Maintenance of Approved Instruments and Accessory Equipment

Defence lawyers need to understand that there are two dramatically different opinions among scientific experts in Canada about whether or not (annual and periodic) maintenance and inspection of the approved instrument and its accessory equipment are essential to reliability of the measurement results. The issue was recently before the Supreme Court of Canada in R. v. Gubbins,R. v. Vallentgoed. Gubbins/Vallentgoed was an appeal from the Alberta Court of Appeal. You can watch the archived webcast of argument at the SCC.

In Gubbins/Vallentgoed there was a very limited record of scientific evidence. The Defence did not call expert evidence  and did not cross-examine the Crown's expert. The Defence simply relied on stare decisis as a result of the judgment in R. v. St-Onge Lamoureux.

St-Onge Lamoureux was a case about the constitutionality of section 258 (1)(c) of the Criminal Code. The SCC found that the section violated Charter 11(d) but some of the legislation was saved by Charter section 1 BECAUSE of Parliament's purpose in giving the test results a weight consistent with their SCIENTIFIC RELIABILITY.

In St-Onge Lamoureux there was an extensive record of scientific evidence from both sides. That is apparent from the judgment of Justice Deschamps in the following paragraphs. Notice her reference in paragraph [25] to the "expert evidence filed" and the references to "continue to meet manufacturer's specifications" and that "calibration and maintenance are essential 'to the integrity of the breath test program' (p.14)":

In paragraph [26], Justice Deschamps relied upon  a paper by Brian Hodgson "THE VALIDITY OF EVIDENTIAL BREATH ALCOHOL TESTING " at Can. Soc. Forensic Sci. J. Vol. 41. No 2 (2008) pp. 83–96 . Notice the quotation from Hodgson that reads "to achieve scientifically sound results ... good laboratory practice".

So the big question for defence lawyers is "What is good laboratory practice?" Defence lawyers need to learn good laboratory practice. Learning about good laboratory practice "for a forensic purpose" isn't just for DUI lawyers. Every criminal law lawyer needs to be familiar with good laboratory practice in forensic science. Without diligent Court review of inadequacies in forensic quantitative analyses, there will be more miscarriages of justice. See the Motherisk Report by Justice Lang.


Defence lawyers need to learn how evidentiary breath testing equipment and other forensic-purpose measuring instruments work. Defence lawyers need to know what is essential to making sure these instruments are in fact scientifically reliable. You can't just assume that forensic measurements are always reliable. All forensic analysis has an error rate. Our colleagues in the United States are working hard to strengthen forensic science and to re-examine error rates in feature-comparison methods. Unfortunately there is almost no empirical evidence about error rates on approved instruments in the field or revealing that:

1. approved instruments in Canada are generally maintained

2.approved instruments in Canada are generally operated properly, or

3. approved instruments in Canada are generally maintained and inspected.


Neither the Alcohol Test Committee nor the Centre of Forensic Sciences have sampled approved instruments in the field and conducted a study of whether or not they continue to perform to manufacturer's specifications.

Justice Deschamps said the following at paragraph [27]:

It should be noted that police in Ontario receive no metrolological supervision (you can read a lot more about the concept of metrological supervision in international literature at the OIML web site - see in particular the definition in VIML 2.03  and Document D-1 "Considerations for a Law on Metrology") by the Alcohol Test Committee or the Centre of Forensic Sciences. The following is a brief extract from a cross-examination of a CFS scientist:

Q. I want to suggest to you that there is no entity that audits the activities of police services in
relationship to evidentiary breath testing.

A. That's correct. There are recommendations,
but there’s no enforcement, sort of, body that looks at the police service to see whether or not they’re following the recommendations.

In Vallentgoed, the Crown, supported by the evidence of a government scientist, argued a 2012 Position Paper by the Alcohol Test Committee that was prepared after St-Onge, and it would appear in response to St-Onge. The Position Paper does not purport to be a consensus document among the whole scientific community. It does not contain footnotes and references to empirical studies or international scientific literature that support the policy. It is a statement of policy - a position paper - it is not a scientific opinion based on empirical research. I respectfully suggest that it is government-policy-based and not a scientific opinion.

The following is a brief extract from a cross-examination of a CFS scientist on the subject of whether or not the document is policy-based or scientific opinion:

Q. …It is the position of the Alcohol

Test Committee that where these operational recommendations

and procedures are met, the B.A.C. is accurate and reliable.”

You’d agree with me, there’s no footnote to that statement in

the document?

