Modernizing the Transportation Provisions of the Criminal Code - Discussion Paper

Proof of Alcohol Concentration

As noted earlier, many transportation offence cases are relatively simple to investigate and prove in court. However, over 80 trials have become extremely complex. In 2008, Parliament addressed the most urgent problem in The Tackling Violent Crime Act when it restricted the defences to the over 80 charge by eliminating the so-called Carter or "two beer" defence.

Proof of BAC:

The Minister of Justice has always been guided in determining which instruments and screening devices should be approved for use in Canada by the Alcohol Test Committee of the Canadian Society of Forensic Science which applies rigorous standards that are published in the Journal of the Canadian Society of Forensic Science, to determine the accuracy and reliability of equipment. Modern AIs have sophisticated electronic self-tests built in so that they will not do the analysis if the instrument is not functioning properly.

Parliament recognized in The Tackling Violent Crime Act the reliability and accuracy of modern AIs. Quite simply, if the AI properly analyzes blank air and the standard alcohol solution before each sample is taken, it is not scientifically possible for the AI to produce inaccurate readings in the analysis of the accused's breath. There are no gremlins that mysteriously falsify the breath test results of the accused but get the blank air and standard alcohol solution checks right. Therefore, The Tackling Violent Crime Act amendment requires that there be evidence of either instrument malfunction or operator error in using the instrument before the BAC can be questioned through evidence of low alcohol consumption.

The courts have found these AIs to be highly reliable:

The sum of the tests and checks leaves no room for a reasonable doubt to be held, absent some evidence of malfunction or error. In particular, the calibration check answers any concerns about the approval process or the self testing of the machine. It provides an external independent verification that the actual instrument in question was properly functioning immediately before the subject tests. Scenarios posited to undermine the value of this check are highly speculative. The two sample requirement (to say nothing of the internal detectors) answers concerns about transient conditions such as mouth alcohol or radio frequency interference. No credible hypothesis has been suggested whereby an undetectable error could escape detection with all of these checks in place.5

It is therefore proposed to further reform the rules regarding the proof of BAC by making the BAC at the time of testing produced by an AI irrefutable if a qualified technician ascertained the AI to be in proper working order, followed proper procedures and took two breath samples at least 15 minutes apart.

If it is established that the instrument was in proper operating order, the BAC at the time of testing would be proven for court purposes. The next step is to determine the BAC at the time of the alleged offence. In this regard, the Criminal Code currently provides that the BAC at The time of testing is deemed to be the same as at the time of driving if the tests were performed within two hours the driving.

The Standing Committee recommended that the presumption of identity be extended from two to three hours.

Currently, if the AI tests are not performed within two hours of driving, expert evidence must be called to extrapolate the BAC at the time of testing to the BAC at the time of the alleged offence. The Standing Committee was aware that this time limit can cause problems. It wrote:

This time constraint can be problematic for a police officer if the arrest occurred in a rural area or when he or she was quite busy with other tasks such as assisting crash victims or securing an accident scene. A presumption of identity up to three hours would relieve the prosecutor of the time-consuming and costly obligation of calling a toxicologist in each impaired driving prosecution where the samples were taken outside of the time limit.

Even a three hour time limit could also cause difficulties in some cases particularly those involving an accident. It is settled science that:

If alcohol is consumed on an empty stomach, the blood concentration will usually reach, or be within 20 milligrams per 100 millilitres of, a maximum within approximately 30 minutes, have a variable plateau period, usually within a range of approximately 30 - 60 minutes, and will then decline at a rate generally of 10 to 20 milligrams per 100 millilitres of blood per hour.6

There is no reason to incur the expense to call a toxicologist to calculate what is well known science. It is therefore proposed that, if the tests are taken beyond the two hour period, which is well beyond the 30-60 minute plateau period, 5 mg be added to the BAC at time of testing for each completed half hour to determine the BAC at the time of driving. This calculation gives the benefit to the accused because most people eliminate at a rate close to 10 mg per half hour.

Your views are sought on eliminating the time limit for the presumption of identity by specifying that where the test is beyond two hours, 5 mg will be added to the BAC for each completed half-hour.

Bolus or intervening drinking defences:

It is currently a defence for a person to raise a reasonable doubt that their BAC was over 80 at the time of driving by adducing evidence of consumption that is compatible with both the BAC at the time of testing and with a BAC of 80 or less at the time of driving. The defence has been used in the "bolus drinking" scenario where the accused claims to have guzzled several drinks just before getting into their car so the alcohol was still being absorbed and, consequently, their BAC was under 80 at the time of driving. It has also been used where the driver has consumed alcohol after being stopped by the police or after a collision, supposedly to calm his nerves. It is then argued that this "intervening drink" raised the BAC post-driving and that the driver was actually under 80 at the time of driving.

