R V. Turner (1975)
Definition
The foundational UK Court of Appeal authority on expert-witness admissibility. Expert evidence is admissible only where it deals with matters outside the ordinary knowledge and experience of the jury. Where the jury can form their own conclusion, expert assistance is not needed.
- Court
- England and Wales Court of Appeal
- Year
- 1975
- Core rule
- Expert evidence must be outside ordinary jury knowledge
Common questions
What is the practical test Turner sets for admitting expert evidence?+
If jurors can form a sound conclusion from the facts using their own common knowledge and experience, expert opinion on that point is unnecessary and may be excluded, even if the expert's evidence is otherwise reliable.
How does Turner apply to psychological or psychiatric testimony?+
The case itself concerned psychiatric evidence about a defendant's personality; the court held that ordinary jurors can assess normal human behaviour and motive without expert help, so such evidence is only admissible where it addresses conditions outside common experience.
Related terms
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- BSA 2023 § 39
- Section 39 of the Bharatiya Sakshya Adhiniyam 2023, the provision governing expert opinion evidence in Indian courts. Replaced Indian Evidence Act 1872...
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- Frye Standard
- The US legal test for admissibility of scientific evidence, originating from Frye v. United States (1923), which required that a technique be...