Expert evidence must be grounded in evidence

R. v. Luu, 2010 ONCA 807, released today, makes clear that expert evidence must be grounded in evidence otherwise proven. Despite some interpretations of R. v. Abbey, 2009 ONCA 624 unless the facts underlying an expert's opinion are proven the expert's opinion is valueless. The Court writes:

[21] The test for whether a jury verdict is reasonable is well established: whether the verdict is one that a properly instructed jury acting judicially, could reasonably have rendered: See R. v. Yebes, [1987] 2 S.C.R. 168 at p. 185 and R. v. Biniaris, [2000] 1 S.C.R. 381 at para. 36. The reasons of Arbour J. in Biniaris are extremely helpful in understanding how that test is to be applied by an appellate court. First, it is not enough that the appeal court has some vague unease or lurking doubt about the verdict. The court must still articulate the basis upon which it finds the jury's verdict to be unreasonable. The basis for the finding of unreasonableness may be grounded in judicial experience. As Arbour J. said at para. 40, the concept of acting judicially means "arriving at a conclusion that does not conflict with the bulk of judicial experience". She continued on this theme at para. 41:

It is not particularly significant to describe this judicial oversight as either objective or subjective. It is exercised by an appeal court and therefore it will invariably draw on a collection of judicial experiences. Because of its judicial character, and because it purports to identify features of a case that will give experienced jurists cause for concern, it is imperative that the reviewing court articulate as precisely as possible what features of the case suggest that the verdict reached by the jury was unreasonable, despite the fact that it was not tainted by any erroneous instructions as to the applicable law. … There are many illustrations from the case law of verdicts having been found unreasonable essentially on the strength of accumulated judicial experience. Concerns about various aspects of the frailty of identification evidence have been a recurrent basis, by itself or together with other considerations, for overturning verdicts as unreasonable. [Emphasis added.]

[22] In my view, the explanation for the flawed verdict in this case must lie in the jury's understanding of the expert evidence. Judicial experience, informed by cases such as R. v. Mohan, [1994] 2 S.C.R. 9 and R. v. Truscott (2007), 225 C.C.C. (3d) 321, and the recent report of Justice Goudge of this court stemming from the Inquiry into Pediatric Forensic Pathology in Ontario demonstrate the dangers inherent in failing to adequately and critically examine expert evidence.

[23] In Truscott, at para. 169, this court referred to the shift in forensic medicine from the authoritative experience model to an evidence-based approach as described by Dr. Pollanen, the Chief Forensic Pathologist for Ontario:

In his report and in his testimony before us, Dr. Pollanen described a shift in approach in forensic medicine and in other branches of medicine more generally. Traditionally, expert opinions were largely based on authoritative experience and anecdotal case reports. In the past few decades, and particularly in the last ten years, an alternative model has developed called the "evidence-based approach". This approach requires a critical analysis of peer-reviewed literature and attention to primary reviewable evidence from the postmortem examination. [Emphasis added.]

[24] Elements of the opinions of Dr. Rose and Ms. Lacalamita have about them the resort to authoritative experience and, in key features, lack grounding in the evidence. Most obviously, Dr. Rose changed her opinion that the bullet wound was a contact wound, but was unable to support that change in opinion either through the evidence or any peer-reviewed literature.

[25] Ms. Lacalamita's original opinion that the revolver was more than 1.4 metres from the shirt was undermined by her failure to consider the frailties in the evidence, most importantly, her failure to consider the impact of the rough handling of the shirt and its original storage in the plastic bag. There were other frailties in her opinion, including her use of cotton to conduct her tests, her failure to consider the angle at which the gun was discharged, and her failure to conduct tests at less than 3.5 feet.

[26] To her credit, Ms. Lacalamita did modify her opinion to take into account the problems that were drawn to her attention. The concern is that the full impact of the frailties of the opinion may have been lost on the jury. I say that, in part, because of the jury's question set out above. In hindsight, that question suggests that the jury did not fully appreciate the extent to which Ms. Lacalamita's opinion had been undermined and was prepared to embark on speculation as to the distance the firearm was from the shirt. The question suggests that the jury was prepared to overlook the frailties in Ms. Lacalamita's opinion so clearly elucidated by the trial judge in the main charge. In other words, the jury did not understand the importance of the evidence-based approach as a foundation for the reliability of expert opinion.

[27] In Mohan, at p. 21, Sopinka J. spoke of the dangers of expert evidence:

There is a danger that expert evidence will be misused and will distort the fact-finding process. Dressed up in scientific language which the jury does not easily understand and submitted through a witness of impressive antecedents, this evidence is apt to be accepted by the jury as being virtually infallible and as having more weight than it deserves.

[28] The jury's verdict suggests that it did not subject the expert evidence, especially the evidence of Ms. Lacalamita and Detective Joice, to the critical analysis required with a full appreciation of the reservations inherent in their opinions. The result may have been to distort the fact-finding process.