Cracknell v Willis: HL 1988

The evidence which is admissible on a challenge to the reliability of an intoximeter device is not limited to direct evidence of the unreliability of the breath testing device, but can be based on evidence such as the level of consumption, and the activities of the defendant before arrest and on his or her condition on arrest. Lord Griffiths said: ‘In the case of a breath specimen, there is of course a presumption that the machine is reliable. But if that presumption is challenged by relevant evidence, the magistrates will have to be satisfied that the machine has provided a reading upon which they can rely before making the assumption.’ However: ‘The magistrates will remember that the presumption of law is that the machine is reliable, and they will no doubt look with a critical eye on evidence such as was produced by Hughes and MacDonald [1985] Road Traffic Act 244, before being persuaded that it is not safe to rely on the reading that it produces.’


Lord Griffiths


[1988] RTR 1, [1988] AC 450


England and Wales

Cited by:

CitedScheiner v Director of Public Prosecutions Admn 13-Jun-2006
Appeal against conviction for driving with excess alcohol – officer having mobile phone with him and turned on contrary to manufacturer’s instructions.
Held: The appeal failed. ‘This appeal should, in my view, mark the end of arguments before . .
CitedDirector of Public Prosecutions v Spurrier QBD 21-Jul-1999
It was not absolutely necessary for a defendant who asserted that a Lion Intoximeter was faulty because of a disparity between the reading and what had been drunk, to bring expert evidence to rebut the statutory presumption that the Intoximeter was . .
Lists of cited by and citing cases may be incomplete.

Road Traffic

Updated: 04 May 2022; Ref: scu.242962