R. v. Crosthwait

52 C.C.C. (2d) 129



The breathalyser technician performed a test with a standard alcohol solution to determine weather the breathalyser was operating correctly. However, he failed to take the temperature of the room as required by the breathalyser manual. A chemist testified that even though the testing solution was stored in the same room, there would be a difference in temperature throughout the room. He could not testify as to the effect that this difference in temperature would have on the test results. He was not an expert on the breathalyser machine per se. At trial, the accused was acquitted on the grounds that this evidence would raise a reasonable doubt as to the accuracy of the readings obtained. The Crown�s appeals to the Newfoundland District Court and Court of Appeal were dismissed.

Another Issue


Functioning of approved instrument



The expert evidence illustrated no more then a possibility of inaccuracy and there was no evidence as to the extent of the inaccuracy. As the results of the breathalyser showed results 70 mg over the legal limit, it is unreasonable to assume that the effect of the testing solution being off a few degrees could have the effect of disturbing the breathalyser results by such a large margin. Therefore, the certificate of approval for the breathalyser remains uncontradicted.