A police officer’s assessment of a defendant’s speed could be corroborated by evidence as to the reading of a speedometer, even if the latter device had not been checked for the accuracy of its reading, unless there were particular reasons for deciding otherwise. ‘The question in the present case is whether, if evidence is given that a mechanical device, such as a watch or speedometer, recorded a particular speed or a particular time, that recording is prima facie evidence on which the court can act. In a particular case the court might refuse to act on it, but here counsel for the respondent called our attention to the fact that the difference is very great. The offence is driving at a speed exceeding thirty miles an hour, and the evidence is that the speedometer showed that the appellant was exceeding that speed by ten miles an hour. It would be a very considerable error if the speedometer was as much out as that.’
There is a very well-established presumption in the law of evidence that a measurement made by a technical or scientific instrument is accurate, if the instrument is of a type which as a matter of common knowledge or experience may be expected to be accurate. In my opinion, a tape measure is undoubtedly such an instrument.
Lord Goddard CJ set out the doctrine of ‘per incuriam’, saying: ‘ ”Per incuriam’ are those decisions given in ignorance or forgetfulness of some inconsistent statutory provision or of some authority binding on the Court concerned, so that in such cases some part of the decision or some step in the reasoning on which it is based, is found, on that account to be demonstrably wrong.’
Lord Goddard
[1950] 2 KB 466, [1950] 2 All ER 89
England and Wales
Cited by:
Cited – Iaciofano v Director of Public Prosecutions Admn 15-Jul-2010
iacioganio_dppAdmn10
The defendant appealed against his conviction for speeding, saying that the device used to measure his speed was not approved. The only evidence relied on was that the officer said it had been installed in many police vehicles.
Held: The . .
Cited – Iaciofano v Director of Public Prosecutions Admn 15-Jul-2010
iacioganio_dppAdmn10
The defendant appealed against his conviction for speeding, saying that the device used to measure his speed was not approved. The only evidence relied on was that the officer said it had been installed in many police vehicles.
Held: The . .
Cited – Clarke v Crown Prosecution Service Admn 7-Feb-2013
The defendant appealed against his speeding conviction, seeking to challenge the accuracy of the police officer’s speed measuring device.
Held: The appeal failed. There was not the need to certify the device in the way suggested by the . .
Lists of cited by and citing cases may be incomplete.
Updated: 07 August 2021; Ref: scu.424958
