Clark, R v

A trial judge may properly control expert evidence, require a witness to answer the question asked, exclude speculation and prevent evidence outside the witness’s proper expertise. The judge may also probe the evidence for clarification, provided that the judge does not assume the role of prosecutor.

Interventions during defence evidence may render a conviction unsafe if they improperly prevent relevant admissible evidence being put before the jury, disrupt its presentation so as to impair the jury’s assessment, or display partisanship or bias. The question is one of the overall effect of the interventions in their context.

The appellant was convicted at Taunton Crown Court of two counts of rape of a child and one count of inciting a child to engage in sexual activity.

His defence was that the allegations were untrue. He called a child psychologist who criticised the manner in which the child’s ABE interview had been conducted. The appellant appealed against conviction on the sole ground that the trial judge’s interventions during the psychologist’s evidence displayed hostility amounting to bias.

The Court of Appeal heard a recording of the evidence, as well as considering the transcript. The central issue was whether the interventions had unfairly restricted the expert’s evidence or created an appearance of partisanship capable of undermining the safety of the convictions.

1. Appeal dismissed. The Court concluded that there was no reason to doubt the safety of the convictions.

2. A judge’s interventions during defence evidence may be objectionable where they prevent a witness from properly giving admissible evidence, or disrupt the evidence so as to impair the jury’s assessment of it. They may also be objectionable if their overall effect displays partisanship or bias and risks poisoning the jury’s minds. Those risks must be assessed in their full context.

3. A judge nevertheless has a responsibility to ensure that a witness answers the questions asked, does not stray into irrelevant or inadmissible matters, and does not give evidence beyond the proper scope of the witness’s expertise. The judge may seek clarification and probe evidence, although it is generally wise to reserve probing questions until the end of the witness’s evidence so as to avoid appearing to adopt the prosecutor’s role.

4. The psychologist was able to place his principal criticisms of the ABE interview fully before the jury. The judge’s occasional interventions for clarity and concision did not prevent the proper presentation of that evidence. The judge was entitled to stop speculative evidence about what unidentified persons might have said to the child between two dates. That subject was outside the expert’s report, depended on facts unknown to the expert, and concerned matters within ordinary jury experience rather than specialised knowledge.

5. The judge was also entitled to prevent the expert from answering whether the interview information was reliable, and from speculating about what prosecutors would normally do following a poor interview. Although the judge briefly raised his voice while stopping the latter evidence, this occurred after repeated attempts to keep the witness within proper bounds. It did not amount, or come close, to impropriety or bias.

• Court of Appeal (Criminal Division): dismissed the appeal against conviction.
• Taunton Crown Court: convicted the appellant on 7 January 2011 of two counts of rape of a child and one count of inciting a child to engage in sexual activity.