Issues of Proof

• Author: Nathan Gorham/Jeremy Streeter/Breana Vandebeek
• Pages: 125-146



Issues of Proof

5

I. Introduction ............................................. 

II. Proving the Drug ......................................... 

A. Nature of the Substance .............................. 

B. Continuity ......................................... 

III. Documentary Evidence .................................... 

IV. Expert Evidence .......................................... 

A. General Principles ................................... 

B. Anecdotal Expert Evidence: R v Sekhon .................. 

V. Character and Propensity Evidence ........................... 

A. General Principles About Character Evidence

and Admissibility .................................... 

B. R v Corbett and Cross-Examination on Criminal Record .... 

C. Third-Party Suspects ................................. 

VI. Circumstantial Evidence ................................... 

VII. Hearsay and Co-Conspirator Exception to the Hearsay Rule ....... 

A. General Principles ................................... 

B. Exception for Admissions by the Accused ................ 

C. Drug Purchase Calls ................................. 

D. Narrative .......................................... 

E. Co-Conspirator’s Exception to the Hearsay Rule ........... 

VIII. Vetrovec ................................................ 

Appendix . Sample Certicate of Analyst .................... 

Appendix . Sample Continuity Adavit ..................... 

© 2024 Emond Montgomery Publications. All Rights Reserved.

12 Prosecuting and Defending Drug Cases

I. Introduction

Like in all criminal cases, the law of evidence applies in a drug case. Evidentiary rules

in criminal proceedings are so detailed that they are the subject of independent text-

books. The starting point for the admissibility of any piece of evidence is relevance

and materiality. Evidence is relevant and material if, as a matter of logic and common

sense, it assists in determining an issue at trial.1 Generally, any piece of evidence that

is relevant and material is admissible at trial. However, common law and statutory

rules have developed over time to limit the admissibility of relevant and material evi-

dence that is prejudicial in nature and risks undermining the truth-seeking function

of a trial.

This chapter focuses on common evidentiary issues that arise in a drug trial and

provides practical tips on how to address those issues when they arise. Although

theprocedure of a drug trial is no dierent than a trial for an oence under the

CriminalCode, some evidentiary issues arise with more frequency in drug trials. As a

result, this chapter will begin by outlining what the Crown must do to prove that the

substance involved in the oence is in fact a drug—an issue that relates almost all

Controlled Drugs and Substances Act2 oences—and then address common issues

related to the admissibility and use of the following types of evidence: (1) documen-

tary evidence, (2) expert evidence, (3) character and propensity evidence,

(4)circumstantial evidence, (5) hearsay evidence, and (6) Vetrovec witnesses.

II. Proving the Drug

If possession, tracking, importing, exporting, or production of a substance has been

established, the only thing left to do is prove that it is a controlled substance con-

tained in Schedule I, II, or III of the CDSA. This is normally done by taking a sample

of the substance and sending it to Health Canada for analysis. In order to prove the

drug, the prosecutor must prove both its nature (i.e., what the substance is) and its

continuity (i.e., that the substance tested and the substance found are one and the

same).

Prosecutions under the Cannabis Act3 require the prosecutor to prove not only the

nature of the substance (that it is cannabis) but also the quantity of the substance,

since it is only the possession of certain amounts of cannabis that is prohibited. More-

over, if the allegation is that the accused is in possession of “ illicit” cannabis, the

prosecutor will have to prove not only that the cannabis was illicit but that the accused

knew that it was. A more detailed overview of the Cannabis Act is contained in

Chapter 10, Cannabis Act Oences.

1 R v White, 2011 SCC 13.

2 SC1996, c 19 [CDSA].

3 SC 2018, c 16, s 8(1).

© 2024 Emond Montgomery Publications. All Rights Reserved.