Preparing for Trial

• Author: Eric V. Gottardi/Jennifer A. MacLellan/Michael Lacy/Robin Flumerfelt
• Pages: 21-45

21

2

Preparing

forTrial

I. Introduction ............................................. 22

II. When to Get an Expert ..................................... 23

A. Specialized Factual Witnesses Versus Expert Witnesses ..... 24

B. Admissibility of Expert Testimony ....................... 25

C. Canvassing the Case Law ............................. 25

D. The Usefulness of an Expert ........................... 27

E. Consulting the Opposing Party’s Expert ................. 28

F. Retaining an Expert to Review the Opposing Party’s

ExpertOpinion ..................................... 29

G. Retaining an Expert on Appeal ......................... 30

III. Choosing and Retaining the Right Expert ...................... 31

A. Questions to Consider ............................... 31

B. Sample Retainer Letter ............................... 32

IV. The Report .............................................. 34

A. Evidentiary Status of the Report ........................ 35

B. Counsel’s Communications with the Expert .............. 36

C. Inclusion of Hearsay in the Report ...................... 37

D. Timelines for Disclosing the Expert Report ............... 38

E. Disclosure of the Subject Matter ....................... 40

V. Preparing the Witness ..................................... 43

© [2022] Emond Montgomery Publications. All Rights Reserved.

22 Part I Principles and Procedure

I. Introduction

Expert evidence can play a decisive role in a criminal trial. Even with appropriate lim-

iting instructions and a proper understanding of the role of an expert, the trier of fact

will likely be affected by the impressive qualifications of a witness with specialized

training, education, or experience offering an opinion on a contested issue. Although

every effort is made to “preserve trial by judge and jury [or judge alone and] not

devolve to trial by expert,” it would be naive to conclude that expert opinion evidence

will not significantly impact the fact-finding undertaken by the judge or the jury.1 An

extensive curriculum vitae emphasizing education, publications, seminars, teaching,

and the times that the witness has previously testified in court will increase reliance

on such evidence by the trier of fact.2 And, in some cases, the expert opinion is critical

to the question of whether the allegation has been proven beyond a reasonable doubt.

While it has been suggested that anecdotal concerns about juries being overly influ-

enced by expert evidence are exaggerated and not fully supported by studies under-

taken in the United States,3 there are documented cases of miscarriages of justice

in Canada where expert evidence played a key feature in the criminal prosecution.4

Similarly, expert evidence has led to pre-conviction or post-conviction exoneration in

the DNA context.5 In Canada, there is little opportunity to study the effects of expert

evidence on real-world jury deliberations. However, even when accurately assessed

within its limitations, properly qualified, admissible, and reliable expert evidence can

be “powerful evidence.”6 Unless the use of experts in our adversarial trial model

evolves,7 both Crown prosecutors and defence counsel need to be alive to the use of

expert evidence to advance their respective positions in the criminal trial.

1 White Burgess Langille Inman v Abbott and Haliburton Co., 2015 SCC 23 at paras 17-18.

2 R v Mohan, 1994 CanLII 80, [1994] SCJ No 36 (QL) at para 19.

3 N Vidmar, “Expert Evidence, the Adversary System, and the Jury” (2005) 95:1 American J

Public Health S137.

4 The Honourable Stephen T Goudge, Inquiry into Pediatric Forensic Pathology in Ontario

(Toronto: Ontario Ministry of the Attorney General, 2008), Vol 1, Executive Summary

[Goudge Inquiry]; R v Broomfield, 2014 ONCA 725.

5 Reference re Milgaard (Can), [1992] 1 SCR 866, 1992 CanLII 96.

6 Federal, Provincial and Territorial Heads of Prosecutions Committee Working Group on the

Prevention of Miscarriages of Justice, Report on the Prevention of Miscarriages of Justice

(2004), online: Department of Justice <https://www.justice.gc.ca/eng/rp-pr/cj-jp/ccr-rc/

pmj-pej/index.html> ch 9.

7 See e.g. the “consensus” model approach to expert evidence in some common law jurisdictions.

© [2022] Emond Montgomery Publications. All Rights Reserved.