A. Correct.

Q. And there is no indication cited either by

way of footnote or in the way of references of scientific

literature that supports that proposition.

A. That's correct. Because this is a position

paper, not a scientific article.

Q. So, this is not a research paper. This

document’s not a research paper.

A. Correct.

Q. It’s – doesn’t have any references out of

the Canadian Society of Forensic Science Journal.

A. Other than the previous recommendations and

standards listed on the last page.

Q. Yes.

A. It has also a paper by Pawn, Lucas and


Q. All published in the Canadian Society of

Forensic Sciences Journal?

A. Correct.

Q. There are no international references.

A. No, there’s not.

Q. No references to any of the documents in

terms – in international metrology or specifically, in

international science measurement related to evidential breath


A. No.

Q. For example, there’s no reference to O-I-ML

standard R-1-2-6 that Brian Hodgson refers to in his paper.

A. Correct.

Q. And there’s no indication that there’s been

any empirical research to support any of the propositions in

this position paper?

A. I’m sure when they were deliberating, they

came up with scientific evidence for that, but that’s not

presented in this paper.

Q. All right.

A. They’re putting forth their position.

The facts in Vallentgoed are interesting. The Crown initially disclosed a maintenance certificate and later more maintenance documents were produced. See paragraph:

[21] The standard disclosure package in the Vallentgoed prosecution included:

(g) Certificate of Annual Maintenance. This is a certificate from the contractor who is retained to maintain the instruments, certifying that the instrument was tested on January 22, 2013 (4 months before the respondent Vallentgoed’s tests), and that it is “in proper working order and continues to meet the manufacturer’s specifications”.


The Alberta Court of Appeal, ultimately had a more extensive set of maintenance documents as part of its record that showed (paragraph 28 of the ABCA decision) "many of the other documents in the package merely record annual maintenance and recalibration". The maintenance documents showed the Alberta Court of Appeal that the instrument had been properly maintained annually at regular intervals by an independent service centre and most importantly that it had been recently re-calibrated. Defence lawyers should review the paragraphs in Vallentgoed that deal with the maintenance actually performed. The description of the maintenance performed on the Vallentgoed instrument reveals that the instrument was re-calibrated or noted as “continues to meet the manufacturer’s specifications” by the independent contractor on each of:


a.    October 14, 2011 paragraph 27 “the instrument was recalibrated”

b.    August 10, 2012 paragraph 28 “begin calibration procedure”

c.     August 13, 2012 paragraph 28 “found to perform within manufacturer’s specifications”

d.    January 22, 2013 paragraph 21(g) “continues to meet the manufacturer’s specifications”

e.  May 12, 2013 and May 21, 2013 paragraph 26 “requires adjustments to be made to channel voltages, internal” and “found to perform within manufacturers specifications”

Defence lawyers need to discuss the significance to the decision of the following finding:

[26]           The entry for the “Repair” on the May 12, 2013 Vallentgoed maintenance log (the day after his testing) provides further information about the work that was done on the instrument that day, and also illustrates the type of information found in some of the maintenance records.

... While the type of service is shown as “Repair” on the maintenance log, the detail shows that “Routine annual” maintenance was performed. What is described as “repair” is at most the installation of “approved modifications”. Some of the parts were cleaned or replaced as indicated, and then the instrument was calibrated to meet the manufacturer’s specifications.


In other words, the Vallentgoed instrument was being regularly "calibrated to meet the manufacturer's specifications". There was a defined "calibration interval". There is a great deal of international scientific literature on the importance of "calibration interval" in measurement science as it relates to reliability rather than "uncertainty growth". You might want to Google these terms and look for documents on establishing a calibration interval. For a good technical discussion see  Chapter 9 of the NASA document "Measurement Uncertainty Analysis Principles and Methods" page 121:

Uncertainty growth over time corresponds to an increase in out-of-tolerance probability over
time, or equivalently, to a decrease in in-tolerance probability or measurement reliability R(t)
over time.


Defence lawyers need to have a clear understanding of the differences between "calibration" and "control test"(what police call a cal. check). If you don't have a good understanding of the distinction you need to take a hands-on course or an on-line course.

The Supreme Court of Canada has denied the Gubbins/Vallentgoed defence appeal of the decision of the Alberta Court of Appeal.


