendant’s reason for not
mentioning this fact in interview.
The o昀昀ences alleged in Vinnell dated back to the
1970s. Two defence reports from a consultant
psychiatrist and a consultant psychologist opined
that the defendant was not 昀椀t to plead. The
Prosecution’s expert initially found the defendant 昀椀t
but having assessed the defendant a second time, the
addendum report described a signi昀椀cant cognitive
decline following which their opinion changed,
concluding the defendant was un昀椀t because
although he could still understand the charges
against him, he was no longer able to give evidence
in his own trial. The judge found that arrangements
could be put in place for those aspects of the case to
be tailored to accommodate the defendant’s needs
such as shortened court days and frequent breaks in
the proceedings.
The compendium goes on to suggest that if faced
with the Mountford dilemma, the judge should leave
the s.34 decision to the jury.
The judge’s responsibility is to ensure the jury is
properly guided through these issues and in order
to do so the juries must:
(i) First decide whether the defendant could
reasonably have been expected to mention the fact
on which they rely at trial;
(ii) If satis昀椀ed that the defendant could have
reasonably mentioned the fact in interview, then
consider what -if any- inferences are available from
defendant’s failure to do so.
The defendant’s conviction was quashed, the Court
of Appeal making clear that in order for a 昀椀nding of
昀椀tness to be made by the judge, all of the constituent
parts of the test for 昀椀tness to plead had to be met,
namely:
(iii) The jury might be sure of the 昀椀rst but not the
second.
(i) understanding the charges;
Etiquette on e-mail exchanges
(ii) deciding whether to plead guilty or not;
Although e-mail exchanges between advocates and
judges are acceptable within the course of a busy
criminal trial, in R v Peppiat [2025] EWCA Crim
110 the Court commented that the e-mails ought
to be uploaded onto the Digital Case System and
the content of such correspondence – whether
pertaining to legal directions or any other matter
– ought to be at least summarised in open Court
so that the discussions are on the record should
the Court of Appeal become involved as well as for
reasons of transparency.
(iii) exercising the right to challenge jurors;
(iv) instructing solicitors and counsel;
(v) following the course of proceedings; and
(vi) giving evidence in their own defence.
Plainly, the judge’s role in determining a defendant’s
昀椀tness is a crucial one and requires careful
consideration of the expert evidence presented
by both sides even though the judge is not bound
EXPERT WITNESS JOURNAL
88
FEBRUARY 2026