The bolus drinking defence rewards drinking and dashing, with drivers gambling that they will be able to make it home before their BAC exceeds 80. That is extremely dangerous as any delay could lead to the person being over 80 while still driving. Similarly, the intervening drink, in circumstances where the person should have expected to be required to provide a breath sample, may be an attempt to obstruct justice as the court may not be able to determine beyond a reasonable doubt whether BAC at the time of driving was over 80.

Other jurisdictions have eliminated these defences in legislation by making the BAC at time of testing the offence if that testing occurs within two hours. The ATC suggested, when it appeared before the Standing Committee, that the offence be BAC of 80 at time of testing for this very reason. However, there could be circumstances where the intervening drink defence would be legitimate, for example, where the driver arrived home and takes a drink having no reason to believe that the police will arrive (as a result of a citizen report of erratic driving for example) and demand a breath sample.

Parliament in the Tackling Violent Crime Act has restricted the evidence that can be used to raise a reasonable doubt that the BAC as determined by the approved instrument is the BAC at time of testing by providing that consumption evidence alone is not sufficient. Parliament could, as a matter of public policy, eliminate the "bolus drinking" drinking defence and restrict the "intervening drink" defences by excluding from the calculation of BAC at time of driving, any drinking during the hour preceding driving or while driving; or after a collision, or when the driver should have expected to be required to provide a sample for analysis.

Your views are sought on eliminating the "bolus drinking" defence and restricting the alcohol consumption evidence to post driving consumption where there was no reason to anticipate a police demand for a breath sample.

Disclosure Requests

The right of the accused to make full answer and defence is fundamental. Therefore, the police and the prosecution must disclose all the evidence that is relevant to determining whether the accused committed the alleged offence.

In an impaired driving case where the prosecution is relying on the BAC reading, the issues at trial are:

  • Was the accused in care and control of the vehicle within the three hours preceding the breath test demand?
  • Did the investigating police officer have reasonable and probable grounds to demand that the accused provide a breath sample on an approved instrument?
  • Were the breath tests carried out on an approved instrument?
  • Was the approved instrument operated by a qualified technician?
  • Did the qualified technician ensure that the approved instrument was operating properly?
  • Did the qualified technician operate the approved instrument properly?
  • Were there 15 minutes between breath tests?
  • Were both BAC readings over 80?
  • Was the lower BAC reading over 80?

In the overwhelming majority of cases, these questions can be answered by the testimony of the investigating police officer and the certificate or by the viva voce testimony of the qualified technician. For this reason, defence counsel often tries to keep the certificate out of evidence.

Until the changes in The Tackling Violent Crime Act, the defence could use the Carter or two-beer defence, to have the BAC results simply ignored in favour of the accused's testimony about how much he or she had drunk. Now, there must be evidence of AI malfunction or operator error before a calculation based on the accused's consumption is relevant. Modern AIs will abort the test if they are not within the necessary parameters in order to ensure an accurate analysis, and they also print out the necessary information regarding the test. Instrument malfunction or operator error will rarely, if ever, affect the BAC analysis and the AI will abort or print out the error.

As was pointed out in R. v. Powichrowski7:

To have a reasonable doubt one would have to conclude that there is a reasonable possibility that scientific history was made in the testing of the defendant; that the machine passed over 50 internal checks, accurately measured the known alcohol standard and then immediately went inexplicably and unnoticeably haywire in measurement of the defendant's first sample. It then corrected itself for the second calibration test and produced the targeted result but then went inexplicably haywire again for the defendant's second test but despite the malfunction managed to give a result that was in good agreement with the first test! In my view this is fantasy, not reasonable doubt.

In response to the restrictions on the use of consumption evidence, defence counsel has been seeking access to:

  • The approved instrument itself
  • Software used in the approved instrument
  • Cobra/Adams data
  • Source codes
  • Simulator certification records
  • "Certificate" of Annual Maintenance
  • Service records
  • Usage records
  • Maintenance records
  • RAM printouts
  • Manufacturer's Manual

These disclosure applications implicitly seek to negate the entire ATC AI evaluation and AI approval process and the procedures used to ensure that an AI is functioning properly and is operated properly. There is no reason for repeated disclosure applications regarding things that are not relevant to determining whether the instrument was operating properly at the time the test in question was taken. Typically, none of the information noted above is relevant to that enquiry.

Obviously, the standard alcohol solution test of the AI is vital. However, there are scientifically valid processes that are used to determine that a batch of standard alcohol solution is suitable for use and guidelines on how often the standard alcohol solution once opened and used in testing the AI must be changed. Disclosure should only include the records showing that the standard alcohol solution which was used was from a suitable batch and when the solution was changed.

Parliament could place an onus on the accused to establish the relevance to determining the accuracy of the analysis in question at the trial of what is being sought by way of disclosure.

There could also be a "for greater certainty" clause setting out material that is not relevant including, for example,

  • information regarding the calibration and operation of the ASD. (This because the FAIL on the ASD was corroborated by the even more reliable AI readings)
  • maintenance records or
  • information regarding the internal workings of the AI since the ATC evaluations ensure that the internal processes produce accurate results

Your views are sought on placing limits on disclosure.


Date modified: