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Science Evidence v. Technolgy Evidence

Updated: Sep 27, 2022

When qualifying an expert witness, Courts need to carefully consider the scope of expertise of the expert.

Sometimes it is convenient for the Crown, defence, and the Court to all agree that a particular "toxicologist", who is employed by the Government of Ontario in forensic science is qualified to give evidence on the theory and operation of the Intoxilyzer 8000C approved instrument. Sometimes it is convenient for the Crown, defence, and the Court to all agree that a particular "toxicologist" in private practice, who used to be employed by the government should be qualified to give this evidence.

However, the science of measurement is complex. Humans have been struggling with fairness in measurement for thousands of years.

"The Crown may also prove accuracy by calling expert evidence from a toxicologist, or by relying on the common law doctrine of scientific instruments (see: R. v. Wu, [2019] O.J. No. 5000; R. v. McCarthy, 2013 ONSC 599)." R. V. Lombardi, ON SC, [2020] O.J. 5695

Is "accuracy" properly within the scope of evidence that should be provided by a "toxicologist"? What is a toxicologist? Do Courts have a clear concept of what "accuracy" is and do Courts have a clear concept of what a "toxicologist" is?

Does the common law doctrine of scientific instruments make sense from a scientific perspective? In light of R. v. Wu will there be a great deal of Bill C-46 320.31(1)(a) litigation about the science of "scientific instruments"?

Perhaps we have been sloppy in the Canadian Court system in assuming that toxicologists should give evidence, not just about the technical aspects of evidentiary breath testing, but also the science of evidentiary breath testing. Toxicologists may have extensive experience in using evidentiary breath testing instruments. Some of them may publish or teach about such use but does that make them experts in measurement science as it relates to evidentiary breath testing?

Technical evidence is not the same thing as evidence about science. Please see the Science Manual for Canadian Judges.

The following is an excerpt from argument about whether or not a renowned toxicologist from the CFS should be permitted to give scientific evidence (outside of toxicology) as opposed to technical evidence.


The Purposes of raising this argument included:

To separate the concepts of science from technology

To identify the differences between the two types of expertise

To introduce the Science Manual for Canadian Judges

To suggest that a scientist giving evidence, where his/her expertise is limited to technological expertise, is stepping outside his/her qualifications respecting scientific evidence rather than just technological evidence

To limit the Court's findings based on the Crown expert's evidence

To raise a concern as to what happens if someone who is otherwise an eminent scientist in his field, starts stepping into the area of measurement science without having done empirical testing and without being able to be a person who has raised hypotheses and tested them empirically.

To clarify that the weight that should be attached to technology is entirely based upon compliance with quality assurance and quality control.

To challenge the "scientific" evidence from the Crown's expert that deviations from quality assurance and quality control don't make any difference

[Submissions on Expert's Qualification follow]

THE COURT: ...2017. Okay, so the – and is there any issue about – so what’s the issue about

qualification? MS. V: So my understanding from the little paragraph that I’ve provided to Your Honour, the only issue – so there’s no issue that Dr. L is an expert in blood alcohol analysis, the absorption, distribution, and elimination of alcohol in the human body, the effects of alcohol and the theory of breath testing. I understand the issue arises with him as an expert in the operation of the Breathalyzer and Intoxilyzer instruments and the Approved Screening Device, which I can indicate to Your Honour; Dr. L has been qualified as an expert in the operation of the Breathalyzer and Intoxilyzer instruments and the Approved Screening Device more than 500 times in court. So I understand that my friend has some concern about the distinction between technical expert evidence and scientific expert evidence and I’ll allow him to make those submissions. It’s the Crown’s position, and we can certainly go through the process of qualifying Dr. L on the stand, but it’s the Crown’s submission that he is clearly qualified to give expert opinion in this area and that it makes no difference how you label the opinion evidence, in the sense of if it’s technical opinion evidence or scientific opinion evidence. If he’s qualified to give opinion evidence in that area, he’s qualified. He – Your Honour can then assess the evidence and give it the weight that you deem appropriate. THE COURT: Okay. Maybe I should hear from Mr. Biss then about that.

MR. BISS: Your Honour, can I just pass up an excerpt from a document? I’m not sure whether Your Honour is familiar with this; it’s the Science Manual For Canadian Judges.

MS. V: I’m just wondering if Mr. Biss has an extra copy that I can provide to Dr. L? MR. BISS: I only have the three copies with me. Actually, Dr. L can maybe borrow my copy.

THE COURT: Yeah, I’ve read this at some point in time. I can’t remember when or in what context but this is familiar to me. MR. BISS: Your Honour, here’s the practical problem. We have an eminent toxicologist, someone who has been qualified, as my friend pointed out, many, many times before who I’ve seen qualified, who has given evidence many times in court where I’ve participated. He is a toxicologist. If you take a good look at his resume, he is a – clearly a toxicologist. Toxicology includes blood alcohol analysis, it includes the usual concepts of absorption, distribution and elimination of alcohol in the human body, the effects of alcohol, and to some extent includes the theory of breath testing as part of that, but the difficulty that we run into is that courts have to recognize the difference between scientific evidence and technical evidence and that’s why I handed up the little excerpt from the Science Manual For Canadian Judges. So, if I can just give you this analogy. In drug recognition expert cases, the DREs, the police officers that have been qualified are not scientists. They are individuals who have been