When you read the decision in the SCC note the following items disclosed. You should find the facts easy to distinguish from what we get in Ontario:

[7]                              Other documents in the Crown’s disclosure package included: (a) the Intoxilyzer 5000C Simulator Alcohol Solution Log; (b) the Intoxilyzer 5000C Test Record for alcohol solution change; (c) the Certificate of Annual Maintenance; (d) the Certificate of Annual Maintenance for the standard alcohol solution breath simulator; (e) the Intoxylizer 5000C Use and Calibration Check Log; and (f) the Certificate of an Analyst (Alcohol Standard). These documents provide particulars of the alcohol solution (when its use commenced, when it was changed, as well as when it was tested and found to be suitable) and the instrument itself (when it was sent for annual maintenance and the details of each time the instrument was calibrated). (Italics added)

But what if, unlike R. v. Jackson and R. v. Vallentgoed, we are dealing with an aging Ontario instrument, not recently re-calibrated, where police are not complying with the recommended "Best Practices" of the Alcohol Test Committee? What if the periodic or annual inspection is being carried out by police officers rather than by an independent authorized service centre that is accredited to do calibrations and re-calibrations? What if the inspector/maintenance technician is not following standard operating procedures? What if police are ignoring non-conformance during the annual inspection? What if a re-calibration of the optical bench or the air flow system (important in fail to blow cases) is done by the police themselves rather than by the accredited manufacturer? What if there is no entity that audits the police in Ontario? Some police services are accredited to ISO17025 and are subject to audit in the United States. I respectfully suggest that in any of these circumstances defence lawyers need to turn to the findings about "good laboratory practice" by Justice Deschamps in St-Onge, argue that St-Onge is still good law,  and challenge the scientific reliability of the measurement result. The gold standard for "good laboratory practice" is ISO17025 internationally and particularly the National Research Council in Canada.

Defence lawyers need to discuss these issues and learn about "metrology", i.e. measurement science, and the limitations of Crown expert evidence in the same way that child protection lawyers need to learn about measurement science and the limitations of Children's Aid Society and Motherisk experts. Please see the recommendations for Judges and lawyers at p. 240 of the Motherisk Report by Justice Lang.

Please remember that modern approved instruments don't just quantify ethyl alcohol concentration. They also quantify and make algorithmic decisions using breath flow (very important in failure to blow cases), time, ambient ethyl alcohol thresholds (important under Bill C-46), interferent thresholds, adjustments of zero (very important for control check reliability), and radio frequency interference thresholds. Modern accessory equipment makes algorithmic decisions quantifying temperature (essential for control test reliability). All of these numbers can be found in manufacturer's specifications. Failure to inspect these systems to ensure that the approved instrument or accessory equipment continues to meet manufacturer's specifications may contribute to unreliability.

Defence lawyers in Ontario also need to put a lot of thought and research into the question of the link, the "why?", between lack of/delayed maintenance/inspection and lack of scientific reliability of the measurement results. The Crown will say that there is no link, because the instrument appeared to be working properly - it went through its sequences, ran its self-checks, didn't stall/crash on that particular day or that particular moment (see the video on the Home page), and produced a test record card showing two tests in good agreement with good control tests. The Crown will say that both the breath tech and the CFS expert say that it appears to have been in good working order. That was the issue in R. v. Lam - what is the link between a missed maintenance anniversary and the scientific reliability of the measurement result? The Crown will concede that there is no requirement of causality or proof of true BAC below 80- see St-Onge, but in Ontario, if the 258(1)(c) presumption applies, there must be a link to a lack of scientific reliability of the measurement result. The Defence is not required to prove the operator error or malfunction caused an otherwise under the limit reading to read over the limit, but there needs to be a link to a reasonable doubt about the scientific unreliability of the measurement result.There are many answers to the question of "why", but they escape most members of the legal community. Unfortunately very few lawyers, toxicologists, and Judges understand "why" - what makes these instruments reliable or unreliable. You may need to hire an expert in physics, in analytical chemistry, or on measurement reliability to explain the "why". You'll need to do continuing education to learn how to ask intelligent questions of that expert, cross-examine the government experts, answer difficult questions from the trial Court, and answer difficult questions on appeals. There is a great deal of scientific literature on these subjects. There are also very good hints about the "why" in the Hodgson article relied upon by Justice Deschamps in St-Onge. Don't be discouraged - if you learn this stuff your cross-examination skills and argument skills will improve dramatically.

And then you need to learn "uncertainty of measurement" - don't get distressed - it's on the Ontario high school curriculum - you can do it!

This web site, our online courses at Udemy, and the members-only blog are our attempt at a forum for discussion and learning by defence lawyers about these subjects.