Section 254(3.1) of the Criminal Code gives certain officers the authority to perform evaluations on persons suspected of driving while impaired by drug:

If a peace officer has reasonable grounds to believe that a person is committing, or at any time within the preceding three hours has committed, an offence under paragraph 253(1)(a) as a result of the consumption of a drug or of a combination of alcohol and a drug, the peace officer may, by demand made as soon as practicable, require the person to submit, as soon as practicable, to an evaluation conducted by an evaluating officer to determine whether the person’s ability to operate a motor vehicle, a vessel, an aircraft or railway equipment is impaired by a drug or by a combination of alcohol and a drug, and to accompany the peace officer for that purpose.

The question then arises what can be made of those findings. The intention of the Crown is normally to submit the findings of the DRE officer as evidence of actual impairment, essential to proving the offence of Operation while Impaired by Drug. The Crown will almost always attempt to use these findings as “expert evidence”, such that the “expert witness” can offer a conclusion that the trier of fact may accept as determinative proof as to the essential element of the offence.

A recent Supreme Court of Canada decision R. v. Bingley, 2017 SCC 12 dealt with the issues relating to DRE evidence as expert evidence.

The SCC essentially answers two questions:

1. Are DRE officers automatically deemed witnesses capable of giving Expert Evidence, by virtue of the CCC provision, such that the common-law Expert Evidence Voir Dire (R. v. Mohan, White v. Abbot, et al) are unnecessary?
2. Is a Mohan voir dire necessary in DRE cases, even if it is not ‘automatically’ superseded by the Code provision?

The answer to the first question – positive for the defence – is “no”. The Code must be explicit in stating that these officers giving this evidence is necessarily admissible as expert evidence. The Code does not do this. So, the common law remains the standard to determine admissibility as expert evidence.

The answer to the second question, however, essentially closes off to the defence the avenue to argue for inadmissibility as expert evidence, even though the common-law necessity for a Mohan Voir Dire technically exists. That is, the DRE evidence is no admissible just because the Code declares it so, but it will be admissible because the Code provision essentially allows it to “pass” the Mohan test virtually every time.

The Mohan Test for admissibility of expert evidence requires five elements: (1) relevance, (2) necessity, (3) absence of an exclusionary rule, (4) special expertise, and (5) probative value outweighing the prejudicial effect of allowing the evidence.

In the case of Bingley, the only issue not conceded is #4, the “special expertise” of the DRE officer. On that point, the Court not only rules that indeed the DRE officer does have special expertise, it does so based on the legislation, which applies to all DRE officers and not just the witness in the Bingley trial itself. It is not that that particular DRE officer proved himself to have “special expertise”, but according to the Court, the legislation itself confers upon all DRE “expertise”, and that it is specifically “expertise outside the experience and knowledge of the trier of fact”. The majority rejects the argument that as novel science, the reliability of the DRE scheme must be proven to the trial judge independent of the authorities conferred under the Code (either by the testifying DRE himself or herself, or a second expert who is informed of the underlying scientific authority). According to the majority, the legislation in and of itself declares the fruits of DRE process as evidence of impairment, and therefore reliable enough for that purpose. As such, so long as the DRE is certified and undertakes the 12-step evaluation, the evidence is reliable, and because it extends beyond what the trial judge knows from experience, they pass the test for “special expertise”, per Bingley.

It does not seem likely.

Bingley deals only with only the one element of the Mohan test that was live in issue in that case: “special expertise”. Of course, this is only one of five elements to the Mohan test; the court does not engage in an analysis on the other four elements because in this particular case, those points were all conceded (appropriately, per the court). However, it is not immediately apparent how a common DRE case could differ from the facts in Bingley such that a novel argument could be raised on one of the other four Mohan criteria.

The Supreme Court does not question the science behind the DRE scheme, deferring to the Parliament’s decision to codify the process in the Criminal Code provision. The fact that Bingley reads the legislation itself as conferring upon DRE officers the ability to make determinations as to level of impairment (having decided Parliament has the power to do so) seems to close off essential arguments against admission under the other four Mohan criteria. That is, one may be tempted to say the evidence is not “relevant” because it is not sufficiently scientific to be determinative of the ultimate issue of impairment. Or one may be tempted to argue the admission of the evidence is overly prejudicial because the weight to be given to it is so minimal, again because of the lack of scientific backing behind the process. But both those arguments will be defeated in the same way the “special expertise” argument was defeated: The Court has ruled that the federal statute declaring it ‘scientific enough’ to determine impairment is determinative. The DRE test is sufficient in determining impairment because the statute says it is, according to the Court. And Parliament has the authority to make such determinations, according to the Court.

