Clarke v Crown Prosecution Service

Factual and Procedural Background

This appeal arises from the conviction of the Appellant by lay justices at the Staines Magistrates' Court on 3 September 2012 for exceeding the 50mph speed limit on the A30 Egham by-pass on 8 March 2012. The trial centered on the accuracy of a speed-measuring device used by a police officer, CSO Bernath, who had over two years' experience and employed an Ultralyte 20/20 device to record a speed of 68mph. The officer conducted multiple checks on the device's accuracy during the day, including distance checks at the site and at the police station, with the device indicating no errors. The Appellant challenged the verification of the device's accuracy, arguing that the distance used for calibration at the police station had not been personally measured by the officer and that no direct evidence of this measurement was presented. The justices ultimately found the case proven, relying on the officer's checks and the device's readings.

Legal Issues Presented

1. Whether the court was entitled to rely on hearsay evidence regarding the measurement of the test site distance.
2. Whether the court was entitled to rely on the accuracy of the speed-detection device in the circumstances of this case.
3. Whether it was correct not to follow the Scottish case of Cox v Procurator Fiscal, which suggested direct evidence of measurement is required to vouch for the accuracy of approved devices.

Arguments of the Parties

Appellant's Arguments

• The accuracy of the speed-measuring device had not been properly verified as required, particularly as the officer had not personally measured the test site distance at the police station.
• There was no direct evidence of the measurement used to verify the device's accuracy, and hearsay evidence was not permitted.
• Reference to the Scottish authority Cox v Procurator Fiscal, which requires direct evidence of measurement to vouch for device accuracy, was urged as preferable to English law.
• The operator's manual for the device recommends a fixed distance test each time the device is used, which was not fully complied with.
• The Association of Chief Police Officers (ACPO) Guidelines suggest officers should record evidence of range measurements in statements for court use.
• There have been cases of device malfunction, which should caution against presuming accuracy without direct evidence.
• The law in England and Wales should align with recent Scottish jurisprudence concerning laser speed-measuring devices.
• The court should adopt the evidential principle from Seroka v Redhill Magistrates' Court that evidence based on unverified device measurements is inadmissible.

Respondent's Arguments

• There was no evidence raising doubts about the accuracy of the device, which was self-checking and provided secondary corroboration to the officer's opinion.
• Another officer's prior measurement of the test site distance forms part of the police business records and is potentially admissible under section 117 of the Criminal Justice Act 2003.
• Domestic jurisprudence supports reliance on such devices without strict requirements for testing each time, as established in cases such as Nicholas v Penny, Swain v Gillett, and Connell v DPP.
• The divergence between English and Scottish law is not sufficient reason to overturn established English law, which has operated effectively for decades.
• Operator's manual recommendations and ACPO Guidelines are best practice suggestions rather than mandatory legal requirements.
• There was no evidence that the distance measurement was incorrect or that false information was supplied.

Table of Precedents Cited

Court's Reasoning and Analysis

The court analyzed the appellant's challenge to the device's accuracy and the admissibility of hearsay evidence regarding the test site measurement. It acknowledged the appellant's reliance on Scottish authority and guidelines recommending best practices for device testing but emphasized that these do not impose absolute legal requirements. The court reaffirmed the longstanding English law principle that corroboration of a police officer's speed opinion by a speed-measuring device does not require proof of device testing on each occasion, unless there is reason to doubt its accuracy. The officer's multiple checks during the day, the device's self-checking features, and the absence of any error readings or contradictory evidence supported the reliability of the device readings. The court rejected the argument that hearsay evidence concerning the distance measurement was inadmissible, noting it did not need to decide this point to resolve the appeal. The court declined to overturn established English law in favour of Scottish jurisprudence, finding no evidence that the latter was preferable or that the device was malfunctioning or improperly tested. Consequently, the court held that the justices' approach was sound and the conviction was properly supported by sufficient corroborative evidence.

Holding and Implications

The appeal is dismissed.

The court upheld the conviction, confirming that in English law a speed-measuring device need not be tested for accuracy on each occasion to provide corroborative evidence, absent specific reasons to doubt its reliability. The decision reinforces the established evidential framework and does not impose new procedural or evidential burdens on the prosecution. No broader changes to precedent were made, and the ruling maintains the current divergence between English and Scottish approaches to speed-measuring device evidence. The direct effect is that convictions based on similar devices and procedures remain valid where the device is shown to be functioning correctly and no credible challenge to its accuracy is presented.