Leo Sawrij Ltd v North Cumbria Magistrates' Court

In criminal proceedings, an expert’s connection with the party calling him does not, by itself, make his opinion evidence inadmissible. The connection may affect the weight of the evidence. Admissibility depends on whether the subject falls within a class suitable for expert evidence and whether the witness has sufficient knowledge through study or experience. An expert may also assist before trial by informing cross-examination of opposing witnesses. Costs incurred for that purpose may therefore fall within a defence costs order, subject to the ordinary rules on disclosure and the control of excessive expert evidence.

The claimant appealed by way of case stated from the decision of District Judge Chalk in the North Cumbria Magistrates’ Court. The prosecution case under the Environmental Protection Act 1990 and the Water Resources Act 1991 was dismissed at the close of the prosecution evidence. The district judge granted a defence costs order under section 16 of the Prosecution of Offences Act 1985, but excluded the pre-trial costs of David Green, whom the claimant intended to call as an expert witness.

The district judge considered that Mr Green’s commercial connection with the claimant affected his status and also concluded, without argument, that the issue was one of legal rather than scientific interpretation. The questions were whether Mr Green was correctly excluded as an expert and whether his pre-trial costs were recoverable.

1. The appeal was allowed. The answer to both questions stated by the district judge was negative.
2. Expert evidence in criminal proceedings is admissible where the subject matter falls within a class on which expert testimony is admissible and the witness has acquired sufficient knowledge through study or experience to make his opinion valuable in resolving the issues. The court accepted that this was the correct position, reflected in Bonython and relevant authority including R v Stubbs.
3. A commercial or other connection between an expert and the party calling him does not automatically render the evidence inadmissible. Such a connection may affect the weight to be given to the evidence. The district judge had therefore taken the wrong approach in treating Mr Green’s connection with the claimant as determinative of admissibility.
4. The district judge had also erred in deciding, without inviting submissions, that the issue was purely one of legal interpretation and did not require expert evidence. The parties should have been given an opportunity to address that issue.
5. The purpose of an expert is not confined to giving evidence at trial. Expert assistance may be used in cross-examining opposing witnesses. The associated pre-trial costs were consequently capable of being recovered under the defence costs order.
6. The appropriate course was to make a full defence costs order, including Mr Green’s costs as an expert, for assessment by the appropriate court officer. The decision was narrow and did not authorise the indiscriminate instruction of experts. The ordinary rules concerning prior disclosure and excessive expert evidence remained applicable.

• High Court (Administrative Court): appeal by way of case stated allowed; the questions were answered in the negative and a full defence costs order including the expert’s costs was directed.
• North Cumbria Magistrates’ Court: District Judge Chalk dismissed the prosecution at the close of the prosecution case, granted a defence costs order under section 16 of the Prosecution of Offences Act 1985, but excluded the expert’s pre-trial costs.