On Friday, February 22, 2008 the Smith Inquiry (properly, the Inquiry into Pediatric Forensic Pathology in Ontario or the Goudge Commission) heard testimony from a panel of judge's, ex-judges and academics who testified about the difficulty of dealing with experts and the necessity of increased skepticism about the various experts that are trotted out from time to time by the Crown to prove their cases. These experts have a generally fatal effect to most defences as they come cloaked in an air of authority and definitiveness that is hard to overcome. Judges hearing cases alone sometimes are able to set aside the infallibility of the expert but juries are ill-equipped without careful and thorough guidance from the defence to overcome the effect of the Crown merely calling this evidence.
All of this has been compounded by the effect of a Supreme Court of Canada ruling called Mohan which has largely eliminated the possibility of excluding an expert from testifying outright. As long as the Crown (or defence for that matter) can show that the proposed witness has some experience, skill or qualification that may render him better qualified than an ordinary person to comment on some relevant matter, then the Mohan decision means that the courts will let that person testify. The Supreme Court of Canada judges in their wisdom decided that the frailties of an expert's testimony are all better dealt with as a matter of "weight" in the final balancing that a judge or jury must carry out in deciding whether or not to convict.
The problem with this approach is that expert testimony is rarely simple. First there is the question of what constitutes well-established science or knowledge, what is more controversial and what is more in the nature of out there speculation. if the jury consisted of a panel of experts in the field that may be something they could sort out but for the most part if an expert says " this is what the science says" then as far as they know that is that. At best a defendant can try to fight back with another expert but that brings up a range of issues including (1) the ability of defence counsel to recognize the problem, (2) the costs involved in finding a responsive expert; and (3) the costs involved in bringing forth this evidence.
Second, while experts are called in specific areas of expertise -- say biology -- they cannot resist the temptation to "roam" (to use the words of the witnesses in Smith Inquiry). I experienced an example of this in a lengthy environmental prosecution I defended a few years ago. The Crown called a series of experts who essentially said that the loss of gravel from a spawning ground would cause damage to the area's ability to support a salmon population -- this was fair evidence in the field of biology. The problem was that the damage had not occurred in the spawning ground but instead had occurred upstream. The biologists could not resist saying that the digging of gravel upstream would cause a loss of gravel in the relevant spawning ground -- something that had nothing to do with biology but was more a matter of engineering or the exotically named field of geography known as "fluvial geomorphology". The biologists had roamed into engineering -- a field they new nothing about and which in fact they had some fundamentally wrongheaded notions about (something which, fortunately I managed to convince the judge they had done).
Third, there is always the issue of assumptions -- experts base their evidence on assumptions. If those assumptions cannot be proven then the expert's evidence is worthless. Unfortunately, the proof of the assumptions often falls by the wayside. Thus for, example an expert says "If the temperature was less than 5 degrees, the person was dead for six hours" If it turns out that the temperature was 10 degrees than this evidence is no help at all but often the first part goes in and no-one ever deals with what the temperature was and so the evidence just becomes "the person was dead for six hours" when, in fact, it may have been three.
Sadly though, unless defence counsel are properly prepared to fight these fights and challenge the evidence -- which requires understanding the evidence -- and judges are willing to exclude witnesses and limit testimony then these issues will not get dealt with. Sadly though unless counsel are funded to do this work it will not get done. Furthermore, given the background of most counsel -- general arts, economics, social sciences or business -- many are just not equipped even if fully funded to go into the depths of this sort of evidence in the manner needed to deal with these problems.
Thus the solution lies in four pieces:
(1) re-visiting Mohan and revising the rules that have kept judges from excluding experts from testifying at all;
(2) funding lawyers to allow them to properly prepare to challenge such evidence;
(3) ensuring that lawyers are properly qualified -- which may mean trying to recruit more lawyers with science backgrounds -- to deal with such evidence;
(4) an increased willingness on the part of courts to keep experts from "roaming" and limiting their evidence to those matters for which the basis can, in fact, be proven.
It will be interesting to see if after the scandal of Dr. Smith's dreadful conduct the courts, the bar and the Parliament and legislatures of Canada are willing to come to grips with these matters.