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  • Jordan Stephen (law student, UNB)

The Scope of Expert Opinion Evidence R v Thomas Edison, 2015 NBQB 074

The New Brunswick Court of Queen’s Bench decision in R v Edison is an important case in relation to the subject matter of expert evidence. The decision clarifies and positively contributes to the jurisprudence on how a judge should determine the proper scope of expert opinion evidence. The judge must draw a fine line between allowing an expert to give their opinion to aid the jury in understanding the facts, and, allowing an expert to give evidence that may influence the trier of fact in a certain direction. Justice Ferguson in Edison gives guidance on this very issue.1

The accused, Mr. Thomas Edison, was charged with two counts of conspiracy to traffic heroin and cocaine.

This was a pre-trial application brought forth by the Crown to determine whether Staff Sergeant Joe Tomeo should be declared an expert witness in relation to the supply, sale and use of heroin and cocaine. Defence counsel did not contest Tomeo’s expertise on the subject matter. Defence counsel did however object to the admissibility of Tomeo’s evidence on the basis that he lacked impartiality. The objection was based on the fact that Tomeo was a high-ranking experienced police officer who “carries an unacceptable bias in favor of the Crown and law enforcement”.2 Therefore, Justice Ferguson dealt with the following issues: whether Tomeo should be considered an expert, and if so, should his testimony be excluded due to his potential lack of impartiality. Finally, if he was allowed to give evidence, to what scope should he be able to give his opinion. The latter is the most important one and is at the heart of this case analysis.3

As Justice Ferguson notes throughout his judgment, defining the scope of expert evidence is crucial. If the expert opinion given is contained to a very narrow scope, then the jury may not be able to properly understand the evidence. If the expert evidence is given with a broad scope, there is a high risk that the trier of fact’s impartial decision may be tainted. If boundaries are not carefully set the testimony of an expert witness may unfairly sway the jury. It is up to the lawyers and judges to do their best to ensure that the opinions given are within this scope. This helps the jury from being unfairly swayed. As Justice Doherty said in R v Abbey, “overreaching is the cause of most of the reversible errors found by the appellate court in the past.”4 Justice Ferguson bears this in mind when determining the proper scope for Tomeo.

The issue before the court is to determine to what extent the testimony of Tomeo should be allowed in relation to the interpretation of coded or furtive language.

Justice Ferguson referred to appellate level cases that guide the leading principles on the proper scope for drug dealing interpretation cases. The case law cited by Justice Ferguson holds that an expert is allowed to give his opinion on the meaning of the words used in the illicit drug business; however not to give his own opinion in respect to the inferences that had to be made from the conversation.5 This is an important distinction. It is up for the jury to make its own inferences. An expert can also give hypothetical conversations that use coded or furtive language to help explain to the jury how patterns of coded conversations are created between individuals provided that they are not related to the facts of the case.6 The jury must make the determination if the language used was furtive or coded in nature by the accused and if so, determine whether the evidence in whole had such cogency that reasonable inferences should be drawn interpreting the coded words by their true meaning.7

Justice Ferguson held that Staff Sergeant Tomeo is qualified as an expert. The scope of his qualification is that he is entitled to testify that people engaged in drug dealings typically speak to each other in coded or furtive language. Tomeo is also permitted to discuss the methods used to decode messages and provide common acronyms affiliated with people engaged in the drug trade. Justice Ferguson further held that Tomeo is allowed to provide hypothetical examples to help explain to the jury how those dealings in drugs may construct coded conversations, for so long as the examples do not reflect the evidentiary matrix of the case. Justice Ferguson finished off his decision by ruling that as per Fougère,8 Tomeo is not entitled to give opinion evidence specifically interpreting or advance an opinion on any purported coded or furtive language in how it can be interpreted.9

In sum, Justice Ferguson properly clarified the current jurisprudence and the evaluation method that other courts should take for similar matters. Allowing Tomeo to be an expert, but not allowing him to give his opinion on his own inference from the facts is a suitable manner with determining the proper scope. It allows the jury to be educated enough to make their own inference, while keeping their factual findings from being influenced by the expert. This decision reiterates the important principle that expert opinion evidence is only admissible when it is necessary. Further this case reinforces the long lasting principle that the judge has a duty to control and contain the scope of expert evidence. In R v Edison, Justice Ferguson exercised his judicial discretion to ensure that Tomeo could testify, but only under a proper scope.


1 R v Thomas Edison, 2015 NBQB 074 [Edison]

2 Ibid at paragraph 4

3 Ibid

4 R v Abbey, 2009 2 SCR 24 [2009] at para 62, 246 CCC (3d) [Abbey]

5 R v Fougère, 1988 NBCA at para 10, [1988] NBJ No. 17

6 Somerville v R, 2012 NBCA at para 33-34, NBJ No. 70

7 Somerville, supra note 6

8 Fougère, supra note 5

9 Edison, supra note 1 at para 73

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