Proving Blood Alcohol Concentration Through Breath Samples: Approved Instruments and Certified Evidence

• Author: Karen Jokinen/Peter Keen
• Pages: 325-362

325

Proving Blood Alcohol

Concentration

Through Breath

Samples: Approved

Instruments and

Certied Evidence

18

I. Introduction ............................................. 326

II. Historical Use of Drinking-Pattern Evidence .................... 326

III. Approved Instruments: Unlikelihood of an Undetectable False High ... 327

A. The Legal Reason: What Is Required to Ensure Accuracy? ... 328

B. The Practical Argument .............................. 329

C. The Section 320.31(1) Rule of Conclusive Proof ........... 330

IV. Certicates .............................................. 349

A. Legislation ......................................... 349

B. Notice ............................................ 350

C. Leave to Cross-Examine on the Certicate ................ 351

D. Printout from Approved Instrument .................... 352

V. Elimination Rates and Read Backs ........................... 353

A. Introduction and a Word of Caution .................... 353

B. What Are Elimination Rates? .......................... 353

C. How Read Backs Are Calculated ........................ 354

D. Summary of Read Backs and a Cautionary Note ........... 355

VI. Breath Samples Taken Outside the Oence Time:

The Statutory Read Back ................................... 355

VII. Conclusion .............................................. 361

Appendix 18.1 Approved Breath Analysis Instruments Order .... 362

© 2023 Emond Montgomery Publications. All Rights Reserved.

326 Impaired Driving and Other Criminal Code Driving Oences

I. Introduction

In drinking and driving cases, blood alcohol concentration (BAC) is most commonly

determined by an approved instrument’s analysis of breath samples. Cases of “80 and

over” involving approved instruments are the bread and butter of lawyers litigating

these technical cases. Historically, it was a common practice to challenge the fac-

tual results of an approved instrument, but changes introduced by Bill C-21 made an

approved instrument’s analysis conclusive proof of BAC. This change substantially

curtailed the ability of defence counsel to challenge the results on a factual basis.

Part 2 of Bill C-462 further strengthened the conclusive-proof rule. Although there

were a number of constitutional challenges arising out of the 2008 changes, they were

largely unsuccessful. To date, the 2018 changes to the law have remained intact.

This chapter explains the history behind how counsel used to challenge breath

results on a factual basis. We explain why these challenges are rapidly becoming a

thing of the past by explaining the unlikelihood of an approved instrument producing

a false-high BAC result.

Next, we explain in detail the conclusive-proof rule and the preconditions that

the Crown must establish to rely on this rule. While there are many preconditions, the

Crown will ordinarily be able to establish them by filing a certificate of qualified tech-

nician or a certified copy of a printout from an approved instrument. We will cover

the requirements to file the certificate and printout.

We then briefly describe the toxicology of alcohol elimination. We explain the new

“statutory read back” rule that requires courts to ascertain BAC at the time of the

oence when readings were taken after that time. We include both a formula and a

chart that sets out the calculations a court must make when engaging in a statutory

read back.

II. Historical Use of Drinking-Pattern Evidence

Before the 2008 changes, the Criminal Code3 contained presumptions that an

approved instrument’s results were accurate and that BAC at the time of testing

was the same as at the time of the oence. These were known as the presumptions

of accuracy and identity. These presumptions could be rebutted by “evidence to

the contrary.”4 The most common way to rebut was through the Carter defence,

1 An Act to amend the Criminal Code and to make consequential amendments to other Acts, 2nd Sess,

39th Parl, 2008 (assented to 28 February 2008), SC 2008, c 6 (“the 2008 changes”).

2 An Act to amend the Criminal Code(oences relating to conveyances)and to make consequential

amendments to other Acts, 1st Sess, 42nd Parl, 2018 (assented to 21 June 2018), SC 2018, c 21

(“the 2018 changes”).

3 RSC 1985, c C-46.

4 R v St Pierre, [1995] 1 SCR 791, 1995 CanLII 135.

© 2023 Emond Montgomery Publications. All Rights Reserved.

Chapter 18 Proving Blood Alcohol Concentration Through Breath Samples 327

in which an accused would testify to their consumption of alcohol. A toxicologist

would then testify. The toxicologist would assume the accused’s consumption history

was accurate and, based on the accused’s height, weight, and sex, would project the

accused’s BAC to the time of the oence.5 This was known as a “read back.”

The diculty with this evidence is that despite its success in the past, courts have

become increasingly convinced that individual self-reports of drinking history are

notoriously inaccurate. Approved instruments are recognized as accurate in deter-

mining an individual’s BAC.6 Indeed, the Supreme Court of Canada highlighted the

unreliability of self-drinking reports in R v St-Onge Lamoureux:

This evidence shows both that the probative value of the testimony of the accused

regarding his or her alcohol consumption is debatable and that to admit such testimony

for the purpose of determining whether the test results are valid entails a real risk of

perverting the fact-finding process.7

However, the common law system of justice, with its preference for oral testimony

over other forms of proof, gave undue weight to individual self-reports prior to the

2008 changes.

In 2008, Bill C-2 introduced the rule of conclusive proof, essentially abolishing the

Carter defence. After 2008, the Carter defence could be used only if the readings had

been taken outside the two-hour period or if the Crown failed to establish the statu-

tory preconditions for the rule. This rule placed significant limitations on the use of

individual self-reports.8 The rule was strengthened when section 320.31 was passed.

The statutory read back in subsection 320.31(4) means the rule of conclusive proof

now applies to readings outside the two-hour limit. Today, a self-report of drinking

history is not enough to rebut the rule of conclusive proof. Only when the Crown fails

to prove one of the statutory preconditions underlying section 320.31 will a self-report

combined with toxicological evidence be capable of resulting in an acquittal.

III. Approved Instruments: Unlikelihood of an

Undetectable False High

There is no question that approved instruments can break down or cease to function.

While this is an administrative problem for police detachments, it does not mean that

such errors will result in convicting the innocent. Arguments that this may happen

have become increasingly unsuccessful.

5 R v St-Onge Lamoureux, 2012 SCC 57 at para 17; Regina v Carter, 1985 CanLII 168, 7 OAC 344

(CA); R v St Pierre, ibid.

6 R v St-Onge Lamoureux, ibid at paras 11, 34, 45, 65, 72, 74.

7 R v St-Onge Lamoureux, ibid at para 74.

8 R v St-Onge Lamoureux, ibid.

© 2023 Emond Montgomery Publications. All Rights Reserved.