Breathalyzer readings are key evidence in drunk driving prosecutions. For that reason, attacking the accuracy of the machines is a time-honored method of evading a DUI conviction. But the Court of Appeal for Ontario thought a defendant went too far by bogging down the court in paperwork and research.
David Jackson, on trial for drunk driving, asked the judge to hand over all the records pertaining to the history and performance of the breathalyzer that delivered the bad news when he was pulled over by the police one night in Ottawa. The prosecution appealed, but the request was upheld. There was another appeal. Finally the ruling went against Jackson.
The court ruled that nothing in the records suggested that the device was unreliable, and requesting more data would just be a lot of unnecessary trouble – a fishing expedition, in the words of the Appeal Court justice.
The court also stated that just because a device had malfunctioned on a previous occasion, that device is not necessarily to be considered unreliable.
In Canada and the US too there are efforts to challenge the accuracy of the breathalyzer. Sometimes the issue is calibration – the devices must be carefully maintained and regularly calibrated in order to stay accurate – and sometimes attorneys attack the very premise of a breathalyzer. While not as accurate as a blood test, breath alcohol tests are accepted in courts around the world, at least as a preliminary method of determining intoxication.
Breathalyzer technology is also used in ignition interlocks which, in addition to recording the alcohol level in the breath, prevent a vehicle from starting if the driver has been drinking. All DUI offenders in Ontario with a blood alcohol concentration (BAC) of at least .08 must use an ignition interlock when their licence is reinstated after a suspension.
It looks as if, in Ontario at least, those arrested for impaired driving will have to accept the results of breathalyzers unless they have good reason not to.