Carter v Director of Public Prosecutions

Where established procedures are designed to secure the accuracy of a forensic sample or analysis, the court may presume that those procedures were properly followed unless material evidence raises a real contrary issue. The prosecution must then satisfy the court that any resulting doubt is resolved.

Under section 8(2) of the Road Traffic Act 1988, a replaced breath specimen must not be used to prove the reliability of the replacement blood or urine specimen. It remains admissible as part of the circumstances and may be used, with other evidence, in assessing the defendant’s credibility.

The claimant appealed by way of case stated against his conviction at Staines Magistrates’ Court for driving with excess alcohol. He had exercised the statutory option under section 8(2) of the Road Traffic Act 1988 to replace breath specimens with a blood specimen.

The blood analysis showed not less than 93 milligrams of alcohol per 100 millilitres. The claimant argued that the prosecution had not proved that preservative was present in the blood vial and that the district judge had unlawfully used the evidential breath reading after the blood option had been exercised. The central issues were whether the analysis could be relied upon and what use could be made of the breath evidence.

1. The appeal was dismissed. The district judge had not misdirected herself and her conviction was not Wednesbury unreasonable.
2. The prosecution was not required positively to prove the presence of preservative in the vial where there was no evidential challenge suggesting that the sample had been contaminated or was otherwise incapable of reliable analysis. The evidence of the established procedures, quality assurance controls and analysis entitled the court to presume that the kit had been properly prepared and used.
3. That presumption was rebuttable. If material evidence suggested that the prescribed procedures had not been followed, or that the sample might have been affected, the prosecution would have to satisfy the court that the resulting doubts had been resolved. The opportunity for the defendant to arrange independent analysis was relevant to the proportionality of the approach under Article 6.
4. Section 8(1) and (2) of the Road Traffic Act 1988 had to be read together. The prohibition on using the replaced breath specimen was directed to proof of the reliability of the blood sample and did not make the breath evidence inadmissible for every purpose.
5. The district judge had used the evidential breath reading only as part of the material bearing on whether the claimant’s account of his alcohol consumption was credible. She had not used it to corroborate or establish the reliability of the blood analysis. That was a permissible use. The broad dictum in Smith v Geraghty was not a complete statement of the statutory effect, as explained in Yhnell v Director for Public Prosecutions.

• High Court (Administrative Court): the appeal by way of case stated against the conviction at Staines Magistrates’ Court was dismissed.