Bingley deals with the question of the admissibility DRE evidence as expert evidence. To put this in context, the question is whether or not it can be heard by the court (admissibility as evidence) and whether or not the witness may make a conclusion with respect to a live issue in the trial (admissibility as expert evidence). As set out above, the court finds that indeed, upon the application of the Mohan test for expert evidence, the court shall admit the evidence and furthermore shall allow the witness to make a conclusion:

[24]                          In this case, the reliability of the 12-step evaluation comes from the statutory framework itself. Parliament has determined that the 12-step evaluation performed by a trained DRE constitutes evidence of drug impairment. It may not be conclusive, but it is evidence beyond the experience and knowledge of the trier of fact.

This distinction, of course, is very important. The Court in Bingley was applying the precedent law on the admissibility of expert evidence. Just as it did not attempt to deal with the constitutionality of the scheme and its codification, the Court did not attempt to address the merits of the science or the corresponding weight it ought to be afforded in trials. Even if the legislation is not challenged, Bingley says “this is expert evidence and the conclusions drawn by the expert are evidence for the trier of fact to consider”; it does not say “the conclusion drawn by the expert must form the definitive finding by the trier of fact with respect to that issue at trial.”

Arguments against the weight that ought to be afforded the expert’s conclusions can take all forms: the aim of this challenge is simply to suggest that this expert’s conclusion arising from his application of the DRE methodology is not sufficient proof that your client actually was impaired by drug.

These arguments will be made at the trial level, but many such arguments may well challenge the weight that ought to be given to the DRE test generally. Precedent law can be used in subsequent cases to establish that deficiencies in the DRE formula – while they do not bring into question the expertise of the DRE officer – can and do leave the trier of fact in doubt for any number of reasons. The efficacy of the test can than be chipped away over time as precedent judgments recognize failures in the system and attach limited weight to even strong conclusions about impairment.

On a case-by-case basis, there is another tool available to defence lawyers, one that more closely mirrors Over 80 Breathalyzer cases. Since the expertise afforded the DRE officers and the DRE scheme derive from a very specific and (apparently) reliable method of testing, any deviation from this method may deprive the findings of their probative value.

Of further assistance to the defence is the argument that once any such missteps are established, it is incumbent upon the Crown (or their expert witness) to assure the court that the findings are still useful. That is, they must convince the court that although the test was carried out outside the four-corners of the recognized method, there is some specific reason why the results are still evidence of impairment. Unless the Crown or the witness are versed in the underlying science (to the extend that there is underlying science), it will likely be difficult for them to save the conclusions from losing all weight. Over time, precedent cases may establish “allowable” errors versus fatal errors, but for the time being an argument could be made that this “reliable scientific test” (akin to a Breathalyzer machine, as it were) was used improperly and we cannot trust any results.

Lastly, there is the option for the defence to call a witness to proffer his own conclusion based on the test that was administered. Put bluntly, the seeming subjective and even arbitrary nature of the DRE tests and ensuing “conclusions” make it likely that two experts can look at the exact same test and come to perfectly different conclusions as to whether or not the subject was impaired by drug.

In fact, the defence does not even need an expert to conclude that the subject “passed” the test, thus providing evidence of non-impairment. It may be sufficient in raising a reasonable doubt for a defence expert to simply conclude that for any variety of reasons, the test and its performance are inconclusive; that due to lack of control factors (i.e. without knowing the subject’s medical history), or because the performance was within a range of acceptability, that in his or her expert opinion, all that which the Crown’s DRE officer saw does not amount to a finding of impairedness. Or at least not “by drug”.

It is not out of the realm to envision an abundance of cases in which the Crown expert simply states the result is “impaired”, the defence expert simply states the result of the same test is “not impaired”, and a level of frustration builds to the point where the legislation must be re-thought. Or, on the micro level, this practice is consistently sufficient to raising a reasonable doubt. (The access to justice implications of this are not hard to identify, but this may become a reality in DRE cases).

All in all, the Bingly decision is not in and of itself helpful in the defence of DRE prosecutions. However, it shuts but one door to challenging the DRE scheme. There will likely be no Moran Voir Dire brought to challenge the DRE experts; at least not successfully, in the average DRE case. However, it is possible – even likely – that the scheme may still be challenged on whole, and its application on a case-by-case basis. Bingley does not address and therefore does not affirm the scientific merit of the DRE system. And after all, that is where the most fruitful challenge will need to take place, aimed right at the heart of the legislation and its attempted use to secure convictions based on questionable science and subjective conclusions.