Mulindwa, R. v

Under section 35 of the Criminal Justice and Public Order Act 1994, whether it is undesirable for an accused person to give evidence is a broad assessment of all relevant circumstances. Mental illness and difficulty in giving evidence do not, without more, make it undesirable to do so where suitable safeguards can enable fair participation.

Expert psychiatric or psychological evidence may explain how a recognised mental disorder may affect a witness’s presentation. It must be strictly confined to assisting the jury to understand that presentation. An expert may not express an opinion on truthfulness, credibility or the reliability of particular answers, which remain matters for the jury.

The defendant was convicted in the Crown Court at Kingston-upon-Thames of conduct in preparation of terrorist acts, contrary to section 5(1) of the Terrorism Act 2006. He suffered from paranoid schizophrenia, controlled to a substantial extent by medication.

Before deciding whether to give evidence, he contended that his mental condition made it undesirable for him to do so under section 35 of the Criminal Justice and Public Order Act 1994. The trial judge rejected that contention. He considered that short periods of evidence, simple questions and limited psychological evidence explaining the defendant’s presentation could provide adequate safeguards. The defendant did not testify, an adverse-inference direction was given, and he was convicted.

On his renewed application for leave to appeal against conviction, the central issue was whether the contemplated use of the psychologist’s evidence was lawful and whether the section 35 direction rendered the conviction unsafe.

1. The court refused the renewed application for leave to appeal. There was no arguable error of law in the trial judge’s conclusion that it was not undesirable for the defendant to give evidence and that an adverse-inference direction could be given under section 35 of the Criminal Justice and Public Order Act 1994.

2. The question of undesirability is broad. The court must consider the accused’s condition and the available safeguards together. Here, the defendant could have been assisted by short phases of evidence, straightforward questions, repetition where needed, and an explanation of behavioural features caused by his illness. Those measures were capable of addressing the difficulties identified by the psychologist.

3. Medical expert evidence may be admissible where it assists the jury to understand how a recognised mental disorder may affect a witness’s presentation. Consistently with Toohey v Metropolitan Police Comr [1965] AC 595 and the later criminal authorities, the permissible evidence concerns the medical condition and observable effects relevant to the jury’s assessment. It may not invade the jury’s exclusive function by stating whether the witness is credible, truthful, or reliable, or by commenting on individual answers.

4. The trial judge’s reference to evidence from the psychologist “as necessary” was properly understood in its context. It meant a strictly limited explanation, before the defendant gave evidence, of possible features of his presentation. It did not authorise answer-by-answer expert commentary. The jury in any event received agreed evidence of the defendant’s continuing condition and could take it into account when considering his silence.

5. Under section 79 of the Police and Criminal Evidence Act 1984, the court could in its discretion permit a psychiatrist or psychologist to give that limited explanatory evidence before the accused. The conviction was not unsafe.

• Court of Appeal (Criminal Division): refused the renewed application for leave to appeal against conviction in [2017] EWCA Crim 416.
• Crown Court at Kingston-upon-Thames: on 27 November 2015, convicted the defendant of conduct in preparation of terrorist acts; on 21 December 2015, imposed six years’ imprisonment with associated orders.