given particular training and who following training, who follow technical norms and based on those technical norms they form an opinion. But their opinion depends on them following those particular norms. That’s something different than scientific evidence, which asks and answers why questions, where an issue can be stated as a hypothesis and then can be made subject to empirical testing. Now, with respect to absorption, distribution and elimination of alcohol in the human body, I know that Dr. L has done a great deal of empirical testing with respect to that subject. And in so doing, and I also know that he’s had a great deal of experience in doing blood alcohol analysis. I know that as a result of all of the work that he’s done with people over the years and with respect to doing work with absorption, distribution and elimination of alcohol in the human body, he is able to give scientific evidence about the effects of alcohol. He also understands the theory of breath testing, how it works, the scientific theory behind it. So I can ask him why questions in relationship to that and if I respectfully disagree with his opinion, I can ask questions that are why questions and I can ask him for the empirical proof in relationship to that. The difficulty is that when it comes to something like operation of Intoxilyzer instruments, which is part of what the Crown has in its list, I have no difficulty with Dr. L giving a technical opinion, with Dr. L giving technical evidence with respect to the

operation of an Intoxilyzer instrument. Why? Because on a practical day-to-day basis in his work, doing work in absorption, distribution and elimination of alcohol he uses Intoxilyzer instruments. He also is involved in the teaching of the program and the drafting of the training aid for the Centre of Forensic Sciences. He also has his involvement from the Canadian Society of Forensic Sciences on the Alcohol Test Committee. No doubt about that, but the point is that if it’s a technical opinion, in terms of operation of an Intoxilyzer instrument, it works in relationship to norms and standards and the difficulty we will run into during his evidence, that I’m concerned about, is if we start to get into the question of what happens when people deviate from the norms or the standards? If people don’t follow the training aid of the Centre of Forensic Sciences, if the police officers don’t follow their training, and Your Honour’s already heard some evidence about that with respect to the keeping of an alcohol standard log, the problem with – when we get into him giving evidence about that, I don’t know exactly what evidence he’s going to give in relationship to that, but the problem that we’re going to get into is he can say, “No, well that’s not in the norm, that’s not in the standard.” Yes it is, or yes it isn’t. That’s a technical opinion. But the problem is that if we get into why questions, and particularly if we get into a question where if he’s giving any evidence that says it doesn’t matter, then we get into a scientific issue of him

then giving an opinion and then the question becomes one, has he done any kind of empirical testing to see what happens with instruments out in the field that are aging where such steps have not been taken. And the practical problem is that there – to the best of my knowledge, he has not done that kind of empirical testing. Now, maybe when my friend is seeking to qualify Dr. L she can ask him some questions about what sampling he has done - I’m giving Dr. L some advance notice of maybe the areas that the Crown might ask him. Maybe she can ask him some questions about whether he has done sampling of aging instruments in the field with respect to their calibration across the measuring interval, because after all we’re not talking about the blood alcohol concentration in this case of 100, we’re talking about something more than that, a specific number that’s more than that. So, the question then may be, she may ask him “have you done empirical testing in that area?” I suspect the answer will be no, that he has not done such sampling, that he has not done that kind of empirical study so if any opinion he gives in that respect will not be a scientific opinion. He’s going to be in a position of saying, “well, yes there’s a deviation from the technical norm,” but the question that I’m concerned about, the big area that I’m concerned about, and I think it’s important for the court to start thinking about this right from the very beginning, is what happens if someone who is otherwise an eminent scientist in his field, starts

stepping into the area of measurement science without having done empirical testing and without being able to be a person who has raised hypotheses and tested them empirically. That’s what science is. Your Honour, do you understand my... THE COURT: Okay, so... MR. BISS: ...Distinction?

[Excerpts, Tables, and Figures from the Science Manual for Canadian Judges follow]

[Excerpt from submissions continue] THE COURT: I do. I do understand it. What I want to – the thought that is occurring to me in response to what you’re saying is why don’t we hear his evidence and then you can cross examine him about those points. It may be those – it sounds to me like those are matters that go to the weight to be given to it and it may be that, depending on what the evidence is, it may be that it’s possible that even if he’s qualified on the basis that the Crown seeks to qualify him, from which you’ve just said to me sounds like you agree with his expertise in those areas, when you get to this part where you’re concerned about the basis for an expert opinion about, you know, the failure to deviations... MR. BISS: Deviation from the norm... THE COURT: ...From the standard or whatever and what he might say about that, you cross-examine him and it may be that either it affects the weight of the testimony or it may be that portions of the opinion would have to be not relied upon because they’re beyond the scope of the expertise and it seems to me that the better course of action is to simply get the evidence in and then at the end of the – let’s hear what the answers to all these

questions are and this strikes me as an argument that can be made at the end, whether it’s an argument about weight or whether it’s an argument about admissibility of a portion of the testimony or both, and I can hear it and decide it at that point.

{End of excerpt from submissions]

[What if the questions being asked fall outside of the box of the standards (protocols) and manuals? In other words, if the question is: If the police don't follow the protocol or manual, what difference will it make to the reliability of the measurement? Surely, those are scientific questions rather than technical questions. An scientific expert on the subject of the reliability of a measurement result needs to be a metrologist, not a toxicologist.]

[What if all of the police officers and toxicologists who write the "Best Practices" protocols, standards, and guides, in Canada, are limited to having technical expertise only? Perhaps none of them have performed "what if" empirical experiments on what happens if their protocol, standard, or guide is not followed. Failure to empirically test hypotheses would limit their evidence to technical expertise.]

[What if their "Position Paper" is based entirely on technical expertise rather than science? What if hypotheses stated in the published "Position" are not footnoted , are not the result of empirical testing of the "what ifs", and do not have external references to the world's scientific community.]

[Should these toxicologists with technical expertise be qualified as scientific "experts"?]

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